Mobilize Hybrid Cars

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Summary

The Mobilize Hybrid Cars solution entails shifting trips from fossil fuel–powered internal combustion engine (ICE) cars to more efficient, lower emitting hybrid cars. Hybrid cars include hybrid electric cars (HEVs) and plug-in hybrid electric cars (PHEVs). They are four-wheeled passenger cars that combine an ICE with an electric motor and battery to improve fuel efficiency and reduce emissions. This definition includes hybrid sedans, sport utility vehicles (SUVs), and pickup trucks, but excludes fully electric cars, two-wheeled vehicles, and hybrid commercial or freight vehicles, such as hybrid buses and delivery trucks. Hybrid cars are a transitional climate solution because they are more efficient and produce fewer emissions per distance traveled than do fossil fuel–powered ICE cars but still rely on fossil fuel combustion.

Income & work,Health
Air quality
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Mobilize Hybrid Cars is a Highly Recommended climate solution. By combining internal combustion engines with electric motors, hybrids reduce fuel use and air pollution.
Overview

Hybrid cars reduce fuel consumption and tailpipe emissions by relying on electric propulsion for part of their operation. There are currently more than 45 million hybrids making up 2.2% of the more than two billion global car stock. HEVs provide the same functionality as fossil fuel–powered ICE cars, but combine an ICE with an electric motor and battery to improve fuel efficiency. Unlike electric cars, HEVs do not require external charging; instead, they recharge their battery using regenerative braking and energy from the engine. This allows them to use electric power at low speeds and in stop-and-go traffic, reducing fuel consumption and emissions compared to traditional gasoline or diesel cars. PHEVs work similarly but have larger batteries that can be charged using the electricity grid. This enables them to operate in full-electric mode for a limited distance before switching to hybrid mode when the battery is depleted.

Hybrid cars typically offer better acceleration than their purely fossil fuel–powered ICE counterparts, especially at lower speeds. This is because electric motors deliver instant torque, allowing hybrids to respond quickly when accelerating from a stop. PHEVs tend to have stronger electric motors and thus better acceleration. The high torque at low speeds eliminates the need for inefficient gear changes and allows near-constant operation at optimal conditions because the ICE is usually engaged at efficient conditions. This improves the real-world fuel economy 39–58% compared to fossil fuel–powered ICE cars of similar size (Zhang et al., 2025).

While hybrid cars reduce fuel consumption and tailpipe emissions by relying on electric propulsion for part of their operation, their overall emissions depend on how much they use the ICE versus the electric motor, and, for PHEVs, on the emissions intensity of the electricity source used for charging. PHEVs can offer greater potential for emission reductions if charged from low-carbon electricity sources. If driven primarily in electric mode, PHEVs can significantly reduce GHG emissions compared to fossil fuel–powered ICE cars, but if the battery is not regularly charged, their fuel consumption may be similar to or even higher than standard HEVs (Dornoff, 2021; Plötz et al., 2020).

Hybrid technologies also improve car efficiency by reducing energy losses. First, both HEVs and PHEVs recover energy through regenerative braking, converting kinetic energy into electricity and storing it in the battery (Yang et al., 2024). Second, their electric powertrains are more efficient than those of traditional ICEs, particularly in urban driving conditions where frequent stops and starts are common (Verma et al., 2022). These advantages contribute to lower fuel consumption and emissions compared to fossil fuel–powered ICE cars. However, the environmental benefits of hybrids depend on driving patterns, battery charging habits, and the carbon intensity of the electricity grid used to charge PHEVs.

Hybrid cars reduce emissions of CO₂, methane, and nitrous oxide to the atmosphere by increasing fuel efficiency compared to fossil fuel–powered ICE cars, which emit these gases from their tailpipes. Because they are typically fueled by gasoline, hybrid cars produce more methane than any diesel-fueled cars they might be replacing. As a result, their 20-yr effectiveness at addressing climate change is lower than their 100-yr effectiveness. 

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Credits

Lead Fellow

  • Heather Jones, Ph.D.

  • Cameron Roberts, Ph.D.

Contributors

  • Ruthie Burrows, Ph.D.

  • James Gerber, Ph.D.

  • Yusuf Jameel, Ph.D.

  • Daniel Jasper

  • Alex Sweeney

Internal Reviewers

  • Aiyana Bodi

  • Hannah Henkin

  • Zoltan Nagy, Ph.D. 

  • Ted Otte

  • Amanda D. Smith, Ph.D.

  • Christina Swanson, Ph.D.

Effectiveness

Each million pkm shifted from fossil fuel–powered cars to hybrid cars saves 27.11 t CO₂‑eq on a 100-yr basis (26.94 t CO₂‑eq on a 20-yr basis, Table 1). Fossil fuel–powered cars emit 115.3 t CO₂‑eq/million pkm on a 100-yr basis (116.4 t CO₂‑eq/million pkm on a 20-yr basis). The emissions from fossil fuel–powered ICE cars are calculated from the current global fleet mix which is mostly gasoline and diesel powered cars. PHEVs have lower emissions in countries with large shares of renewable, nuclear, or hydropower generation in their electricity grids (International Transport Forum, 2020; Verma et al., 2022).

We found this by collecting data on fuel consumption per kilometer for a range of HEV and PHEV models (International Energy Agency [IEA], 2021; International Transport Forum, 2020) and multiplying it by the emissions intensity of the fuel the vehicle uses (weighting PHEVs for percentage traveled using fuel). Simultaneously, we collected data on electricity consumption for a range of PHEV models (IEA, 2021; International Transport Forum, 2020), and multiplied them by the global average emissions per kWh of electricity generation. This was then weighted by the share of HEVs (73.4%) and PHEVs (26.6%) of the global hybrid car stock.

The amount of emissions savings for PHEVs depends on how often they are charged, the distance traveled using the electric motor, and the emissions intensity of the electrical grid from which they are charged. Hybrid cars today are disproportionately used in high and upper-middle income countries, where electricity grids emit less than the global average per unit of electricity generated (IEA, 2024). HEVs and PHEVs benefit from braking so are more efficient (relative to fossil fuel–powered ICE cars) in urban areas.

Hybrid cars have higher embodied emissions than fossil fuel–powered ICE cars due to the presence of both an ICE and electric motor with a battery that has a GHG-intensive manufacturing process. This gives them a carbon payback period of 2.6 to under 16 years (Alberini et al., 2019; Duncan et al., 2019) for HEVs and as low as one year for PHEVs (Fulton, 2020). Embodied emissions are outside the scope of this assessment. 

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Table 1. Effectiveness at reducing emissions.

Unit: t CO₂‑eq/million pkm, 100-yr basis

25th percentile 19.51
Mean 22.36
Median (50th percentile) 27.11
75th percentile 65.85
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Cost

Hybrid cars cost on average US$0.01 more per pkm (US$7,200/million pkm) than fossil fuel–powered ICE cars, including purchase price, financing, fuel and electricity costs, and maintenance costs. This is based on a population-weighted average of the cost differential between hybrid and fossil fuel–powered ICE cars in the EU and 11 other countries: Argentina, China, Czechia, India, Indonesia, Lithuania, Malaysia, South Africa, Thailand, Ukraine, and the United States (BEUC, 2021; Furch et al., 2022; IEA, 2022; Isenstadt & Slowik, 2025; Lutsey et al., 2021; Mittal & Shah, 2024; Mustapa et al., 2020; Ouyang et al., 2021; Petrauskienė et al., 2021; Suttakul et al., 2022). The hybrid cost is weighted by the share of car stock of HEVs and PHEVs. 

While this analysis found that hybrid cars are slightly more expensive than fossil fuel–powered ICE cars almost everywhere, the margin is often quite small and hybrids are less expensive in China, Czechia, India, Thailand, and the United States.

This amounts to a cost of US$264/t CO₂‑eq on a 100-yr basis (US$266/t CO₂‑eq avoided emissions on a 20-yr basis, Table 2).

This analysis did not include costs that are the same for both hybrid and fossil fuel–powered ICE cars, including taxes, insurance costs, public costs of building road infrastructure, etc.

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Table 2. Cost per unit of climate impact.

Unit: 2023 US$/t CO₂‑eq , 100-yr basis

Median 264
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Methods and Supporting Data

Methods and Supporting Data

Learning Curve

Hybrid car prices are declining. For every doubling in hybrid car production, costs decline in accordance with the learning rate of approximately 10% (Table 3).

The learning curve for hybrids is expected to continue its historical trend of 6–17% declines in production costs with each generation (Kittner et al., 2020; Ouyang et al., 2021; Weiss et al., 2019). For hybrid cars, production costs are driven more by the integration of electric and internal combustion powertrain components than by advancements in battery technology. Because they still rely on ICEs, hybrids do not experience the same rapid cost declines from battery improvements as fully electric cars. Instead, their cost reductions stem from manufacturing efficiencies, economies of scale, and advancements in hybrid powertrain efficiency and electric components (Weiss et al., 2019).

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Table 3. Learning rate: drop in cost per doubling of the installed solution base %.

Unit: %

25th percentile 8.00
Mean 11.00
Median (50th percentile) 10.00
75th percentile 13.50
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Speed of Action

Speed of action refers to how quickly a climate solution physically affects the atmosphere after it is deployed. This is different from speed of deployment, which is the pace at which solutions are adopted. 

At Project Drawdown, we define the speed of action for each climate solution as emergency brake, gradual, or delayed.

Mobilize Hybrid Cars is a GRADUAL climate solution. It has a steady, linear impact on the atmosphere. The cumulative effect over time builds as a straight line.

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Caveats

Hybrid cars are often considered a transitional technology for climate change mitigation. While they offer immediate reductions in fuel consumption and emissions compared to fossil fuel–powered ICE cars as the world transitions to fully electric transportation, hybrids still rely on the combustion of fossil fuels. The Mobilize Hybrid Cars solution is a move toward lower emissions – not zero emissions. By combining electric and gasoline powertrains, hybrids improve efficiency and reduce GHG emissions without requiring extensive charging infrastructure, making them a practical short-term solution (IEA, 2021). However, as battery costs decline, renewable energy expands, and charging networks improve, fully electric cars (EVs) are expected to replace hybrids as the dominant low-emission transportation option (Plӧtz et al., 2020).

The effectiveness of hybrid cars in reducing fuel consumption and emissions depends significantly on their ability to use electric power, which is influenced by charging habits and regenerative braking efficiency. PHEVs achieve the greatest fuel savings and emissions reductions when they are regularly charged from a low-emissions-intensity electricity grid because this maximizes their electric driving capability and minimizes reliance on the ICE. However, studies show that real-world charging behaviors vary, with some PHEV users failing to charge frequently, leading to higher-than-expected fuel consumption. Regenerative braking also plays a crucial role because it recaptures kinetic energy during deceleration and converts it into electricity to recharge the battery, improving overall efficiency. The extent of these benefits depends on driving conditions, with stop-and-go urban traffic allowing for more energy recovery than highway driving, where regenerative braking opportunities are limited (Plötz et al., 2020).

Hybrid car adoption faces a major obstacle in the form of constraints on battery production. While electric car battery production is being aggressively upscaled (IEA, 2024), building enough batteries to build enough cars to replace a significant fraction of fossil fuel–powered ICE cars is an enormous challenge. This will likely slow down a transition to hybrids, even if consumer demand is high (Milovanoff et al., 2020). This suggests that EV batteries should be prioritized for users whose transport needs are harder to serve with other forms of low-emissions transportation (such as nonmotorized transportation, public transit, etc.). This could include emergency vehicles, commercial vehicles, and vehicles for people who live in rural areas or have disabilities. 

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Current Adoption

Approximately 12 million PHEVs (IEA, 2024) and more than 33 million HEVs (IEA, 2023) are in use worldwide. This corresponds to about 2.2% of the total car stock of 2,022,057,847 (World Health Organization [WHO], 2022) and means that hybrid cars worldwide travel about 1.3 trillion pkm/yr. We assumed this travel would occur in a fossil fuel–powered ICE car if the car’s occupants did not use a hybrid car. Adoption is much higher in some countries, such as Japan, where the global hybrid car stock share was 20–30% in 2023.

To convert this number into pkm traveled by hybrid car, we need to determine the average passenger-distance that each passenger car travels per year. Using population-weighted data from several different countries, the average car carries 1.5 people and travels about 19,500 vehicle-kilometers (vkm)/yr, or an average of 29,250 pkm/yr. Multiplying this number by the number of hybrid cars in use (48.5 million) gives the total travel distance shifted (1.3 trillion pkm) from fossil fuel–powered ICE cars to hybrid cars (Table 4).

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Table 4. Current (2024) adoption level.

Unit: million pkm/yr

Population-weighted mean 1,318,000

Implied travel shifted from fossil fuel–powered cars to hybrid cars.

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Adoption Trend

Globally, the pkm driven in hybrid cars rather than fossil fuel–powered ICE cars increases by an average of about 178,200 million pkm/yr (Table 5). PHEV car purchases between 2019–2023 grew 45%/yr (IEA, 2024), while HEV purchases increased 10% annually between 2021–2023 (IEA, 2021, 2023). Global purchases of hybrid cars are increasing by around 6.1 million cars/yr. This is based on globally representative data (Bloomberg New Energy Finance [BloombergNEF], 2024; Fortune Business Insights, 2025; IEA, 2024; Menes, 2021).

It is worth noting that despite this impressive rate of growth, hybrid cars still have a long way to go before they replace a large percentage of the more than two billion cars currently driven (WHO, 2022).

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Table 5. 2023–2024 adoption trend.

Unit: million pkm/yr

Population-weighted mean 178,200

Implied travel shifted from fossil fuel–powered cars to hybrid cars.

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Adoption Ceiling

The total adoption ceiling for hybrid cars is equal to the total passenger-distance driven by private cars worldwide. Using a population-weighted mean of the average distance (in pkm) traveled per car annually, this translates to about 59 trillion pkm traveled (Table 6).

Replacing every single fossil fuel–powered ICE passenger car with a hybrid car would require an enormous upscaling of hybrid car production capacity, rapid development of charging infrastructure for PHEVs, cost reductions to make hybrid cars more affordable for more people, and technological improvements to make them more suitable for more kinds of drivers and trips. This shift would also face cultural obstacles from drivers who are attached to fossil fuel–powered cars (Roberts, 2022).

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Table 6. Adoption ceiling.

Unit: million pkm/yr

Population-weighted mean 59,140,000

Implied travel shifted from fossil fuel–powered cars to hybrid cars.

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Achievable Adoption

The achievable adoption of hybrid car travel is about 12-30 trillion pkm shifted from fossil fuel–powered ICE vehicles.

Various organizations have produced forecasts of future hybrid car adoption. These are not assessments of feasible adoption per se; they are instead predictions of likely rates of adoption, given various assumptions about the future (Bloomberg New Energy Finance, 2024; Fortune Business Insights, 2025; IEA, 2021, 2023, 2024). But they are useful in that they take a large number of variables into account. To convert these estimates of future likely adoption into estimates of the achievable adoption range, we applied some optimistic assumptions to the numbers in the scenario projections. 

To find a high rate of hybrid car adoption, we assumed that every country could reach the highest rate of adoption projected to occur for any country. Bloomberg (Bloomberg New Energy Finance, 2024) predicts that some countries will reach 20–50% hybrid vehicle stock share by 2030. We therefore set our high adoption rate at 50% adoption worldwide. This corresponds to 1.011 trillion total hybrid cars in use, or 29.6 trillion pkm traveled by hybrid cars (Table 7). An important caveat is that with a global supply constraint in the production of electric car batteries that are also used by hybrids, per-country adoption rates are somewhat zero-sum. Every hybrid car purchased in Japan is one that cannot be purchased somewhere else. This means that for the whole world to achieve 50% hybrid car stock share, global hybrid car production (especially battery production) would have to radically increase. 

To identify a lower feasible rate of electric car adoption, we took the lower end of Bloomberg’s 20–50% global hybrid car adoption ceiling. This is also the current adoption rate in the most intensive country (Japan at 20%), proving it feasible. This translates to 404 million hybrid cars, or 11.8 trillion pkm traveled by hybrid car.

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Table 7. Range of achievable adoption levels.

Unit: million pkm/yr

Current adoption 1,318,000
Achievable – low 11,830,000
Achievable – high 29,570,000
Adoption ceiling 59,140,000
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Hybrid cars currently displace 0.036 Gt CO₂‑eq/yr of GHG emissions from the transportation system on a 100-yr basis (Table 8; 0.036 Gt CO₂‑eq/yr on a 20-yr basis).

If hybrid cars reach 20% of the global private car stock share as BloombergNEF (2024) projects, then with the current number of cars on the road, they will displace 0.321 Gt CO₂‑eq/yr GHG emissions on a 100-yr basis (0.319 Gt CO₂‑eq/yr on a 20-yr basis).

If hybrid cars globally reach 50% of global private car stock share, as BloombergNEF (2024) estimates might happen in some markets, they will displace 0.802 Gt CO₂‑eq/yr GHG emissions on a 100-yr basis (0.796 Gt CO₂‑eq/yr on a 20-yr basis).

If hybrid cars replace 100% of the global car fleet, they will displace 1.603 Gt CO₂‑eq/yr GHG emissions on a 100-yr basis (1.593 Gt CO₂‑eq/yr on a 20-yr basis).

These numbers are based on the present-day average fuel consumption for hybrids and include emissions intensity from electrical grids for PHEVs. If fuel efficiency continues to improve (including hybrids getting lighter) and grids become cleaner, the total climate impact from hybrids cars will increase.

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Table 8. Climate impact at different levels of adoption.

Unit: Gt CO₂‑eq/yr, 100-yr basis

Current adoption 0.036
Achievable – low 0.321
Achievable – high 0.802
Adoption ceiling 1.603
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Additional Benefits

Air Quality

HEVs and PHEVs cars can reduce emissions of air pollutants, including sulfur oxides, sulfur dioxide, particulate matter, nitrogen oxides, and especially carbon monoxide and volatile organic compounds (Requia et al., 2018). Some air pollution reductions are limited (particularly particulate matter and ozone) because hybrid cars are heavy. The added weight can increase emissions from brakes, tires, and wear on the batteries (Carey, 2023; Jones, 2019).

Health

Because hybrid cars have lower tailpipe emissions than fossil fuel–powered ICE cars, they can reduce traffic-related air pollution, which is associated with asthma, lung cancer, increased emergency department visits for respiratory disease, and increased mortality (Anenberg et al., 2019). Transitioning to hybrid cars can reduce exposure to air pollution, improve health, and prevent premature mortality (Garcia et al., 2023; Larson et al., 2020; Peters et al., 2020).

The health benefits of lower traffic-related air pollution vary spatially and – for PHEVs – partly depend on how communities generate electricity (Choma et al., 2020). Racial and ethnic minority communities located near highways and major traffic corridors are disproportionately exposed to air pollution (Kerr et al., 2021). Transitioning to HEVs and PHEVs could improve health in marginalized urban neighborhoods located near highways, industry, or ports (Pennington et al., 2024). These benefits depend on an equitable distribution of hybrid cars and infrastructure to support the adoption of plug-in hybrid cars (Garcia et al., 2023). 

Income and Work

Adopting hybrid cars can lead to savings in a household’s energy burden spent on fuel, or the proportion of income spent on fuel for transportation (Vega-Perkins et al., 2023). Plug-in hybrids can be charged during off-peak times, leading to further reductions in transportation costs (Romm & Frank, 2006). Savings from HEVs and PHEVs may be especially important for low-income households because they have the highest energy burdens (Bell-Pasht, 2024). 

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Risks

There is some criticism against any solution that advocates for car ownership (electric cars in particular and hybrids – which use fossil fuels – by extension) and that the focus should be on solutions such as public transport systems that reduce car ownership and usage (Jones, 2019; Milovanoff et al., 2020).

There is potential for a rebound effect, where improved fuel efficiency encourages people to drive more, potentially offsetting some of the expected fuel and emissions savings. This can occur because lower fuel costs per kilometer make driving more affordable and so increase vehicle use.

There is a risk that allocating the limited global battery supply to hybrid cars might undermine the deployment of solutions that also require batteries but are more effective at avoiding GHG emissions (Castelvecchi, 2021). These could include electric buses, electric rail, and electric bicycles.

Mining minerals necessary to produce hybrid car batteries carries environmental and social risks. Such mining has been associated with significant harm, particularly in lower-income countries that supply many of these minerals (Agusdinata et al., 2018; Sovacool, 2019).

Hybrid cars might also pose additional safety risks due to their higher weight, which means that they have longer stopping distances and can cause greater damage in collisions and to pedestrians and cyclists (Jones, 2019). 

The operating efficiency depends on charging for PHEVs and braking intensity for all hybrids. The results of efficiency studies also depend on assumptions such as car type, fuel efficiency, battery size, electricity grid, km/yr, and car lifetime. 

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Interactions with Other Solutions

Competing

Hybrid cars compete directly with electric cars for adoption as well as for batteries, public resources, and infrastructural investment.

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Traveling by bicycle, sidewalk, public transit network, fully electric car, or smaller electric vehicle (such as electric bicycle) provides a greater climate benefit than traveling by hybrid car. There is an opportunity cost to deploying hybrid cars because those resources could otherwise be used to support these more effective solutions (Asia-Pacific Economic Cooperation [APEC], 2024).

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Dashboard

Solution Basics

million passenger kilometers (million pkm)

t CO₂-eq (100-yr)/unit
019.5127.11median
units/yr
Current 1.318×10⁶ 01.183×10⁷2.957×10⁷
Achievable (Low to High)

Climate Impact

Gt CO₂-eq (100-yr)/yr
Current 0.036 0.3210.802
US$ per t CO₂-eq
264
Gradual

CO₂ , N₂O, BC

Trade-offs

Hybrid cars have higher embodied emissions than fossil fuel–powered ICE cars due to the presence of both an ICE and electric motor with a battery that has a GHG-intensive manufacturing process. While the embodied emissions are higher for hybrid cars than ICE cars, coupling them with operating emissions yields a carbon payback period of several years. Embodied emissions were outside the scope of this assessment.

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Mt CO2-eq/yr
0–4
4–8
8–12
12–16
16–20
> 20
No data

Annual road transportation emissions, 2024

Cars are the largest source of vehicle emissions, which are shown here for urban areas.

Kott, T., Foster, K., Villafane-Delgado, M., Loschen, W., Sicurello, P., Ghebreselassie, M., Reilly, E., and Hughes, M. (2024). Transportation sector - Global road emissions [Data set]. The Johns Hopkins University Applied Physics Laboratory (JHU/APL), USA, Climate TRACE Emissions Inventory. Retrieved March 12, 2025 from, Link to source: https://climatetrace.org  

Mt CO2-eq/yr
0–4
4–8
8–12
12–16
16–20
> 20
No data

Annual road transportation emissions, 2024

Cars are the largest source of vehicle emissions, which are shown here for urban areas.

Kott, T., Foster, K., Villafane-Delgado, M., Loschen, W., Sicurello, P., Ghebreselassie, M., Reilly, E., and Hughes, M. (2024). Transportation sector - Global road emissions [Data set]. The Johns Hopkins University Applied Physics Laboratory (JHU/APL), USA, Climate TRACE Emissions Inventory. Retrieved March 12, 2025 from, Link to source: https://climatetrace.org  

Maps Introduction

Hybrid cars can mitigate climate change across a wide range of geographic regions. However, their effectiveness varies due to spatial differences in driving conditions, vehicle usage patterns, the carbon intensity of local fuel mixes, and the carbon intensity of the charging source for plug-in hybrid electric vehicles (PHEVs). Hybrids are most effective in urban environments with stop-and-go traffic. Unlike fully electric cars, hybrids do not depend on external charging infrastructure, making them more immediately viable in areas where transport electrification is a challenge.

Socioeconomic factors, including fuel prices, vehicle taxes, and the availability of incentives, influence the adoption of hybrids. Hybrids may be most attractive in areas with high gasoline prices and underdeveloped electric charging infrastructure. They can be a practical transition technology in countries where civil society or government institutions have not yet mobilized large-scale investments in charging infrastructure.

Hybrid cars have an advantage in hot and cold climates, where battery range degradation and heating/cooling loads might discourage electric car adoption.

Hybrid cars have already experienced high adoption in regions such as Japan and North America. Looking forward, they could be particularly impactful in South and Southeast Asia, where urban congestion and poor air quality make cleaner vehicles highly desirable but electricity infrastructure remains unreliable; Sub-Saharan Africa, where hybrids offer emission reductions without requiring major grid upgrades; and middle-income countries in Latin America and Eastern Europe, where rising car ownership coupled with energy price volatility makes fuel-efficient hybrids more attractive than fossil fuel–powered cars.

Action Word
Mobilize
Solution Title
Hybrid Cars
Classification
Highly Recommended
Lawmakers and Policymakers
  • Create time-bound government procurement policies and targets to transition government fleets to hybrid cars when fully electric cars aren’t possible.
  • Provide financial incentives such as tax breaks, subsidies, or grants for hybrid car production and purchases that gradually reduce as market adoption increases.
  • Provide complimentary benefits for hybrid car drivers, such as privileged parking areas, free tolls, and access schemes.
  • Use targeted financial incentives to help low-income communities buy hybrid cars and incentivize manufacturers to produce more affordable options.
  • Develop charging infrastructure, ensuring adequate spacing between stations and equitable distribution of stations.
  • Invest in R&D or implement regulations to improve manufacturing, adoption, supply chain standards, and circularity of hybrid cars – particularly batteries.
  • Transition fossil fuel electricity production to renewables while promoting the transition to hybrid cars.
  • Disincentivize fossil fuel–powered ICE car ownership by gradually introducing taxes, penalties, buy-back programs, or other mechanisms.
  • Offer one-stop shops for information on hybrid vehicles, including demonstrations and educational resources on cost savings, environmental impact, and maintenance.
  • Work with industry and labor leaders to construct new hybrid car plants and transition fossil fuel–powered ICE car manufacturing into hybrid car production.
  • Set regulations for sustainable use of hybrid car batteries and improve recycling infrastructure.
  • Join international efforts to promote and ensure supply chain environmental and human rights standards.
  • Incentivize or mandate life-cycle assessments and product labeling (e.g., Environmental Product Declarations).
  • Create, support, or join partnerships that offer information, training, and general support for hybrid car adoption.

Further information:

Practitioners
  • Produce and sell affordable hybrid car models.
  • Collaborate with dealers to provide incentives, low-interest financing, or income-based payment options.
  • Develop charging infrastructure, ensuring adequate spacing between stations and equitable distribution of stations.
  • Offer lifetime warranties for hybrid batteries and easy-to-understand maintenance instructions.
  • Invest in R&D to improve manufacturing, adoption, supply chain standards, and circularity of hybrid cars, particularly batteries.
  • Provide customers with real-world data to help alleviate fuel efficiency concerns.
  • Offer one-stop shops for information on hybrid cars, including educational resources on cost savings, environmental impact, optimal charging, and maintenance.
  • Work with policymakers and labor leaders to construct new hybrid car plants and transition fossil fuel–powered ICE car manufacturing into hybrid car production.
  • Join international efforts to promote and ensure supply chain environmental and human rights standards.
  • Invest in recycling and circular economy infrastructure.
  • Conduct life-cycle assessments and ensure product labeling (e.g., Environmental Product Declarations).
  • Create, support, or join partnerships that offer information, training, and general support for hybrid car adoption.

Further information:

Business Leaders
  • Set time-bound company procurement policies and targets to transition corporate fleets to hybrid cars when fully electric cars aren’t feasible and report on these metrics regularly.
  • Encourage supply chain partners to transition their delivery fleets to hybrid vehicles when fully electric cars aren’t feasible.
  • Take advantage of financial incentives, such as tax breaks, subsidies, or grants for hybrid car purchases.
  • Create purchasing agreements with hybrid car manufacturers to support stable demand and improve economies of scale.
  • Install charging stations and offer employee benefits for hybrid car drivers, such as privileged parking areas.
  • Invest in R&D to improve manufacturing, adoption, supply chain standards, and circularity of hybrid cars – particularly batteries.
  • Work with industry and labor leaders to transition fossil fuel–powered ICE car manufacturing into hybrid car production.
  • Advocate for financial incentives and policies that promote hybrid car adoption.
  • Join international efforts to promote and ensure supply chain environmental and human rights standards.
  • Educate employees, customers, and investors about the company's transition to hybrid cars and encourage them to learn more about them.
  • Offer one-stop shops for information on hybrid cars, including demonstrations and educational resources on cost savings, environmental impact, and maintenance.
  • Create, support, or join partnerships that offer information, training, and general support for hybrid car adoption.

Further information:

Nonprofit Leaders
  • Set time-bound organizational procurement policies and targets to transition fleets to hybrid cars when fully electric cars aren’t feasible.
  • Take advantage of financial incentives, such as tax breaks, subsidies, or grants for hybrid car purchases.
  • Advocate for financial incentives and policies that promote hybrid car adoption.
  • Install charging stations and offer employee benefits for hybrid car drivers, such as privileged parking areas.
  • Advocate for or provide improved charging infrastructure.
  • Offer workshops or support to low-income communities for purchasing and owning hybrid cars.
  • Work with industry and labor leaders to transition fossil fuel–powered ICE car manufacturing into hybrid car production.
  • Join international efforts to promote and ensure supply chain environmental and human rights standards.
  • Advocate for regulations on lithium-ion batteries and investments in recycling facilities.
  • Offer one-stop shops for information on hybrid cars, including demonstrations and educational resources on cost savings, environmental impact, and maintenance.
  • Create, support, or join partnerships that offer information, training, and general support for hybrid car adoption.

Further information:

Investors
  • Invest in hybrid car companies and companies that provide charging equipment or installation.
  • Pressure and support portfolio companies in transitioning their corporate fleets.
  • Pressure portfolio companies to establish and report on time-bound targets for corporate fleet transition and roll-out of employee incentives.
  • Invest in R&D to improve manufacturing, adoption, supply chain standards, and circularity of hybrid cars – particularly batteries.
  • Invest in hybrid car companies, associated supply chains, and end-user businesses like rideshare apps.
  • Join international efforts to promote and ensure supply chain environmental and human rights standards.
  • Create, support, or join partnerships that offer information, training, and general support for hybrid car adoption.
  • Offer low-interest loans for purchasing hybrid cars or charging infrastructure.

Further information:

Philanthropists and International Aid Agencies
  • Set time-bound organizational procurement policies to transition fleets to hybrid cars when fully electric cars aren’t feasible.
  • Install charging stations and offer employee benefits for hybrid car drivers, such as privileged parking areas.
  • Take advantage of financial incentives, such as tax breaks, subsidies, or grants for hybrid car purchases.
  • Advocate for financial incentives and policies that promote hybrid car adoption.
  • Advocate for or provide improved charging infrastructure.
  • Advocate for regulations on lithium-ion batteries and public investments in recycling facilities.
  • Offer financial services such as low-interest loans or grants for purchasing hybrid cars and charging equipment.
  • Offer workshops or support to low-income communities for purchasing and owning hybrid cars.
  • Work with industry and labor leaders to transition fossil fuel–powered ICE car manufacturing into hybrid car production.
  • Join international efforts to promote and ensure supply chain environmental and human rights standards.
  • Offer one-stop shops for information on hybrid vehicles, including demonstrations and educational resources on cost savings, environmental impact, and maintenance.
  • Create, support, or join partnerships that offer information, training, and general support for hybrid car adoption.

Further information:

Thought Leaders
  • If purchasing a new car, buy a hybrid car if fully electric isn’t feasible.
  • Take advantage of financial incentives, such as tax breaks, subsidies, or grants for hybrid car purchases.
  • Share your experiences with hybrid cars through social media and peer-to-peer networks, highlighting the cost savings, benefits, incentive programs, and troubleshooting tips.
  • Advocate for financial incentives and policies that promote hybrid car adoption.
  • Advocate for improved charging infrastructure.
  • Help improve circularity of hybrid car supply chains.
  • Conduct in-depth life-cycle assessments of hybrid cars in particular geographies.
  • Research ways to reduce weight and improve the performance of hybrid cars while appealing to customers.
  • Join international efforts to promote and ensure supply chain environmental and human rights standards.
  • Create, support, or join partnerships that offer information, training, and general support for hybrid car adoption.

Further information:

Technologists and Researchers
  • Improve circularity of hybrid car supply chains.
  • Reduce the amount of critical minerals required for hybrid car batteries.
  • Innovate low-cost methods to improve safety, labor standards, and supply chains in mining for critical minerals.
  • Increase the longevity of batteries.
  • Research ways to reduce weight and improve the performance of hybrid cars while appealing to customers.
  • Improve techniques to repurpose used hybrid car batteries for stationary energy storage.
  • Develop methods of adapting fossil fuel–powered car manufacturing and infrastructure to include electric components.

Further information:

Communities, Households, and Individuals
  • If purchasing a new car, buy a hybrid car when fully electric cars aren’t feasible.
  • Take advantage of financial incentives, such as tax breaks, subsidies, or grants for hybrid car purchases.
  • Share your experiences with hybrid cars through social media and peer-to-peer networks, highlighting the cost savings, benefits, incentive programs, and troubleshooting tips.
  • Help shift the narrative around hybrid cars by demonstrating capability and performance.
  • Advocate for financial incentives and policies that promote hybrid car adoption.
  • Advocate for improved charging infrastructure.
  • Help improve circularity of supply chains for hybrid car components.
  • Join international efforts to promote and ensure supply chain environmental and human rights standards.
  • Create, support, or join partnerships that offer information, training, and general support for hybrid car adoption.

Further information:

Sources
Evidence Base

Consensus of effectiveness in reducing GHG emissions: Mixed

There is a high level of consensus that hybrid cars emit fewer GHGs per kilometer traveled compared to fossil fuel–powered ICE cars. Hybrid cars achieve these reductions by combining an ICE with an electric motor that improves fuel efficiency and, for some models, allow for limited all-electric driving, further reducing fuel consumption and emissions. This advantage is strongest in places where trips are short and require a lot of braking, such as in cities. 

Globally, cars and vans were responsible for 3.8 Gt CO₂‑eq emissions in 2023 – more than 60% of road transport emissions (IEA, 2024).

Major climate research organizations generally see hybrid cars as a transitional means of reducing GHG emissions from passenger transportation. These technologies offer immediate emissions reductions while the electricity grid decarbonizes and battery technology improves. Any improvement to fuel efficiency or time spent driving electrically reduces emissions. These technologies can be a gateway to fully electric cars by eliminating range anxiety and allowing drivers the experience of electric driving without fully committing to the limitations of current EV infrastructure. 

Hybrid cars, while more fuel-efficient than fossil fuel–powered ICE cars, still rely on gasoline or diesel (or potentially advanced biofuels), meaning they continue to produce tailpipe emissions and contribute to air pollution. Additionally, their dual powertrains add complexity, leading to higher embodied emissions, manufacturing costs, increased maintenance requirements, and potential long-term reliability concerns. The added weight from both an ICE and an electric motor, along with a battery pack, can reduce overall efficiency and raise safety concerns. Embodied emissions are outside the scope of this assessment.

The International Council on Clean Transportation (ICCT; Isenstadt & Slowik (2025) estimated that HEVs reduce tailpipe GHG emissions by 30% while costing an average of US$2,000 more upfront. Over a 10-yr period, they offered an estimated fuel cost savings of US$4,500. ICCT expected future HEVs to achieve an additional 15% reduction in GHG emissions, with a decrease in the price premium of US$300–800. PHEVs reduce GHG emissions by 11–30%, depending on emissions intensity of the electric grid and the proportion of distance driven electrically. 

The IEA (2024) noted that a PHEV bought in 2023 will emit 30% less GHGs than a fossil fuel–powered ICE car over its lifetime. This includes full life cycle impacts, including those from producing the car. 

The International Transport Forum (2020) estimated that fossil fuel–powered ICE cars emit 162 g CO₂‑eq/pkm while HEVs emit 132 g CO₂‑eq/pkm and PHEVs emit 124 g CO₂‑eq/pkm. This includes embodied and upstream emissions.

The results presented in this document summarize findings from 12 reviews and meta-analyses and 29 original studies reflecting current evidence from 72 countries, primarily from the IEA’s Global Electric Vehicle Outlook (2024) and Electric Vehicles: Total Cost of Ownership Tool (2022) and the International Transport Forum’s life-cycle analysis on sustainable transportation (2020). We recognize this limited geographic scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions.

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Updated Date

Boost Industrial Efficiency

Submitted by Drawdown Admin on
Sector
Electricity & Industry
Mode
Cut Emissions
Cluster
Enhance Efficiency
Image
Peatland
Coming Soon
On
Description for Social and Search
The Boost Industrial Efficiency solution is coming soon.
Methods and Supporting Data

Methods and Supporting Data

Action Word
Boost
Solution Title
Industrial Efficiency
Classification
Highly Recommended
Updated Date

Deploy LED Lighting

Submitted by Drawdown Admin on
Sector
Electricity
Mode
Cut Emissions
Cluster
Enhance Efficiency
Image
Office building exterior showing many floors of indoor lit offices
Coming Soon
Off
Summary

We define the Deploy LED Lighting solution as replacing energy-inefficient light sources with light-emitting diodes (LEDs). Lighting accounts for 15–20% of electricity use in buildings. Using LEDs reduces the electricity that building lighting consumes, and thereby cuts GHG emissions from global electricity generation.

Income & work,Health
Water quality,Air quality
Description for Social and Search
Using LEDs reduces the electricity that building lighting consumes, and thereby cuts GHG emissions from global electricity generation.
Overview

LED technology for lighting indoor and outdoor spaces is more energy-efficient than other lighting sources currently on the market (Zissis et al., 2021). This is because LEDs are solid-state semiconductors that emit light generated through a direct conversion of the flow of electricity (electroluminescence) rather than heating a tungsten filament to make it glow. More of the electrical energy goes to producing light in an LED lamp than in less-efficient alternative lighting technologies such as incandescent light bulbs or compact fluorescent lamps (CFLs) (Koretsky, 2021; Nair & Dhoble, 2021a). This difference offers significant energy-efficiency gains (see Figure 1).

Globally, lighting-related electricity consumption can account for as much as 20% of the total annual electricity used in buildings (Gayral, 2017; Pompei et al., 2020; Pompei et al., 2022). In 2022, the IEA estimated that total electricity consumption for lighting buildings globally was 1,736 TWh (Lane, 2023). Schleich et al. (2014) and others have argued that buildings consume more electricity for lighting due to a rebound effect when occupants perceive a lighting source as efficient. However, the growing adoption of LED lighting over the years has significantly optimized electricity consumption from building lighting, especially in residential buildings (Lane, 2023).

According to the Intergovernmental Panel on Climate Change (IPCC, 2006), generating electricity from fossil fuels emits CO₂,  methane, and nitrous oxide. Replacing inefficient lamps with LEDs cuts these emissions by reducing electricity demand. LEDs often have a power rating of 4–10 W, which is 3–10 times lower than alternatives. LEDs also last significantly longer: With a lifespan that can exceed 25,000 hours, they vastly outperform incandescent bulbs (1,000 hours) and CFLs (10,000 hours), as shown in Figure 1. LED’s longevity leads to potential long-term savings due to fewer replacements. The amount of light produced per energy input (luminous efficacy) is up to 10 times greater than alternative lighting sources. This means substantially more lighting for less energy.

Figure 1. A comparison of light sources for building lighting (data from Lane, 2023; Mathias et al., 2023; Nair & Dhoble, 2021b; Xu, 2019).

Light source type Power rating (watts) Luminous efficacy (lumens/watt) Lifespan (hours)
Incandescent 40–100 10–15 1,000
CFL 12–20 60–63 10,000
LED 4–10 110–150 25,000–100,000

The International Energy Agency (IEA) and other international bodies report LED market penetration in terms of percentages of the global lighting market (Lane, 2023). We chose this approach to track the impact of adopting LEDs.

Take Action Intro

Would you like to help deploy LED lighting? Below are some ways you can make a difference, depending on the roles you play in your professional or personal life.

These actions are meant to be starting points for involvement and may or may not be the most important, impactful, or doable actions you can take. We encourage you to explore, get creative, and take a step that is right for you!

Albatayneh, A., Juaidi, A., Abdallah, R., & Manzano-Agugliaro, F. (2021). Influence of the advancement in the LED lighting technologies on the optimum windows-to-wall ratio of Jordanians residential buildings. Energies, 14(17), 5446. Link to source: https://www.mdpi.com/1996-1073/14/17/5446

Amann, J. T., Fadie, B., Mauer, J., Swaroop, K., & Tolentino, C. (2022). Farewell to fluorescent lighting: How a phaseout can cut mercury pollution, protect the climate, and save money. Link to source: https://www.aceee.org/research-report/b2202

Behar-Cohen, F., Martinsons, C., Viénot, F., Zissis, G., Barlier-Salsi, A., Cesarini, J. P.,Enouf, O., Garcia, M., Picaud, S., & Attia, D.. (2011). Light-emitting diodes (LED) for domestic lighting: Any risks for the eye? Progress in Retinal and Eye Research, 30(4), 239–257. Link to source: https://doi.org/10.1016/j.preteyeres.2011.04.002

Booysen, M. J., Samuels, J. A., & Grobbelaar, S. S. (2021). LED there be light: The impact of replacing lights at schools in South Africa. Energy and Buildings, 235, 110736. Link to source: https://doi.org/10.1016/j.enbuild.2021.110736

Bose-O'Reilly, S., McCarty, K. M., Steckling, N., & Lettmeier, B. (2010). Mercury exposure and children's health. Current Problems in Pediatric and Adolescent Health Care, 40(8), 186–215. Link to source: https://doi.org/10.1016/j.cppeds.2010.07.002

Build Up. (2019). Overview_Decarbonising the non-residential building stock. European Commission. Retrieved 05 March 2025 from Link to source: https://build-up.ec.europa.eu/en/resources-and-tools/articles/overview-decarbonising-non-residential-building-stock

Cenci, M. P., Dal Berto, F. C., Schneider, E. L., & Veit, H. M. (2020). Assessment of LED lamps components and materials for a recycling perspective. Waste Management, 107, 285-293. Link to source: https://doi.org/10.1016/j.wasman.2020.04.028

Environmental Protection Agency (EPA). (2024). Power sector programs - progress report. Link to source: https://www.epa.gov/power-sector/progress-report

Forastiere, S., Piselli, C., Silei, A., Sciurpi, F., Pisello, A. L., Cotana, F., & Balocco, C. (2024). Energy efficiency and sustainability in food retail buildings: Introducing a novel assessment framework. Energies, 17(19), 4882. Link to source: https://www.mdpi.com/1996-1073/17/19/4882

Fu, X., Feng, D., Jiang, X., & Wu, T. (2023). The effect of correlated color temperature and illumination level of LED lighting on visual comfort during sustained attention activities. Sustainability, 15(4), 3826. Link to source: https://www.mdpi.com/2071-1050/15/4/3826

Gao, W., Sun, Z., Wu, Y., Song, J., Tao, T., Chen, F., Zhang, Y., & Cao, H.(2022). Criticality assessment of metal resources for light-emitting diode (LED) production – a case study in China. Cleaner Engineering and Technology, 6, 100380. Link to source: https://doi.org/10.1016/j.clet.2021.100380

Gasparotto, J., & Da Boit Martinello, K. (2021). Coal as an energy source and its impacts on human health. Energy Geoscience, 2(2), 113–120. Link to source: https://doi.org/10.1016/j.engeos.2020.07.003

Gayral, B. (2017). LEDs for lighting: Basic physics and prospects for energy savings. Comptes Rendus Physique, 18(7), 453–461. Link to source: https://doi.org/10.1016/j.crhy.2017.09.001

Hasan, M. M., Moznuzzaman, M., Shaha, A., & Khan, I. (2025). Enhancing energy efficiency in Bangladesh's readymade garment sector: The untapped potential of LED lighting retrofits. International Journal of Energy Sector Management, 19(3), 569–588. Link to source: https://doi.org/10.1108/ijesm-05-2024-0009

Henneman, L., Choirat, C., Dedoussi, I., Dominici, F., Roberts, J., & Zigler, C. (2023). Mortality risk from United States coal electricity generation. 382(6673), 941–946. Link to source: https://doi.org/doi:10.1126/science.adf4915

Intergovernmental Panel on Climate Change (IPCC). (2006). 2006 IPCC guidelines for national greenhouse gas inventories volume 2: Energy; Chapter 2: Stationary combustion. Link to source: https://www.ipcc-nggip.iges.or.jp/public/2006gl/pdf/2_Volume2/V2_2_Ch2_Stationary_Combustion.pdf

International Energy Agency (IEA). (2022). Targeting 100% LED lighting sales by 2025. Link to source: https://www.iea.org/reports/targeting-100-led-lighting-sales-by-2025

International Energy Agency (IEA). (2023). Global floor area and buildings energy intensity in the net zero scenario, 2010-2030. Retrieved 06 March 2025 from Link to source: https://www.iea.org/data-and-statistics/charts/global-floor-area-and-buildings-energy-intensity-in-the-net-zero-scenario-2010-2030

International Energy Agency (IEA). (2024). World energy balances. IEA. Link to source: https://www.iea.org/data-and-statistics/data-product/world-energy-balances

Iskra-Golec, I., Wazna, A., & Smith, L. (2012). Effects of blue-enriched light on the daily course of mood, sleepiness and light perception: A field experiment. 44(4), 506-513. Link to source: https://doi.org/10.1177/1477153512447528

Kamat, A. S., Khosla, R., & Narayanamurti, V. (2020). Illuminating homes with LEDs in India: Rapid market creation towards low-carbon technology transition in a developing country. Energy Research & Social Science, 66, 101488. Link to source: https://doi.org/10.1016/j.erss.2020.101488

Khan, N., & Abas, N. (2011). Comparative study of energy saving light sources. Renewable and Sustainable Energy Reviews, 15(1), 296–309. Link to source: https://doi.org/10.1016/j.rser.2010.07.072

Koretsky, Z. (2021). Phasing out an embedded technology: Insights from banning the incandescent light bulb in europe. Energy Research & Social Science, 82, 102310. Link to source: https://doi.org/10.1016/j.erss.2021.102310

Lane, K. (2023, 11 July 2023). Lighting. International Energy Agency (IEA). Retrieved 13 December 2024 from Link to source: https://www.iea.org/energy-system/buildings/lighting

Lee, K., Donnelly, S., & Phillips, G. (2024). 2020 U.S. Lighting market characterization. Link to source: https://www.osti.gov/biblio/2371534

Lee, K., Nubbe, V., Rego, B., Hansen, M., & Pattison, M. (2021). 2020 LED manufacturing supply chain. U. S. DOE. Link to source: https://www.energy.gov/sites/default/files/2021-05/ssl-2020-led-mfg-supply-chain-mar21.pdf

Mathias, J. A., Juenger, K. M., & Horton, J. J. (2023). Advances in the energy efficiency of residential appliances in the US: A review. Energy Efficiency, 16(5), 34. Link to source: https://doi.org/10.1007/s12053-023-10114-8

Miah, M. A. R., & Kabir, R. (2023). Energy savings forecast for solid-state lighting in residential and commercial buildings in Bangladesh. IEEE PES 15th Asia-Pacific Power and Energy Engineering Conference (APPEEC), pp. 1-6. Link to source: https://doi.org/10.1109/APPEEC57400.2023.10561921

Moadab, N. H., Olsson, T., Fischl, G., & Aries, M. (2021). Smart versus conventional lighting in apartments - electric lighting energy consumption simulation for three different households. Energy and Buildings, 244, 111009. Link to source: https://doi.org/10.1016/j.enbuild.2021.111009

Moyano, D. B., Moyano, S. B., López, M. G., Aznal, A. S., & Lezcano, R. A. G. (2020). Nominal risk analysis of the blue light from LED luminaires in indoor lighting design. Optik, 223, 165599. Link to source: https://doi.org/10.1016/j.ijleo.2020.165599

Nair, G. B., & Dhoble, S. J. (2021a). 2 - fundamentals of LEDs. In G. B. Nair & S. J. Dhoble (Eds.), The fundamentals and applications of light-emitting diodes (pp. 35–57). Woodhead Publishing. Link to source: https://doi.org/10.1016/B978-0-12-819605-2.00002-1

Nair, G. B., & Dhoble, S. J. (2021b). 6 - general lighting. In G. B. Nair & S. J. Dhoble (Eds.), The fundamentals and applications of light-emitting diodes (pp. 155–176). Woodhead Publishing. Link to source: https://doi.org/10.1016/B978-0-12-819605-2.00006-9

Pattison, M., Hansen, M., Bardsley, N., Elliott, C., Lee, K., Pattison, L., & Tsao, J. (2020). 2019 lighting R&D opportunities. Link to source: https://www.osti.gov/biblio/1618035

Periyannan, E., Ramachandra, T., & Geekiyanage, D. (2023). Assessment of costs and benefits of green retrofit technologies: Case study of hotel buildings in Sri Lanka. Journal of Building Engineering, 78, 107631. Link to source: https://doi.org/10.1016/j.jobe.2023.107631

Placek, M. (2023). LED lighting in the United States - statistics & facts. Statista. Retrieved 09 February 2025 from Link to source: https://www.statista.com/topics/1144/led-lighting-in-the-us/#topicOverview

Pompei, L., Blaso, L., Fumagalli, S., & Bisegna, F. (2022). The impact of key parameters on the energy requirements for artificial lighting in Italian buildings based on standard en 15193-1:2017. Energy and Buildings, 263, 112025. Link to source: https://doi.org/10.1016/j.enbuild.2022.112025

Pompei, L., Mattoni, B., Bisegna, F., Blaso, L., & Fumagalli, S. (2020, 9–12 June 2020). Evaluation of the energy consumption of an educational building, based on the uni en 15193–1:2017, varying different lighting control systems. 2020 IEEE International Conference on Environment and Electrical Engineering and 2020 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe), Madrid, Spain, 2020, pp. 1-6. Link to source: https://doi.org/10.1109/EEEIC/ICPSEurope49358.2020.9160588

Sarigiannis, D. A., Karakitsios, S. P., Antonakopoulou, M. P., & Gotti, A. (2012). Exposure analysis of accidental release of mercury from compact fluorescent lamps (CFLs). Science of The Total Environment, 435–436, 306–315. Link to source: https://doi.org/10.1016/j.scitotenv.2012.07.026

Saunders, H. D., & Tsao, J. Y. (2012). Rebound effects for lighting. Energy Policy, 49, 477-478. Link to source: https://doi.org/10.1016/j.enpol.2012.06.050

Schleich, J., Mills, B., & Dütschke, E. (2014). A brighter future? Quantifying the rebound effect in energy efficient lighting. Energy Policy, 72, 35–42. Link to source: https://doi.org/10.1016/j.enpol.2014.04.028

Schratz, M., Gupta, C., Struhs, T. J., & Gray, K. (2016). A new way to see the light: Improving light quality with cost-effective led technology. IEEE Industry Applications Magazine, 22(4), 55–62. Link to source: https://doi.org/10.1109/MIAS.2015.2459089

United Nations Industrial Development Organization (UNIDO). (2021). SADC member states welcome the introduction of new efficient lighting standards. UNIDO. Retrieved 05 March 2025 from Link to source: https://www.unido.org/news/sadc-member-states-welcome-introduction-new-efficient-lighting-standards

U.S. Department of Energy. (2016). Solid-state lighting R&D plan. Link to source: https://www.energy.gov/sites/prod/files/2016/06/f32/ssl_rd-plan_%20jun2016_2.pdf

U.S. Department of Energy (2024). 2020 U.S. lighting market characterization. Link to source: https://www.energy.gov/sites/default/files/2024-08/ssl-lmc2020_apr24.pdf

World Furniture Online (2017). The lighting fixtures market in Australia and New Zealand. Link to source: https://www.worldfurnitureonline.com/report/the-lighting-fixtures-market-in-australia-and-new-zealand/

Xiong, Y., Guo, H., Nor, D. D. M. M., Song, A., & Dai, L. (2023). Mineral resources depletion, environmental degradation, and exploitation of natural resources: Covid-19 aftereffects. Resources Policy, 85, 103907. Link to source: https://doi.org/10.1016/j.resourpol.2023.103907

Xu, Y. (2019). Chapter 2.1 - nature and source of light for plant factory. In M. Anpo, H. Fukuda, & T. Wada (Eds.), Plant factory using artificial light (pp. 47–69). Elsevier. Link to source: https://doi.org/10.1016/B978-0-12-813973-8.00002-6

Zhang, H., Cai, J., & Braun, J. E. (2023). A whole building life-cycle assessment methodology and its application for carbon footprint analysis of U.S. commercial buildings. Journal of Building Performance Simulation, 16(1), 38–56. Link to source: https://doi.org/10.1080/19401493.2022.2107071

Zissis, G., Bertoldi, P., & Serrenho, T. (2021). Update on the status of LED-lighting world market since 2018. Publications Office of the European Union. Link to source: https://publications.jrc.ec.europa.eu/repository/handle/JRC122760

Credits

Lead Fellow

  • Henry Igugu, Ph.D.

Contributors

  • Ruthie Burrows, Ph.D.

  • James Gerber, Ph.D.

  • Daniel Jasper

  • Alex Sweeney

Internal Reviewers

  • Aiyana Bodi

  • Hannah Henkin

  • Megan Matthews, Ph.D.

  • Ted Otte

  • Amanda D. Smith, Ph.D.

  • Christina Swanson, Ph.D.

Effectiveness

Replacing 1% of the building lighting market with LED lamps avoids approximately 7.09 Mt CO₂‑eq/yr emissions on a 100-yr basis (Table 1) or 7.15 Mt CO₂‑eq/yr on a 20-yr basis.

We estimated this solution’s effectiveness (Table 1) by multiplying the global electricity savings intensity (kWh/%) by an emissions intensity for each GHG emitted (in g/kWh)  due to electricity generation. Using the IEA (2024)’s energy balances data, we estimated emissions intensities of approximately 529 g/kWh for CO₂, 0.07 g/kWh for methane, and 0.01 g/kWh for nitrous oxide. Country-specific data were limited. Therefore, we developed the savings intensity using the IEA’s adoption trend (%/yr) and electricity consumption reduction (kWh/yr) for residential buildings globally (Lane, 2023). We then scaled up the savings intensity to represent all buildings (since LEDs are applicable in all types of buildings), but we could not find global data specifying the energy savings potential of converting the lighting market in nonresidential buildings to LEDs. Notably, artificial lighting’s energy consumption varies across building types (Moadab et al., 2021) and is typically greater in nonresidential buildings (Build Up, 2019). This presents some level of uncertainty, but also suggests that our estimates could be conservative – and that there is potential for even greater savings in nonresidential buildings.

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Table 1. Effectiveness at reducing emissions.

Unit: t CO₂‑eq/% lamps LED/yr, 100-yr basis

Estimate 7090000
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Cost

Our lifetime initial cost estimate of switching 1% of the global building lighting market to LEDs is approximately US$1.5 billion. Because LEDs use less electricity than alternative lamps, they cost less to operate, resulting in operating costs of –US$1.3 billion/yr (i.e., cost savings). Building owners typically are not paid to use LED lighting; therefore, the revenue is zero. After we amortize the initial cost over 30 years, the net annual cost for this solution is –US$1.2 billion/yr globally. Thus, replacing other bulbs with LEDs saves money despite the initial cost.

We estimated the cost (Table 2) by first identifying initial and operating costs from studies that retrofitted buildings with LEDs, such as Periyannan et al. (2023), Hasan et al. (2025), and Forastiere et al. (2024). We then divided the costs by the impact of the LED retrofit on the amount of electricity consumed by lighting in each study and multiplied this by the global electricity savings intensity (kWh/%) we estimated during the effectiveness analysis. The result was the cost per percent of lamps in buildings converted to LED lighting (US$/% lamps LED).

We estimated the cost per unit climate impact by dividing the annual cost savings per adoption unit by the CO₂‑eq emissions reduced yearly per adoption unit (Table 2).

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Table 2. Cost per unit climate impact.

Unit: 2023 US$/t CO₂‑eq, 100-yr basis

Median -175.0

Negative values reflect cost savings.

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Methods and Supporting Data

Methods and Supporting Data

Learning Curve

As LEDs became more common in building lighting, costs dropped significantly in recent years.

Trends based on LED adoption data (Lane, 2023) and the cost of LED lighting (Pattison et al., 2020) showed a 29.7% drop in cost as LED adoption doubled between 2016 and 2019.

The cost data we used to identify the learning curve for this solution (Table 3) are specific to the United States and limited to pre-2020. More recent LED cost data may show additional benefits with respect to cost, but this value may not be applicable for other countries. However, the cost data we analyzed do provide a useful sample of the broader LED cost-reduction trend.

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Table 3. Learning rate: drop in cost per doubling of the installed solution base

Units: %

Estimate 29.7
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Speed of Action

Speed of action refers to how quickly a climate solution physically affects the atmosphere after it is deployed. This is different from speed of deployment, which is the pace at which solutions are adopted.

At Project Drawdown, we define the speed of action for each climate solution as emergency brake, gradual, or delayed.

Deploy LED Lighting is a GRADUAL climate solution. It has a steady, linear impact on the atmosphere. The cumulative effect over time builds as a straight line.

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Caveats

Our effectiveness analysis is based on the current state of LED technology. If the adoption ceiling is attained, further improvements to the amount of light that LEDs generate per unit electricity could enhance the solution’s impact through further reductions in electricity use.

The rebound effect – where building occupants use more lighting in response to increased energy-efficiency of lamps – is a well-established concern (Saunders and Tsao, 2012; Schleich et al., 2014). We attempted to address this concern by using IEA data on actual electricity consumption originating from building lighting to determine both its effectiveness and cost implications (Lane, 2023).

We did not fully account for the cost savings that potentially arise from fewer bulb replacements, since LEDs may replace various types of lamps. Because LEDs last significantly longer than all alternative lamp technologies, building owners may require fewer replacements when using LED lamps compared with other lighting sources.

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Current Adoption

Lane (2023) found that LED lamps represented 50.5% of the lighting market globally for residential buildings in 2022, but does not provide adoption data specific to nonresidential buildings. Studies that provide global or geographically segmented LED adoption data for all building types are also limited. Therefore, we assume 50.5% to be representative of LED adoption across all buildings globally (Table 4).

Other studies highlight adoption levels across various countries. The data captured in these studies and reports provide context with specific adoption levels from different regions (see Geographic Guidance).

The IEA and U.S. Department of Energy (DOE) report that LEDs are increasingly the preferred choice of homeowners and the general building lighting market. This preference is evident in the growing market share of LED lamps sold and installed annually (Lane, 2023; Lee et al., 2024).

In general, the solution’s current adoption globally is substantial, and we recognize that some countries possess more room for the solution to scale. While adoption barriers vary across regions, many countries are establishing lighting standards to drive LED adoption, especially across Africa [(IEA, 2022; United Nations Industrial Development Organization (UNIDO), 2021].

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Table 4. Current (2022) adoption level.

Units: % lamps LED

Estimate 50.5
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Adoption Trend

Adoption of LEDs has grown approximately 3.75%/yr over the past two decades.

Lane (2023) found that the proportion of lamps sold annually for building lighting that are LEDs grew from 1.1% in 2010 to 50.5% in 2022 (Figure 2). We estimated the adoption trend (Table 5) by determining the percentage growth between successive years, and calculating the variances.

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Figure 2. Trend in LED adoption between 2010 and 2022 (adapted from Lane, 2023).

Source: Lane, K. (2023, 11 July 2023). Lighting. International Energy Agency (IEA). Retrieved 13 December 2024 from https://www.iea.org/energy-system/buildings/lighting

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Data on the growth of LEDs across regional building lighting markets are limited. Lee et al. (2024)’s analysis of the U.S. lighting market found 46.5% growth 2010–2020, which translates to 4.65% annually. Zissis et al. (2021) reported 26% growth for France for 2017–2020, which averages 8.67% annually.

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Table 5. 2010–2022 adoption trend.

Units: % lamps LED market share growth/yr

25th percentile 2.85
Mean 4.12
Median (50th percentile) 3.75
75th percentile 5.4
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Adoption Ceiling

The adoption ceiling (Table 6) is 100%, meaning all lamps in buildings are LEDs. Lane (2023) projects 100% LED market penetration by 2030. If current adoption trends continue, 100% LED adoption is a practical and achievable upper limit. However, countries will need to overcome challenges such as regulatory enforcement, financial, and technology access issues, while preventing the entrance of inferior quality LEDs into their lighting market (IEA, 2022).

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Table 6. Adoption ceiling

Units: % lamps LED

Estimate 100
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Achievable Adoption

We estimate a low achievable adoption scenario of 87% based on Statista’s projections about LED lighting market penetration by 2030 (Placek, 2023). The values were similar in Zissis et al. (2021).

For the high achievable scenario, we projected 10 years beyond the 2022 adoption level using the mean adoption trend of 4.12%/yr. This translates to a 41% growth on top of the current adoption level of 50.5%, summing up to a 92% LED adoption level (Table 7).

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Table 7. Range of achievable adoption levels.

Unit: % lamps LED

Current adoption 50.5
Achievable – low 87
Achievable – high 92
Adoption ceiling 100
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We estimated that current adoption cuts about 0.36 Gt CO₂‑eq emissions on a 100-yr basis compared with the previous alternative lighting sources (Table 8). The low achievable adoption scenario of 87% LED lamps could cut emissions 0.62 Gt CO₂‑eq/yr due to reduced electricity consumption, while a high achievable adoption scenario of 92% LED lamps could cut emissions 0.65 Gt CO₂‑eq/yr. If the adoption ceiling of 100% LEDs for lighting buildings is reached, we estimate that 0.71 Gt CO₂‑eq/yr could be avoided (Table 8).

LED lighting could further cut electricity consumption as LED technology continues to improve. However, the technology’s future climate impacts will depend on the emissions of future electricity-generation systems.

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Table 8. Climate impact at different levels of adoption.

Unit: Gt CO₂‑eq/yr, 100-yr basis

Current adoption 0.36
Achievable – low 0.62
Achievable – high 0.65
Adoption ceiling 0.71
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Additional Benefits

Income and Work

Because LEDs use less electricity than fluorescent and incandescent light bulbs (Khan & Abas, 2011), households and businesses using LED technology can save money on electricity costs. The payback period for the initial investment from lower utility bills is about one year for residential buildings and about two months for commercial buildings (Amann et al., 2022). LED lighting can contribute to savings by minimizing energy demand for cooling, since LEDs emit less heat than fluorescent and incandescent bulbs (Albatayneh et al., 2021; Schratz et al., 2016). However, it could also lead to a greater need for space heating in some regions. LED lights also last longer than alternative lighting technologies, which can lead to lower maintenance costs (Schratz et al., 2016).

Health

Reductions in air pollution due to LED lighting’s lower electricity demand decrease exposures to pollutants such as mercury and fine particulate matter generated from fossil fuel-based power plants, improving the health of nearby communities [Environmental Protection Agency (EPA), 2024]. These pollutants have been linked to increased morbidity from cardiovascular and respiratory disease, asthma, infections, and cancer, and to increased risk of mortality (Gasparotto & Martinello, 2021; Henneman et al., 2023). Because LEDs do not contain mercury, they can mitigate small health risks associated with mercury exposure when fluorescent light bulbs break (Bose-O’Reilly et al., 2010; Sarigiannis et al., 2012). Switching to LEDs can also enhance a visual environment and improve occupants’ well-being, visual comfort, and overall productivity when lamps with the appropriate lighting quality and correlated color temperature are selected (Fu et al., 2023; Iskra-Golec et al., 2012; Nair & Dhoble, 2021b).

Air and Water Quality

The lower electricity demand of LEDs could help reduce emissions from power plants and improve air quality (Amann et al., 2022). Additionally, LEDs can mitigate small amounts of mercury found in fluorescent lights (Amann et al., 2022). Mercury contamination from discarded bulbs in landfills can leach into surrounding water bodies and accumulate in aquatic life. LEDs also have longer lifespans than fluorescent and incandescent bulbs (Nair & Dhoble, 2021b) which can reduce the amount of discarded bulbs and further mitigate environmental degradation from landfills. 

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Risks

We found limited data indicating risks with choosing LEDs over other lighting sources. Concerns about eye health raised in the early days of LED adoption (Behar-Cohen et al., 2011) have been allayed by studies that found that LEDs do not pose a greater risk to the eye than comparable lighting sources (Moyano et al., 2020). 

LED manufacturing uses metals like gold, indium, and gallium (Gao et al., 2022). This creates environmental risks due to mining (Xiong et al., 2023) and makes LED supply chains susceptible to macroeconomic uncertainties (Lee et al., 2021). With growing adoption of LED lights, there is also the risk of greater electronic waste at the end of the LED’s lifespan. Therefore, recycling is increasingly important (Cenci et al., 2020). 

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Interactions with Other Solutions

Competing

Some studies demonstrate an increase in the indoor heating requirements when switching to LED lighting from other lighting sources, such as incandescent lamps, that produce more heat than LEDs. The difference is often small, but worth taking into account when adopting LEDs in a building with previously energy-inefficient lighting.

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Dashboard

Solution Basics

% lamps LED

t CO₂-eq (100-yr)/unit/yr
7.09×10⁶
units
Current 50.5 08792
Achievable (Low to High)

Climate Impact

Gt CO₂-eq (100-yr)/yr
Current 0.36 0.620.65
US$ per t CO₂-eq
-175
Gradual

CO₂, CH₄, N₂O, BC

Trade-offs

LED lamp manufacturing creates more emissions than manufacturing other types of lamps. For example, Zhang et al. (2023) compared the manufacturing emissions of a 12.5W LED lamp with a 14W CFL and a 60W incandescent bulb. These light sources provided similar levels of illumination (850–900 lumens). The production of one LED bulb resulted in 9.81 kg CO₂‑eq emissions, while the CFL and incandescent resulted in 2.29 and 0.73 kg CO₂‑eq emissions, respectively. However, LEDs are preferred because their longevity results in fewer LED lamps required to provide the same amount of lighting over time. LEDs can last 25 times longer than incandescent lamps with an identical lumen output (Nair & Dhoble, 2021b; Xu, 2019; Zhang et al., 2023). 

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% lamps LED
< 20
20–40
40–60
> 60
No data

Percentage of lamps that are LEDs, circa 2020

The percentage of lamps used to light buildings that are LEDs varies around the world, with limited data available on a per-country basis.

Miah, M. A. R., & Kabir, R. (2023). Energy savings forecast for solid-state lighting in residential and commercial buildings in Bangladesh. IEEE PES 15th Asia-Pacific Power and Energy Engineering Conference (APPEEC), pp. 1-6, Link to source: https://doi.org/10.1109/APPEEC57400.2023.10561921

U.S. Department of Energy (2024). 2020 U.S. lighting market characterization. Link to source: https://www.energy.gov/sites/default/files/2024-08/ssl-lmc2020_apr24.pdf

World Furniture Online (2017). The lighting fixtures market in Australia and New Zealand. Link to source: https://www.worldfurnitureonline.com/report/the-lighting-fixtures-market-in-australia-and-new-zealand/

Zissis, G., Bertoldi, P., & Serrenho, T. (2021). Update on the status of LED-lighting world market since 2018. Publications Office of the European Union. Link to source: https://publications.jrc.ec.europa.eu/repository/handle/JRC122760

% lamps LED
< 20
20–40
40–60
> 60
No data

Percentage of lamps that are LEDs, circa 2020

The percentage of lamps used to light buildings that are LEDs varies around the world, with limited data available on a per-country basis.

Miah, M. A. R., & Kabir, R. (2023). Energy savings forecast for solid-state lighting in residential and commercial buildings in Bangladesh. IEEE PES 15th Asia-Pacific Power and Energy Engineering Conference (APPEEC), pp. 1-6, Link to source: https://doi.org/10.1109/APPEEC57400.2023.10561921

U.S. Department of Energy (2024). 2020 U.S. lighting market characterization. Link to source: https://www.energy.gov/sites/default/files/2024-08/ssl-lmc2020_apr24.pdf

World Furniture Online (2017). The lighting fixtures market in Australia and New Zealand. Link to source: https://www.worldfurnitureonline.com/report/the-lighting-fixtures-market-in-australia-and-new-zealand/

Zissis, G., Bertoldi, P., & Serrenho, T. (2021). Update on the status of LED-lighting world market since 2018. Publications Office of the European Union. Link to source: https://publications.jrc.ec.europa.eu/repository/handle/JRC122760

Maps Introduction

The Deploy LED Lighting solution can be equally effective at reducing electricity use across global regions because the efficiency gained by replacing other bulbs with LEDs is functionally identical. However, its climate impact will vary with the emissions intensity of each region’s electricity grid. Secondary considerations associated with uptake of LED lighting also can vary with climate and hence geography. In particular, the decrease in heating associated with LED lighting can reduce demands on air conditioning, leading to increased incentive for solution uptake in warmer climates.

Historically, a few countries typically account for the bulk of LEDs purchased. For example, 30% of the 5 billion LEDs sold globally in 2016 were sold in China. In the same period, North America accounted for 15% while Western Europe, Japan, and India represented 11%, 10%, and 8% of the LEDs sold, respectively (Kamat et al., 2020; U.S. DOE, 2016). Essentially, the growing sales of LEDs drove global adoption levels from 17.6% of the building lighting market in 2016 to 50.5% in 2022 (Lane, 2023). However, current adoption still varies considerably around the world. For instance, Lee et al. (2024) reported that LED market penetration in the U.S. was 47.5% in 2020, compared with 43.3% globally in the same period (Lane, 2023). Meanwhile, LED adoption in France was 35% in 2017, and countries in the Middle East such as the United Arab Emirates, Saudi Arabia, and Turkey had over 70% LED adoption that same year; residential buildings in the United Kingdom had 13% LED adoption in 2018, while Japan had 60% LED adoption as of 2019 (Zissis et al., 2021). This demonstrates potential to scale LED adoption in the future, especially in low- and middle-income countries where the bulk of new building occurs (IEA, 2023).

Action Word
Deploy
Solution Title
LED Lighting
Classification
Highly Recommended
Lawmakers and Policymakers
  • Use regulations to phase out and replace energy-inefficient lighting sources with LEDs.
  • Set regulations that encourage sufficient lighting to limit the overuse of LEDs (or rebound effects).
  • Require that public lighting use LEDs.
  • Use financial incentives such as tax breaks, subsidies, and grants to facilitate the transition to LEDs.
  • Revise building energy-efficiency standards to reflect energy savings of LEDs.
  • Develop production standards and mandate labeling for LEDs.
  • Build sufficient inspection capacity for LED manufacturers and penalize noncompliance with standards.
  • Use energy-efficiency purchase agreements to help support utility companies during the transition to LED lighting.
  • Invest in research and development that improves the cost and efficiency of LED lighting.
  • Develop a certification program for LED lighting.
  • Create exchange programs or buy-back programs for inefficient light bulbs.
  • Start demonstration projects to promote LED lighting.
  • Join, support, or create educational programs that raise public awareness about the cost savings and energy-efficiency gains associated with LEDs.

Further information:

Practitioners
  • Take advantage of or advocate for financial incentives such as tax breaks, subsidies, and grants to facilitate the production of LED lighting.
  • Help develop circular supply chains in renovating, remanufacturing, reusing, and redistributing materials.
  • Invest in research and development to improve efficiency and cost of LEDs.
  • Adhere to, or advocate for, national LED standards.
  • Develop, produce, and sell LED lighting that imitates incandescent or other familiar lighting.
  • Consider bundling services with retrofitting companies and collaborating with utility companies to offer rebates or other incentives.
  • Improve self-service of LEDs by reducing obstacles to installation and ensuring LEDs can be easily replaced.
  • Help create positive perceptions of LED lighting by showcasing usage, cost savings, and emissions reductions.
  • Create feedback mechanisms, such as apps that alert users to real-time benefits such as energy and cost savings.
  • Start demonstration projects to promote LED lighting.
  • Join, support, or create educational programs that raise public awareness about the cost savings and energy-efficiency gains associated with LEDs.

Further information:

Business Leaders
  • Retrofit existing operations for LEDs, replace inefficient bulbs, and purchase only LEDs going forward.
  • Help develop circular supply chains in renovating, remanufacturing, reusing, and redistributing LED lighting materials.
  • Take advantage of financial incentives such as tax breaks, subsidies, and grants to facilitate the transition to LED lighting.
  • Invest in research and development that improves the cost and efficiency of LED lighting.
  • Join, support, or create educational programs that raise public awareness about the cost savings and energy-efficiency gains associated with LEDs.

Further information:

Nonprofit Leaders
  • Retrofit existing operations for LEDs, replace inefficient bulbs, and purchase only LEDs going forward.
  • Help develop circular supply chains in renovating, remanufacturing, reusing, and redistributing LED lighting materials.
  • Take advantage of, or advocate for, financial incentives such as tax breaks, subsidies, and grants to facilitate the transition to LED lighting.
  • Advocate for regulations to phase out and replace energy-inefficient lighting sources with LEDs.
  • Advocate for production standards and labeling for LEDs.
  • Call for regulations that encourage sufficient lighting to limit the overuse of LEDs (or rebound effects).
  • Start demonstration projects to promote LED lighting.
  • Help develop, support, or administer a certification program for LED lighting.
  • Create national catalogs of LED manufacturers, suppliers, and retailers.
  • Join, support, or create educational programs that raise public awareness about the cost savings and energy-efficiency gains associated with LEDs.

Further information:

Investors
  • Retrofit existing operations for LEDs, replace inefficient bulbs, and purchase only LEDs going forward.
  • Take advantage of financial incentives such as tax breaks, subsidies, and grants to facilitate the transition to LED lighting.
  • Invest in LED manufacturers, supply chains, and supportive industries.
  • Support research and development to improve the efficiency and cost of LEDs.
  • Invest in LED companies.
  • Fund companies that provide retrofitting services (energy service companies).
  • Invest in businesses dedicated to advancing LED use.
  • Ensure portfolio companies do not produce or support non-LED lighting supply chains.
  • Join, support, or create educational programs that raise public awareness about the cost savings and energy-efficiency gains associated with LEDs.

Further information:

Philanthropists and International Aid Agencies
  • Retrofit existing operations for LEDs, replace inefficient bulbs, and purchase only LEDs going forward.
  • Take advantage of financial incentives such as tax breaks, subsidies, and grants to facilitate the transition to LED lighting.
  • Provide financing such as low-interest loans, grants, and micro-grants to help accelerate LED adoption.
  • Fund companies that provide retrofitting services (energy service companies).
  • Advocate for regulations to phase out energy-inefficient lighting sources and replace them with LEDs.
  • Call for regulations that encourage sufficient lighting to limit the overuse of LEDs (or rebound effects).
  • Start demonstration projects to promote LED lighting.
  • Help develop, support, or administer a certification program for LED lighting.
  • Create national catalogs of LED manufacturers, suppliers, and retailers.
  • Join, support, or create educational programs that raise public awareness about the cost savings and energy-efficiency gains associated with LEDs.

Further information:

Thought Leaders
  • Retrofit buildings for LED lighting, replace inefficient bulbs, and purchase only LEDs going forward.
  • Help create positive perceptions of LED lighting by highlighting your personal usage, cost and energy savings, and emissions reductions.
  • Help develop circular supply chains in renovating, remanufacturing, reusing, and redistributing materials.
  • Take advantage of, or advocate for, financial incentives such as tax breaks, subsidies, and grants to facilitate the transition to LED lighting.
  • Advocate for regulations to phase out energy-inefficient lighting sources and replace them with LEDs.
  • Advocate for LED standards.
  • Advocate for regulations that encourage sufficient lighting and guard against overuse of LEDs (or rebound effects).
  • Start demonstration projects to promote LED lighting.
  • Help develop, support, or administer a certification program for LED lighting.
  • Create national catalogs of LED manufacturers, suppliers, and retailers.
  • Join, support, or create educational programs that raise public awareness about the cost savings and energy-efficiency gains associated with LEDs.

Further information:

Technologists and Researchers
  • Develop circular supply chains in renovating, remanufacturing, reusing, and redistributing materials.
  • Improve the efficiency and cost of LEDs.
  • Improve LED lighting to imitate familiar lighting, offer customers settings, and augment color rendering.
  • Improve self-service of LEDs by reducing obstacles to installation and ensuring LEDs can be replaced individually.
  • Help develop standards for LEDs.
  • Create feedback mechanisms, such as apps that alert users to real-time benefits such as energy and cost savings.

Further information:

Communities, Households, and Individuals
  • Retrofit for LEDs, replace inefficient bulbs, and purchase only LEDs going forward.
  • Help create positive perceptions of LED lighting by highlighting your personal usage, cost and energy savings, and emissions reductions.
  • Help develop circular supply chains in renovating, remanufacturing, reusing, and redistributing materials.
  • Take advantage of or advocate for financial incentives such as tax breaks, subsidies, and grants to facilitate the transition to LED lighting.
  • Advocate for regulations to phase out and replace energy-inefficient lighting sources with LEDs.
  • Advocate for LED standards.
  • Advocate for regulations that encourage sufficient lighting to limit the overuse of LEDs (or rebound effects).
  • Join, support, or create educational programs that raise public awareness about the cost savings and energy-efficiency gains associated with LEDs.

Further information:

Sources
Evidence Base

Consensus of effectiveness in reducing GHG emissions from electricity generation: High

Using LEDs significantly minimizes the electricity required to light buildings, thereby reducing GHG emissions from electricity generation. Many countries are phasing out other lighting sources to reduce GHG emissions (Lane, 2023).

The IEA reported that global adoption of LEDs drove a nearly 30% reduction in annual electricity consumption for lighting in homes between 2010 and 2022 (Lane, 2023). Hasan et al. (2025) indicated that LEDs could reduce the lighting energy usage of buildings (and their resulting GHG emissions) in Bangladesh by 50%. Periyannan et al. (2023) recorded significant electricity savings after evaluating the impact of retrofitting hotels in Sri Lanka with LEDs. Forastiere et al. (2024)’s analysis of the retail buildings in Italy showed an 11% reduction in energy consumption from replacing other lamps with LEDs. Booysen et al., (2021) also achieved significant energy reduction with lighting retrofits in South African educational buildings.

The results presented in this document summarize findings from six original studies and three public sector/multilateral agency reports, which collectively reflect current evidence both globally and from six countries on four different continents. We recognize this limited geographic scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions.

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Updated Date

Deploy District Cooling

Submitted by Drawdown Admin on
Sector
Electricity
Mode
Cut Emissions
Cluster
Enhance Efficiency
Image
A large district cooling facility
Coming Soon
Off
Summary

Deploying district cooling is the process of connecting multiple buildings in a dense area to a single, highly efficient source of cooling. The increased energy efficiency and reduction in use of high global warming potential refrigerants can translate into substantial emissions reductions and lower operating expenses. District cooling systems that integrate cool thermal storage have the potential to significantly reduce electricity demand during peaks when demand for cooling can strain electricity grids. However, the high upfront cost, long-term planning, and large number of stakeholders involved make this a challenging solution, especially in low- and middle-income countries where new demand for cooling is growing. Lack of publicly available data also makes this potential solution difficult to explore in greater depth. Based on our assessment, we will “Keep Watching” this potential solution.

Description for Social and Search
District cooling systems that integrate cool thermal storage have the potential to significantly reduce electricity demand during peaks.
Overview

What is our assessment?

Based on our analysis, deploying district cooling is a potentially impactful option for reducing emissions from buildings as demand for cooling continues to grow. However, upfront cost and project complexity are major barriers to deployment, and a lack of data is a barrier to deeper analysis. This potential solution is therefore classified as “Keep Watching.”

Plausible Could it work? Yes
Ready Is it ready? Yes
Evidence Are there data to evaluate it? No
Effective Does it consistently work? Yes
Impact Is it big enough to matter? Yes
Risk Is it risky or harmful? No
Cost Is it cheap? No

What is it?

District cooling consists of a centralized cooling system that distributes chilled water to multiple buildings through a network of insulated underground pipes. The cooled water absorbs heat from the buildings, replacing the need for air conditioners or chillers in each building. District cooling can produce cooled water from a variety of renewable sources, such as renewable electricity, solar cooling, and natural cooling sources, including seawater, lakewater, rivers, and groundwater. It can even use waste heat from industry to generate cooling. Many systems include thermal energy storage facilities where frozen water, cold water, or phase change materials are cooled when electricity prices are low for use during peak hours to save costs and reduce strain on the electricity grid. District cooling is best applied to high-density areas and can be combined with district heating to provide year-round conditioning. 

Does it work?

When district cooling replaces conventional standalone systems in residential and commercial buildings, it can reduce emissions through two main mechanisms. First, many district cooling systems exchange heat with natural sources of cooling such as oceans, deep lakes, and rivers, a process that can be many times more energy efficient than conventional cooling systems. This results in reduced energy use and reduced emissions from the electricity used to operate the system. Second, district cooling systems can reduce the use of refrigerants with high global warming potentials, which can leak at all stages of a cooling system’s lifespan. When replacing standalone systems, district cooling can significantly reduce the total volume of refrigerants used. In addition, some district cooling systems do not use any refrigerants at all (e.g., exchanging heat with ocean or deep lake water), and many are able to use refrigerants with low global warming potentials. For instance, the Zuidas International Business Hub in the Netherlands adopted a district cooling system that uses lake cooling combined with chillers, reducing emissions by 75% compared to conventional cooling systems. 

Why are we excited?

According to the International Energy Agency (IEA), global carbon emissions from cooling buildings reached 1.02 Gt CO₂‑eq in 2022. The majority of emissions associated with cooling are from standalone systems such as window air conditioners and chillers that serve a single building. District cooling systems are relatively rare at this time, with most capacity found in the United States and the Gulf Arab States. While existing district cooling systems can be made less emitting, there may be greater potential for new systems because demand for cooling is increasing by ~4%/yr as global temperatures rise and as standards of living improve in regions that experience high temperatures. This is raising concerns about the new electricity generating capacity needed when demand peaks on very hot days. District cooling systems can reduce overall energy use for cooling relative to standalone systems, and when paired with cool thermal storage, can significantly reduce demand during peak hours and on hot days. Building owners can enjoy less maintenance costs, more reliable cooling, and increased floor space when district cooling systems replace bulkier standalone cooling systems. In dense areas with good access to natural or low-cost cooling sources, district cooling systems can cost less to operate and offer lifetime savings despite the higher upfront costs. 

Why are we concerned?

Deploying district cooling systems has high upfront costs and requires extensive planning and coordination among a wide range of stakeholders. These projects can face challenges in getting financing due to a lack of confidence for both investors and customers, uncertainty about future loads, and regulatory barriers. These can be especially challenging in low- and middle-income countries where demand for cooling is growing rapidly. Many buildings are likely to invest in standalone systems in the near term, locking them into alternatives and weakening the business case for district systems in the area. Meanwhile, the full potential is difficult to assess due to a lack of data on district cooling systems globally.

Al-Nini, A., Ya, H. H., Al-Mahbashi, N., & Hussin, H. (2023). A Review on Green Cooling: Exploring the Benefits of Sustainable Energy-Powered District Cooling with Thermal Energy Storage. Sustainability, 15(6), 5433. Link to source: https://doi.org/10.3390/su15065433  

Delmastro, C., Martinez-Gordon, R., Lane, K., Voswinkel, F., Chen, O., & Sloots, N. (2023). Space cooling. IEA. Link to source: https://www.iea.org/energy-system/buildings/space-cooling  

Energy Sector Management Assistance Program. (2020). Primer for space cooling (Knowledge Series). World Bank. Link to source: https://documents1.worldbank.org/curated/en/131281601358070522/pdf/Primer-for-Space-Cooling.pdf 

Eveloy, V., & Ayou, D. S. (2019). Sustainable District Cooling Systems: Status, Challenges, and Future Opportunities, with Emphasis on Cooling-Dominated Regions. Energies, 12(2), 235. Link to source: https://doi.org/10.3390/en12020235  

IEA. (2018). The future of cooling: Opportunities for energy-efficient air conditioning. Link to source: https://iea.blob.core.windows.net/assets/0bb45525-277f-4c9c-8d0c-9c0cb5e7d525/The_Future_of_Cooling.pdf  

IEA District Heating and Cooling. (2019). Sustainable district cooling guidelines. International Energy Agency. Link to source: https://iea.blob.core.windows.net/assets/a5da464f-8310-4e0d-8385-0d3647b46e30/2020_IEA_DHC_Sustainable_District_Cooling_Guidelines_new_design.pdf  

International district energy association. (2008). District cooling best practice guide, first edition. Link to source: https://higherlogicdownload.s3.amazonaws.com/DISTRICTENERGY/998638d1-8c22-4b53-960c-286248642360/UploadedImages/Conferences/District_Cooling_Best_Practice_Guide.pdf  

Lienard, V. (n.d.). How can we cool our cities? Euroheat and Power. Retrieved August 18, 2025, from Link to source: https://energy-cities.eu/wp-content/uploads/2025/03/District-cooling_Euro-Heat-and-Power.pdf  

Voswinkel, F., Senat, D., Valle, N. D., D’Angiolini, G., & Callioni, F. (2025, July 28). Staying cool without overheating the energy system. IEA. Link to source: https://www.iea.org/commentaries/staying-cool-without-overheating-the-energy-system  

Werner, S. (2017). International review of district heating and cooling. Energy, 137, 617–631. Link to source: https://doi.org/10.1016/j.energy.2017.04.045  

Credits

Lead Fellow

  • Heather McDiarmid, Ph.D.

Internal Reviewers

  • Christina Swanson, Ph.D.
Action Word
Deploy
Solution Title
District Cooling
Classification
Keep Watching
Updated Date

Deploy Cool Roofs

Submitted by Drawdown Admin on
Sector
Electricity
Mode
Cut Emissions
Cluster
Enhance Efficiency
Image
An image of a white house with a cool roof
Coming Soon
Off
Summary

Cool roofs cut GHG emissions from electricity generation by lowering the amount of cooling required to condition indoor spaces, thereby decreasing the use of air conditioners. Using cool roofs in building design lowers electricity use, improves thermal comfort for building occupants, and is relatively cheap to deploy. However, its potential climate impact is relatively small, and its relevance is largely limited to hot climates where buildings need more cooling than heating to be thermally comfortable. Its application has mostly been in pilot projects, but we conclude that this solution is “Worthwhile” with potential for large-scale deployment.

Description for Social and Search
The Use Cool Roofs solution is coming soon.
Overview

What is our assessment?

Our analysis concludes that the projected climate impact of using cool roofs on buildings is not large enough to be globally significant (>0.1 Gt CO₂‑eq/yr ). However, we consider it “Worthwhile” because it helps reduce electricity consumption in buildings, makes indoor spaces more thermally comfortable, and lessens the urban heat island effect.

Plausible Could it work? Yes
Ready Is it ready? Yes
Evidence Are there data to evaluate it? Limited
Effective Does it consistently work? Yes
Impact Is it big enough to matter? No
Risk Is it risky or harmful? No
Cost Is it cheap? Yes

What is it?

Using cool roofs reduces the amount of electricity needed to cool indoor spaces, thereby cutting GHG emissions from electricity generation. Cool roofs are generally defined as light-colored roofs designed to reflect more sunlight and transfer less solar energy into the interior compared to traditional roofs, thereby reducing cooling loads. Cool roofs can be achieved by applying coatings or using roofing materials with a high solar reflectance index (SRI), which results from high solar reflectance and thermal emittance. These properties ensure that surface temperatures on cool roofs remain substantially cooler than conventional roofs.

Does it work?

Using cool roofs can effectively reduce the amount of air conditioning needed to cool indoor spaces, though their potential to cut annual electricity use in buildings and resulting GHG emissions is minimal. Nonetheless, evidence from real-world applications demonstrates that the surface temperatures of cool roofs can be as much as 28–30°C cooler than conventional roofs on extremely hot afternoons. Other studies have shown that cool roofs can decrease indoor air temperatures by 2–3°C while simultaneously reducing surrounding outdoor air temperatures by about 10°C, thereby minimizing the urban heat island effect.

Several organizations are deploying initiatives to drive cool roof adoption as a passive cooling strategy in the building sector. For example, C40 Cities previously launched a cool roofs program across New York City. Over a six-year period (2009–2015), the initiative resulted in nearly 530,000 m2 of building roof tops being retrofitted as cool roofs. As of 2023, the United States is estimated to have over 232 million m2 of installed cool roofs. Recently, the Million Cool Roofs Challenge organized by the Global Cool Cities Alliance resulted in 1.1 million m2 of additional cool roofs in 2022 across 10 countries, including Indonesia, Mexico, and Rwanda.

Some studies estimate that about 229 billion m2 of roof space existed as of 2022. Given the existing building stock – and the fact that the bulk of projected new construction by 2050 is expected in regions with hot climates – the impact of this potential solution could grow.

Why are we excited?

There are several advantages to using cool roofs in buildings. First, it is cheap to implement, and the incremental cost of applying new coatings or selecting light-colored roofing materials during construction is often minimal compared to conventional roofs. Second, it is expedient as a cooling strategy when buildings are not mechanically air-conditioned or designed to be naturally ventilated. This is important because many countries in hot climates (where cooling is generally required for indoor thermal comfort more than heating) also lack access to reliable electricity, thereby necessitating the use of passive measures in building design. 

In addition, a recent analysis of 77 low- and middle-income countries determined that cooling systems are not readily available, sustainable, or affordable, especially for building applications, placing nearly 4 billion people at risk. Deploying scalable strategies such as cool roofs in buildings helps reduce exposure to these risks, which could lead to greater adoption and climate impact. Several studies have also shown that using cool roofs can help reduce indoor heat stress, especially in hot and humid environments. Others are exploring the concept of cool-colored roofs, where non-white roof materials can provide similar cooling effects while preserving aesthetic choice for building owners and developers. 

Why are we concerned?

Despite the advantages of using cool roofs as a potential climate solution, a few challenges exist. Some studies have shown that cool roofs can slightly increase heating loads during winter, especially in cold climates. However, other studies conclude that the increase is marginal and often inconsequential. Another concern is that cool roofs can produce glare as the incident sunlight is reflected. This could adversely impact building users if the buildings with cool roofs are surrounded by taller structures with daytime occupancy, such as offices, which is an increasing reality in urban spaces. Lastly, we found examples of pilot projects and resources for cool roofs, but could not find reliable datasets for a comprehensive assessment of their current impact. Addressing such data gaps could help drive cool roofs research, integration into industry practices and building codes, and, ultimately, greater adoption.

Bamdad, K. (2023). Cool roofs: A climate change mitigation and adaptation strategy for residential buildings. Building and Environment, 236, Article 110271. Link to source: https://doi.org/10.1016/j.buildenv.2023.110271 

C40 Cities. (2015, January). NYC CoolRoofs. C40 Cities Leadership Group, Inc. Link to source: https://www.c40.org/case-studies/nyc-coolroofs/#:~:text=The%20NYC%20%C2%B0CoolRoofs%20program%2C%20launched%20in%202009%2C,(GHG)%20and%20also%20directly%20cooling%20the%20city.

Challenge Works. (n.d.). Million cool roofs challenge. Retrieved January 16, 2026, from Link to source: https://challengeworks.org/challenge-prizes/million-cool-roofs-challenge/

Cool Roof Paint. (2025, November). Cool roof vs conventional roof. Link to source: https://www.coolroofpaint.com/cool-roof-vs-conventional-roof/

Cool Roof Rating Council. (n.d.). Resources: What is a cool roof? Retrieved December 22, 2025, from Link to source: https://coolroofs.org/resources/what-is-a-cool-roof

Energy Star. (n.d.). Cool roofs. U.S. Environmental Protection Agency. Retrieved January 05, 2026, from Link to source: https://www.energystar.gov/products/cool-roofs

Heat Island Group. (n.d.). Cool science. Energy Technologies Area, Berkeley Lab.  Retrieved December 23, 2025, from Link to source: https://heatisland.lbl.gov/coolscience/cool-roofs

Hosseini, M., Lee, B., & Vakilinia, S. (2017). Energy performance of cool roofs under the impact of actual weather data. Energy and Buildings, 145, 284–292. Link to source: https://doi.org/10.1016/j.enbuild.2017.04.006

Market Reports World. (2025, December 29). Cool Roofs Market Size, Share, Growth, and Industry Analysis, By Type (PVC(Polyvinyl Chloride), EPDM(Rubber), TPO(Thermoplastic)), By Application (Residential Buildings, Non-Residential Buildings), Regional Insights and Forecast to 2033. Link to source: https://www.marketreportsworld.com/market-reports/cool-roofs-market-14716807

Nutkiewicz, A., Mastrucci, A., Rao, N. D., & Jain, R. K. (2022). Cool roofs can mitigate cooling energy demand for informal settlement dwellers. Renewable and Sustainable Energy Reviews, 159, Article 112183. Link to source: https://doi.org/10.1016/j.rser.2022.112183

Sustainable Energy For All. (2022). Chilling prospects 2022: The million cool roofs challenge. Link to source: https://www.seforall.org/data-stories/million-cool-roofs-challenge

Sustainable Energy For All. (2025, July). Chilling prospects: Tracking sustainable cooling for all 2025. Link to source: https://www.seforall.org/data-stories/chilling-prospects-2025

U.S. Department of Energy. (n.d.). Cool roofs. Retrieved December 22, 2025, from Link to source: https://www.energy.gov/energysaver/cool-roofs

U.S. Environmental Protection Agency. (2025, May 30). Using cool roofs to reduce heat islands. Link to source: https://www.epa.gov/heatislands/using-cool-roofs-reduce-heat-islands

Ürge-Vorsatz, D., Chatterjee, S., Cabeza, L. F., & Molnár, G. (2025). Global and regional estimation and evaluation of suitable roof area for solar and green roof applications. Developments in the Built Environment, 21, Article 100607. Link to source: https://doi.org/10.1016/j.dibe.2025.100607

Credits

Lead Fellow

  • Henry Igugu, Ph.D.

Internal Reviewer

  • Christina Swanson, Ph.D.

Action Word
Deploy
Solution Title
Cool Roofs
Classification
Worthwhile
Updated Date

Use Heat Pumps

Submitted by Drawdown Admin on
Sector
Buildings & Electricity
Mode
Cut Emissions
Cluster
Enhance Efficiency Shift Energy Sources
Image
Heat pumps
Coming Soon
Off
Summary

Heat pumps use electricity to efficiently move heat from one place to another. This solution focuses on the replacement of fossil fuel–based heating systems with electric heat pumps. Heat pumps are remarkably efficient because they collect heat from the outside air, ground, or water using a refrigerant and use a pump to move the heat into buildings to keep them warm in colder months. Heat pumps typically replace heating systems such as boilers, furnaces, and electric resistance heaters. Many will also replace air conditioners, because the same pump can move heat out of a building in warmer months. 

Heat stress
Income & work,Health
Description for Social and Search
Heat pumps are a Highly Recommended climate solution. They replace heating systems that burn fossil fuels; many can also provide cooling in hotter months.
Overview

Heat pumps use a refrigerant cycle to move heat. When the liquid refrigerant enters a low pressure environment, it absorbs heat from the surrounding air (air-source heat pumps), water, or ground (ground-source heat pumps) as it evaporates. When the refrigerant vapor is compressed, it condenses back into a liquid, releasing the stored heat into the building. By passing the refrigerant through this cycle, a heat pump can move heat from outside to inside a building. 

Absorbing heat from the outside gets more difficult as temperatures drop. However, modern cold-climate heat pumps are designed to work effectively at temperatures approaching –30 °C (–22 °F) (Gibb et al., 2023). The freezer in your home uses the same technology, moving heat out of the cold box into the warm room to keep your food frozen. In most systems, the refrigerant cycle in a heat pump can be reversed in warmer months, moving heat out of a building to ensure its occupants are comfortable year-round. 

Heat pumps are very efficient at using electricity for heating. This is because they move heat rather than generating heat (e.g., by combustion). For example, a heat pump may have a seasonal coefficient of performance (SCOP) of 3, meaning it can move an average of three units of heat energy for every unit of electrical energy that it consumes. Conventional combustion and electric resistance heaters cannot produce more than one unit of heat energy for every unit of fuel energy or electrical energy provided. 

Heat pump systems may be all-electric or hybrid, where a secondary fossil fuel-based heating system takes over in colder weather. 

A heat pump’s potential to reduce GHG emissions depends on the heating source it replaces and the emissions intensity of the electricity used to run it. When heat pumps replace fossil fuel-based heating, they displace the GHG emissions – primarily CO₂ – generated when the fuel is burned. When replacing electric resistance heaters, heat pumps reduce the GHG emissions from the electricity to power the system because heat pumps are much more energy efficient. As electrical grids decarbonize, the GHG emissions from operating heat pumps will decrease. 

All-electric heat pumps provide the most climate benefit because they can be powered with clean energy, but hybrid heat pumps also play an important emissions-reduction role. Hybrids consist of a smaller electric heat pump system that switches to fuel-based heating systems in colder weather. They may be attractive due to lower up-front costs and because they have lower peak power demand on cold days, but hybrids also have a smaller emissions impact. Our cost and emissions analyses assumed all-electric air-source heat pumps, while the data used in the adoption analysis included all types of heat pumps with the expectation that all-electric versions will dominate in the longer term. 

In this analysis, we calculated effectiveness and cost outcomes from specific countries with high heat-pump adoption (European countries, Canada, the United States, Japan, and China) to avoid comparing research studies that use different assumptions. The analysis used global assumptions for heating system efficiency: 90% for fueled systems (International Gas Union, 2019), 100% for electric resistance (U.S. Department of Energy [U.S. DOE], n.d.), and SCOP of 3 for heat pumps (Crownhart, 2023). We also assumed all existing fueled systems use natural gas, which is currently the dominant fossil fuel used for space heating globally (International Energy Agency [IEA], 2023b). The analysis did not include emissions or costs from cooling but did assume the heat pump is replacing both a heating and cooling system. 

The cost and effectiveness analyses focused on residential heating systems due to availability of data and also because large variations in the cost and size of commercial systems make it more challenging to estimate their global impacts. Commercial heating systems are typically larger than residential systems, and their emissions impacts are expected to be proportionally greater per unit. Cost savings may be different due the greater complexity of heating and cooling systems (Tejani & Toshniwal, 2023). Available data on heat pump adoption, on the other hand, typically include both residential and commercial units. Our adoption analysis therefore included both residential and commercial buildings, with greater adoption assumed in the residential sector. 

Air-Conditioning, Heating, and Refrigeration Institute. (2025). AHRI releases November 2024 U.S. heating and cooling equipment shipment data. Link to source: https://www.ahrinet.org/sites/default/files/Stat%20Release%20Nov%2024/November%202024%20Statistical%20Release.pdf 

Asahi, T. (2023, July 3). The role of heat pumps toward decarbonization [PowerPoint slides]. Japan Refrigeration and Air Conditioning Industry Association. Link to source: https://www.jraia.or.jp/english/relations/file/2023_July_OEWG45_JRAIA_side_event_Presentation_4.pdf 

Benz, S. A., & Burney, J. A. (2021). Widespread race and class disparities in surface urban heat extremes across the United States. Earth’s Future, 9(7), Article e2021EF002016. Link to source: https://doi.org/10.1029/2021EF002016 

Bloess, A., Schill, W.-P., & Zerrahn, A. (2018). Power-to-heat for renewable energy integration: A review of technologies, modeling approaches, and flexibility potentials. Applied Energy, 212, 1611–1626. Link to source: https://doi.org/10.1016/j.apenergy.2017.12.073 

Canadian Climate Institute. (2023). Heat pumps pay off [Report]. Link to source: https://climateinstitute.ca/wp-content/uploads/2023/09/Heat-Pumps-Pay-Off-Unlocking-lower-cost-heating-and-cooling-in-Canada-Canadian-Climate-Institute.pdf 

Carella, A., & D’Orazio, A. (2021). The heat pumps for better urban air quality. Sustainable Cities and Society, 75, Article 103314. Link to source: https://doi.org/10.1016/j.scs.2021.103314 

City of Vancouver. (n.d.). Climate change adaptation strategy [Report]. Retrieved September 2, 2025, from Link to source: https://vancouver.ca/files/cov/vancouver-climate-change-adaptation-strategy-2024-25.pdf 

Congedo, P. M., Baglivo, C., D’Agostino, D., & Mazzeo, D. (2023). The impact of climate change on air source heat pumps. Energy Conversion and Management, 276, Article 116554. Link to source: https://doi.org/10.1016/j.enconman.2022.116554 

Cooper, S. J. G., Hammond, G. P., McManus, M. C., & Pudjianto, D. (2016). Detailed simulation of electrical demands due to nationwide adoption of heat pumps, taking account of renewable generation and mitigation. IET Renewable Power Generation, 10(3), 380–387. Link to source: https://doi.org/10.1049/iet-rpg.2015.0127 

Crownhart, C. (2023, February 14). Everything you need to know about the wild world of heat pumps. MIT Technology Review. Link to source: https://www.technologyreview.com/2023/02/14/1068582/everything-you-need-to-know-about-heat-pumps/ 

Davis, L. W., & Hausman, C. (2022). Who will pay for legacy utility costs? Journal of the Association of Environmental and Resource Economists, 9(6), 1047-1085. Link to source: https://doi.org/10.1086/719793 

European Commission. (2022). REPowerEU: Joint European action for more affordable, secure and sustainable energy. Link to source: https://build-up.ec.europa.eu/en/resources-and-tools/publications/repowereu-joint-european-action-more-affordable-secure-and 

European Heat Pump Association. (2024, February 27). Heat pump sales fall by 5% while EU delays action. Link to source: https://www.ehpa.org/news-and-resources/news/heat-pump-sales-fall-by-5-while-eu-delays-action/ 

Gaur, A. S., Fitiwi, D. Z., & Curtis, J. (2021). Heat pumps and our low-carbon future: A comprehensive review. Energy Research & Social Science, 71, Article 101764. Link to source: https://doi.org/10.1016/j.erss.2020.101764 

Gibb, D., Rosenow, J., Lowes, R., & Hewitt, N. J. (2023). Coming in from the cold: Heat pump efficiency at low temperatures. Joule, 7(9), 1939–1942. Link to source: https://doi.org/10.1016/j.joule.2023.08.005 

Global Petrol Prices. (2024). Retail energy price data. Retrieved Feb 2, 2024, from Link to source: https://www.globalpetrolprices.com/ 

Intergovernmental Panel On Climate Change (Ed.). (2023). Climate change 2022: Mitigation of climate change. Working group III contribution to the sixth assessment report of the intergovernmental panel on climate change (1st ed.). Cambridge University Press. Link to source: https://doi.org/10.1017/9781009157926 

International Energy Agency. (2020). Sustainable recovery—World energy outlook special report (revised version). Link to source: https://iea.blob.core.windows.net/assets/c3de5e13-26e8-4e52-8a67-b97aba17f0a2/Sustainable_Recovery.pdf 

International Energy Agency. (2022). The future of heat pumps. Link to source: https://iea.blob.core.windows.net/assets/4713780d-c0ae-4686-8c9b-29e782452695/TheFutureofHeatPumps.pdf 

International Energy Agency. (2023a). Net zero roadmap: A global pathway to keep the 1.5 °C goal in reach—2023 update (revised version). Link to source: https://iea.blob.core.windows.net/assets/8ad619b9-17aa-473d-8a2f-4b90846f5c19/NetZeroRoadmap_AGlobalPathwaytoKeepthe1.5CGoalinReach-2023Update.pdf 

International Energy Agency. (2023b, June 15). Buildings-related energy demand for heating and share by fuel in the Net Zero Scenario 2022-2030. Link to source: https://www.iea.org/data-and-statistics/charts/buildings-related-energy-demand-for-heating-and-share-by-fuel-in-the-net-zero-scenario-2022-2030 

International Energy Agency. (2024). Clean energy market monitor. Link to source: https://iea.blob.core.windows.net/assets/d718c314-c916-47c9-a368-9f8bb38fd9d0/CleanEnergyMarketMonitorMarch2024.pdf 

International Energy Agency. (2025). Electricity 2025 (revised version). Link to source: https://iea.blob.core.windows.net/assets/0f028d5f-26b1-47ca-ad2a-5ca3103d070a/Electricity2025.pdf 

International Gas Union. (2019). Global gas insights 2019 gas & efficiency. Link to source: https://www.igu.org/advocacy/graphics-data/ggi-energy-efficiency 

International Renewable Energy Agency. (2022). Renewable solutions in end-uses: Heat pump costs and markets [Report]. Link to source: https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2022/Nov/IRENA_Heat_Pumps_Costs_Markets_2022.pdf 

International Renewable Energy Agency. (2024). World energy transitions outlook 2024: 1.5°C pathway [Report]. Link to source: https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2024/Nov/IRENA_World_energy_transitions_outlook_2024.pdf 

Jakob, M., Reiter, U., Krishnan, S., Louwen, A., & Junginger, M. (2020). Chapter 11 - Heating and cooling in the built environment. In M. Junginger & A. Louwen (Eds.), Technological learning in the transition to a low-carbon energy system (pp. 189–219). Academic Press. Link to source: https://doi.org/10.1016/B978-0-12-818762-3.00011-X  

Knobloch, F., Hanssen, S. V., Lam, A., Pollitt, H., Salas, P., Chewpreecha, U., Huijbregts, M. A. J., & Mercure, J.-F. (2020). Net emission reductions from electric cars and heat pumps in 59 world regions over time. Nature Sustainability, 3(6), 437–447. Link to source: https://doi.org/10.1038/s41893-020-0488-7 

Malmquist, A., Hjerpe, M., Glaas, E., Karlsson-Larsson, H., & Lassi, T. (2022). Elderly people’s perceptions of heat stress and adaptation to heat: An interview study. International Journal of Environmental Research and Public Health, 19(7), Article 3775. Link to source: https://doi.org/10.3390/ijerph19073775 

Mattiuzzi, C., & Lippi, G. (2020). Worldwide epidemiology of carbon monoxide poisoning. Human & Experimental Toxicology, 39(4), 387-392. Link to source: https://doi.org/10.1177/0960327119891214 

McDiarmid, H. (2023). An analysis of the impacts of all-electric heat pumps and peak mitigation technologies on peak power demand in Ontario [Report]. Ontario Clean Air Alliance. Link to source: https://www.cleanairalliance.org/wp-content/uploads/2023/12/Heat-Pump-Peak-Report-ONLINE-dec-11.pdf 

McDiarmid, H., & Parker, P. (2024). Retrofitting homes in Ontario entails significant embodied emissions: New policies needed. Climate Policy, 25(3), 388–400. Link to source: https://doi.org/10.1080/14693062.2024.2390520 

Renaldi, R., Hall, R., Jamasb, T., & Roskilly, A. P. (2021). Experience rates of low-carbon domestic heating technologies in the United Kingdom. Energy Policy, 156, Article 112387. Link to source: https://doi.org/10.1016/j.enpol.2021.112387 

Romanello, M., Walawender, M., Hsu, S.-C., Moskeland, A., Palmeiro-Silva, Y., Scamman, D., Ali, Z., Ameli, N., Angelova, D., Ayeb-Karlsson, S., Basart, S., Beagley, J., Beggs, P. J., Blanco-Villafuerte, L., Cai, W., Callaghan, M., Campbell-Lendrum, D., Chambers, J. D., Chicmana-Zapata, V., … Costello, A. (2024). The 2024 report of the Lancet Countdown on health and climate change: Facing record-breaking threats from delayed action. The Lancet, 404(10465), 1847–1896. Link to source: https://doi.org/10.1016/S0140-6736(24)01822-1 

Sandoval, N., Harris, C., Reyna, J. L., Fontanini, A. D., Liu, L., Stenger, K., White, P. R., & Landis, A. E. (2024). Achieving equitable space heating electrification: A case study of Los Angeles. Energy and Buildings, 317, Article 114422. Link to source: https://doi.org/10.1016/j.enbuild.2024.114422 

Sovacool, B. K., Evensen, D., Kwan, T. A., & Petit, V. (2023). Building a green future: Examining the job creation potential of electricity, heating, and storage in low-carbon buildings. The Electricity Journal, 36(5), Article 107274. Link to source: https://doi.org/10.1016/j.tej.2023.107274 

Tejani, A., & Toshniwal, V. (2023). Differential energy consumption patterns of HVAC systems in residential and commercial structures: A comparative study. International Journal of Advancements in Science & Technology, 1(3), 47–58. 

U.S. Department of Energy. (2022). Residential cold-climate heat pump technology challenge. Link to source: https://www.energy.gov/eere/buildings/articles/residential-cold-climate-heat-pump-technology-challenge-fact-sheet 

U.S. Department of Energy. (n.d.). Electric resistance heating. Retrieved September 2, 2025, from Link to source: https://www.energy.gov/energysaver/electric-resistance-heating 

U.S. Energy Information Administration. (2023). Updated buildings sector appliance and equipment costs and efficiencies [Report]. Link to source: https://www.eia.gov/analysis/studies/buildings/equipcosts/pdf/full.pdf 

Van Someren, C., Visser, M., & Slootweg, H. (2021). Impacts of electric heat pumps and rooftop solar panels on residential electricity distribution grids. 2021 IEEE PES Innovative Smart Grid Technologies Europe (ISGT Europe), 01–06. Link to source: https://doi.org/10.1109/ISGTEurope52324.2021.9640090 

Wilson, E. J. H., Munankarmi, P., Less, B. D., Reyna, J. L., & Rothgeb, S. (2024). Heat pumps for all? Distributions of the costs and benefits of residential air-source heat pumps in the United States. Joule, 8(4), 1000–1035. Link to source: https://doi.org/10.1016/j.joule.2024.01.022 

Zahiri, S., & Gupta, R. (2023). Examining the risk of summertime overheating in UK social housing dwellings retrofitted with heat pumps. Atmosphere, 14(11), Article 1617. Link to source: https://doi.org/10.3390/atmos14111617 

Zhang, Q., Zhang, L., Nie, J., & Li, Y. (2017). Techno-economic analysis of air source heat pump applied for space heating in northern China. Applied Energy, 207, 533–542. Link to source: https://doi.org/10.1016/j.apenergy.2017.06.083 

Zhou, M., Liu, H., Peng, L., Qin, Y., Chen, D., Zhang, L., & Mauzerall, D. L. (2022). Environmental benefits and household costs of clean heating options in northern China. Nature Sustainability, 5(4), 329–338. Link to source: https://doi.org/10.1038/s41893-021-00837-w 

Credits

Lead Fellow

  • Heather McDiarmid, Ph.D.

Contributors

  • Stephen Agyeman, Ph.D.

  • Ruthie Burrows, Ph.D.

  • James Gerber, Ph.D.

  • Sarah Gleeson, Ph.D.

  • Yusuf Jameel, Ph.D.

  • Daniel Jasper

  • Jason Lam

  • Cameron Roberts, Ph.D.

  • Alex Sweeney

  • Eric Wilczynski

Internal Reviewers

  • Aiyana Bodi

  • Hannah Henkin

  • Jason Lam

  • Zoltan Nagy, Ph.D.

  • Ted Otte

  • Amanda D. Smith, Ph.D.

Effectiveness

Our analysis showed that each all-electric residential heat pump for space heating reduces emissions by an average of 0.97 t CO₂‑eq /heat pump system/yr (20-yr and 100-yr basis, Table 1). 

Heat pumps reduce emissions by reducing the amount of fossil fuels burned for space heating or by reducing the use of less efficient electric resistance heating. Operating a heat pump generates no on-site emissions except refrigerant leaks, which are addressed by the Improve Refrigerant Management solution. Our analysis included the emissions from the electricity used to power heat pumps. Thus, the emissions reduction from heat pump adoption is expected to improve as electricity generation incorporates more renewable energy (Knobloch et al., 2020). 

There are significant regional differences in heat pump effectiveness due to the electricity mix, climate, and types of heating systems used today (Knobloch et al., 2020). The global average is weighted based on regional heating requirements and existing heating technologies. 

We did not quantify the reduction in pollutants such as nitrogen oxides, sulfur oxides, and particulate matter, which are released when fossil fuels are burned for space heating. We also refrained from estimating the global warming impacts of refrigerant leaks associated with the use of heat pumps, which is addressed by our Improve Refrigerant Management solution, or natural gas leaks associated with the use of fossil fuels for heating. 

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Table 1. Effectiveness at reducing emissions from space heating.

Unit: t CO₂‑eq/heat pump system/yr, 100-yr basis

Mean 0.97
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Cost

A residential air-source heat pump has a mean initial installed cost of US$6,800 and an estimated US$540/yr operational cost for heating. Over a 15-year lifespan, this results in a net cost of US$990/yr. A heat pump generally replaces both a heating and cooling system with a combined mean installed cost of US$5,300. Operating a baseline heating system costs US$830/yr (operational cooling cost was not included in this analysis). Over a 15-year lifespan, the baseline case has a net cost of US$1,180/yr. This results in a net US$190 savings for households that switch to a heat pump. This translates to US$200 savings/t CO₂‑eq reduced (Table 2).

These values include the average annual cost to operate the equipment for heating and the annualized up-front cost of a heat pump relative to both a heating and cooling system that it replaces. There can be significant variability in the up-front cost of equipment based on the type of heat pump installed, the size of the building, and the climate in which it is designed to operate. We assumed the cost to operate the equipment for cooling to be the same with heat pumps and the air conditioners they replace. 

There are significant regional differences in the operational cost of heating systems due to climate, utility rates, and the heating systems in use today. The global average outcomes described here are weighted averages from Europe, Canada, the United States, China, and Japan based on regional heating requirements and existing heating technologies. 

Utility cost estimates are from June 2023 (Global Petrol Prices, 2024) and may vary substantially over time due to factors such as volatile fossil fuel prices, changing carbon prices, and heat pump incentives. Additional installation costs, such as upgrades to electrical systems, ductwork, or radiators, are not included. 

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Table 2. Cost per unit climate impact. Negative values reflect cost savings.

Unit: 2023 US$/t CO₂‑eq , 100-yr basis

Mean –200
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Methods and Supporting Data

Methods and Supporting Data

Learning Curve

Insufficient data exist to quantify the learning curve for heat pumps. 

The cost of installing a heat pump includes both equipment costs and the labor cost of installation. According to the U.S. Energy Information Administration ([U.S. EIA] 2023), retail equipment costs are 60–80% of the total installed cost of residential air-source heat pumps (central and ductless). 

Equipment costs can decrease with economies of scale and as local markets mature, but may be confounded by technological advances as well as equipment and/or refrigerant regulations that can also increase costs (IEA, 2022). European estimated learning rates for heat pump equipment costs range from 3.3% for ground-source heat pumps (Renaldi et al., 2021) to 18% for air-source heat pumps (Jakob et al., 2020). Ease and cost of installation is a research and development goal for manufacturers (IEA, 2022). 

The installed cost is also affected by rising labor costs and projected labor shortages (IEA, 2022). Renaldi et al. (2021) showed negative learning rates for the total installed costs in the United Kingdom due to increasing installation costs: –2.3% and –0.8% for air-source and ground-source heat pumps, respectively.

Heat pump manufacturer efforts to improve the performance of the technology may impact learning curves as well. In North America, the Residential Heat Pump Technology Challenge has supported the development of heat pumps with improved cold-climate performance (U.S. DOE, 2022). 

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Speed of Action

Speed of action refers to how quickly a climate solution physically affects the atmosphere after it is deployed. This is different from speed of deployment, which is the pace at which solutions are adopted.

At Project Drawdown, we define the speed of action for each climate solution as emergency brake, gradual, or delayed.

Use Heat Pumps is a GRADUAL climate solution. It has a steady, linear impact on the atmosphere. The cumulative effect over time builds as a straight line.

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Caveats

Heat pumps can increase demand for electricity and can therefore increase demand for fossil fuel-based power generation. In areas where power generation relies heavily on fossil fuels, heat pumps may generate more emissions than gas heating systems. As the electricity sector adopts more renewables and phases out fossil fuel-based generation, the emissions impact of heat pumps will decrease. Once a building has been designed or retrofitted to accommodate a heat pump it is likely that new heat pumps will be installed at the end of equipment life, perpetuating the benefit.

Efforts are underway to retrofit buildings by improving insulation, air-sealing, and upgrading windows. When done alongside heat pump adoption, retrofits can reduce the size of heat pump needed and increase total energy, emissions, and cost savings. 

As heat pump adoption grows, so too will the manufacture of refrigerants, some of which have high global warming potentials when they escape to the atmosphere. See Deploy Alternative Refrigerants and Improve Refrigerant Management solutions for more on accelerating change in this sector.

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Current Adoption

Our analysis suggests that 130 million heat pumps for heating are currently in operation primarily based on data in Europe, Canada, the United States, China, and Japan (Table 3). These include both all-electric heat pumps and hybrid heat pumps. The IEA (2023a) estimated that 12% of global space heating demand was met by heat pumps in 2022. 

This value is based on market reports and national data sources plus IEA (2022) estimates of total GW of installed capacity. To convert installed capacity to the number of heat pumps, we used the median from the range of suggested average capacities (7.5 kW for Europe and North America, 4 kW in Japan and China, 5 kW global average). In Japan, where heat pump units typically heat only one room, we assumed 2.4 units per heat pump (International Renewable Energy Agency [IRENA], 2022).

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Table 3. Current heat pump adoption level (2020–2022).

Unit: Heat pump systems in operation

Mean 130,000,000
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Adoption Trend

Our estimates put the median adoption trend at 17 million new all-electric and hybrid heat pumps in operation per year (Table 4). This analysis is based on product shipment data (used as a proxy for installed heat pumps), market reports, national statistics, and IEA data for growth in installed capacity. For the IEA data (2010–2023), we assumed a global average of 5 kW of heat capacity per heat pump unit (IEA, 2024).

Shipment and market analysis reports consistently show growing markets for heat pumps in much of the world (Asahi, 2023; European Heat Pump Association, 2024; IEA, 2024). In the United States, shipments of heat pumps have outnumbered gas furnaces since at least 2022 (Air-Conditioning, Heating, and Refrigeration Institute, 2025).

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Table 4. Heat pump adoption trend (2010–2023).

Unit: Heat pump systems in operation/yr

25th percentile 12,000,000
Mean 15,000,000
Median (50th percentile) 17,000,000
75th percentile 18,000,000
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Adoption Ceiling

Our adoption ceiling is set at 1.200 billion heat pumps for space heating by 2050 (Table 5), most of which are expected to be in residential buildings. This is based on the IEA’s Net Zero Roadmap projection that heat pumps will represent 6,500 GW of heating capacity globally by 2050, covering 55% of space heating demand (IEA, 2023a). Our adoption ceiling assumes all-electric heat pumps cover all space heating demand. 

We assumed that average heat pump sizes (capacities) will increase over time as heat pumps cover a greater portion of a building’s heating load and as more commercial buildings with larger heating loads install heat pumps. Using a global average of 10 kW per heat pump, the IEA projections imply 650 million heat pumps will be in operation by 2050 with the technical adoption ceiling for 1,200 million heat pumps if all heating demand were met by heat pumps.

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Table 5. Heat pump adoption ceiling: upper limit for adoption level.

Unit: Heat pump systems in operation by 2050

Mean 1,200,000,000
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Achievable Adoption

We estimate the achievable range for heat pump adoption to be 600–960 million heat pumps in operation by 2050 (Table 6).

Most existing space heating systems will be replaced at least once between now and 2050 because this equipment typically has lifetimes of 15–30 years (U.S. EIA, 2023). Policies that encourage high efficiency heat pumps alongside insulation upgrades have the potential to provide lifetime savings, greater comfort, and energy efficiency benefits (Wilson et al., 2024). Given the available timelines and potential benefits, near full adoption is technically feasible. 

We have set the Achievable – High heat pump adoption at 80% of the adoption ceiling to account for systems that are difficult to electrify due to very cold climates, policy, economic barriers, and grid constraints. This high achievable value assumes that some systems may be replaced before their end of life to meet climate and/or financial goals. 

We have set the Achievable – Low heat pump adoption at 50% of the adoption ceiling. This is roughly consistent with the current adoption trend continuing out to 2050. 

Our heat pump units adopted include both all-electric and hybrid heat pumps. This analysis assumes that hybrid heat pumps will become less common as fuels are phased out and that all-electric heat pumps will dominate by 2050. 

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Table 6. Range of achievable adoption levels.

Unit: Heat pump systems installed

Current adoption 130,000,000
Achievable – low 600,000,000
Achievable – high 960,000,000
Adoption ceiling 1,200,000,000
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Our estimates show the global impact of existing heat pumps for space heating to be a reduction of 0.13 Gt CO₂‑eq/yr (100- and 20-yr basis) based on current adoption and today’s electricity grid emissions (Table 7). Because electricity grid emissions are decreasing for each kWh of electricity generated (IEA, 2025), the actual impact will be greater than our estimates when future electricity generation emissions are lower.

For the adoption ceiling, assuming heat pumps supply all of the IEA’s projected global heating demand in 2050 (IEA, 2023a), 1.2 Gt CO₂‑eq/yr (100- and 20-yr basis) could be avoided per year with today’s electricity grid emissions.

A high-end achievable target is 80% of the adoption ceiling, accounting for systems that might continue to use fossil fuels for heating due to factors such as cold climates, economic barriers, and grid constraints. This would result in avoiding 0.93 Gt CO₂‑eq/yr (100- and 20-yr basis) with today’s electricity grid emissions. 

A low-end achievable target is 50% of the adoption ceiling, roughly equivalent to heat pump adoption continuing at today’s rate. This would result in avoiding 0.58 Gt CO₂‑eq/yr (100- and 20-yr basis) with today’s electricity grid emissions. 

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Table 7. Climate impact at different levels of heat pump systems adoption.

Unit: Gt CO₂‑eq/yr, 100-yr basis

Current adoption 0.13
Achievable – low 0.58
Achievable – high 0.93
Adoption ceiling 1.2
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Additional Benefits

Heat Stress

Heat waves and extreme heat are becoming increasingly significant factors of morbidity and mortality worldwide (Romanello et al., 2024). Some buildings that replace heating systems with heat pumps will gain access to cooling (Congedo et al., 2023; Wilson et al., 2024; Zhang et al., 2017). This can provide protection from heat stress in regions experiencing increasingly hotter summers (where air conditioning was not previously necessary) and for populations that are vulnerable to heat stress, such as the elderly (Malmquist et al., 2022). Some jurisdictions incentivize heat pumps for this reason. For example, the United Kingdom plans to install 600,000 heat pumps by 2028 (Zahiri & Gupta, 2023), and local climate adaptation plans in Canada recommend the installation of heat pumps to provide space cooling that can reduce morbidity and mortality during heat waves (Canadian Climate Institute, 2023; City of Vancouver, n.d.). Because exposure to extreme heat is disproportionately higher for minority communities – particularly in urban environments – access to cooling has important implications for environmental justice (Benz & Burney, 2021). 

Income and Work

Installing heat pumps can lead to greater household savings on electricity. Research has shown that across the United States, heat pumps can reduce electricity bills for 49 million homes with an average savings of US$350–600 per year, depending on the efficiency of the heat pump (Wilson et al., 2024). Wilson et al. (2024) found that higher efficiency heat pumps could be cost-effective for about 65 million households in the United States. Heat pumps also create jobs (Sovacool et al., 2023). In its post-COVID-19 recovery plan, the IEA (2020) estimated that every US$1 million investment in heat pumps could generate 9.1 new jobs and reduce 0.8 jobs in the fossil fuel industry. About half of the new jobs will be in manufacturing, with the remaining distributed between installation and maintenance.

Health

Burning fossil fuels for heating directly emits health-harming particulates and can generate carbon monoxide. Replacing fossil gas heating with heat pumps can reduce air pollution (Carella & D’Orazio, 2021) and contribute to improving health outcomes (Zhou et al., 2022). A study in China showed that as the power grid moves to incorporate renewable energy, the air quality and health benefits of heat pumps will increasingly outweigh the benefits of gas heaters (Zhou et al., 2022). The risk of carbon monoxide poisoning also decreases in buildings that switch from fuel-burning space heating to heat pumps. In buildings that burn fuels for applications such as space heating, carbon monoxide can pose serious health risks, including poisoning and death (Mattiuzzi & Lippi, 2020). 

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Risks

Heat pumps contain refrigerants that often have high global warming potentials. Refrigerant leaks can occur during installation, operation, and end of life (McDiarmid & Parker, 2024). As more heat pumps are adopted, there is a risk of increased emissions from refrigerant leaks during operation as well as refrigerant release at the end of equipment life. Alternate refrigerants with lower global warming potentials are being phased in due to an international agreement to reduce hydrofluorocarbons, including many refrigerants (Kigali Amendment). 

Higher rates of heat pump installation will require upscaling heat pump manufacturing and training, plus certification of skilled labor to install them. Skilled labor shortages are already creating bottlenecks for heat pump adoption in some countries, some of which can be met by reskilling other heating technicians (IEA, 2022).

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Interactions with Other Solutions

Reinforcing

Advancements in heat pump technology will support the development and adoption of heat pump technology for industrial applications.

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The increased adoption of heat pumps will increase the market for alternative refrigerants and refrigerant management.

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Competing

Heat pumps reduce the emissions from heating and cooling buildings. This reduces the effectiveness of technologies that reduce heating and/or cooling demands.

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Adoption of heat pumps for space heating is likely to generate seasonal peaks in power demand during cold days that may require building out extra generating capacity that decrease grid efficiency (Bloess et al., 2018). Heat pumps can compete with electric cars for power during peak times (Van Someren et al., 2021).

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Dashboard

Solution Basics

heat pump systems

t CO₂-eq (100-yr)/unit/yr
0.95
units
Current 1.3×10⁸ 06.0×10⁸9.6×10⁸
Achievable (Low to High)

Climate Impact

Gt CO₂-eq (100-yr)/yr
Current 0.13 0.580.93
US$ per t CO₂-eq
-200
Gradual

CO₂ , CH₄, N₂O, BC

Trade-offs

Enhanced grid infrastructure will be required to support widespread building electrification and the greater demand for electricity, especially on cold days when heat pumps are less efficient at moving heat (Cooper et al., 2016). Demand-side management, thermal storage, home batteries, bidirectional chargers, and greater adoption of ground-source heat pumps can all help to reduce this increased demand (Cooper et al., 2016; McDiarmid, 2023).

In general, heat pumps have higher up-front costs than do fueled alternatives but will save a building owner money over the lifetime of the system. This can create economic barriers to accessing the benefits of heat pumps, with low-income homeowners and renters who pay for their utilities being particularly vulnerable to being left behind in the transition (Sandoval et al., 2024). Equity advocates are also concerned that the cost of maintaining gas and other fossil fuel infrastructure may increasingly fall on lower-income building owners who struggle to afford the upfront cost of electrifying with heat pumps (Davis & Hausman, 2022). 

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°C days
015,000

Space heating demand (18 °C basis)

Heating degree days are a measure of total space-heating demand to maintain an indoor temperature above 18 °C. Here we show annual average heating degree days for the decade ending in 2025.

Copernicus Climate Change Service. (2023). ERA5 hourly data on single levels from 1940 to present [Data set]. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). Retrieved January 13, 2026 from Link to source: https://doi.org/10.24381/cds.adbb2d47     

Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz‐Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmins, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., … Thépaut, J. N. (2020). The ERA5 global reanalysis. Quarterly Journal of the Royal Meteorological Society, 146(730), 1999–2049. Link to source: https://doi.org/10.1002/qj.3803  

°C days
015,000

Space heating demand (18 °C basis)

Heating degree days are a measure of total space-heating demand to maintain an indoor temperature above 18 °C. Here we show annual average heating degree days for the decade ending in 2025.

Copernicus Climate Change Service. (2023). ERA5 hourly data on single levels from 1940 to present [Data set]. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). Retrieved January 13, 2026 from Link to source: https://doi.org/10.24381/cds.adbb2d47     

Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz‐Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmins, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., … Thépaut, J. N. (2020). The ERA5 global reanalysis. Quarterly Journal of the Royal Meteorological Society, 146(730), 1999–2049. Link to source: https://doi.org/10.1002/qj.3803  

Maps Introduction

In this solution, heat pumps replace space-heating options that rely on fossil fuels. This primarily applies to North America, Asia, and Europe. Limited data are available for some regions, so this analysis focuses on European countries, Canada, the United States, Japan and China. 

The effectiveness of heat pumps at reducing GHG emissions is influenced by the heating needs of the region and the generation mix of the electricity grid. Areas with higher heating needs will generally show greater emissions reduction because more energy is needed to keep buildings warm. However, this is partially offset because heat pumps are less energy efficient on colder days. The local electricity grid mix matters because heat pumps are powered by electricity. Given the same outside temperature, regions with a largely emissions-free grid (e.g., France or Canada) will have higher emissions impacts from heat pump adoption than areas where electricity is  largely generated from fossil fuels (e.g., China). The type of heat pumps (all-electric vs. hybrid) best suited to each region depends on technological and economic factors.

Action Word
Use
Solution Title
Heat Pumps
Classification
Highly Recommended
Lawmakers and Policymakers
  • Introduce zero-carbon ready building codes, clearly designating heat pumps as the default for all new buildings.
  • Incentivize purchases with grants, loans, or tax rebates.
  • Increasing training and support for heat pump installers.
  • Expand the electrical grid and increase renewable energy generation.
  • Streamline permitting processes.
  • Incentivize complementary solutions such as better insulation, thermal storage, and air sealing.
  • Institute a clean heat standard (similar to a renewable energy standard) with a well-defined implementation timeline.
  • Launch performance labels for heating technology.
  • Roll out new energy efficiency programs.

Further information:

Practitioners
  • Commit to zero-carbon construction, clearly designating heat pumps as the default for all new buildings.
  • Increase the available workforce by encouraging trade organizations to promote career and workforce development programs.
  • Design heat pumps that are simpler, faster, and cheaper to install.
  • Educate customers on the benefits and train them on usage.
  • Connect with users and early adopters to understand and adapt to consumer sentiment.
  • Create appealing incentives and financing programs.
  • Partner with builders and developers to improve product adoption and increase market demand for heat pumps.

Further information:

Business Leaders
  • Commit to zero-carbon construction, clearly designating heat pumps as the default for all new buildings.
  • Deploy heat pumps in all owned and operated facilities.
  • Encourage building owners and managers to switch to heat pumps in leased facilities.
  • Promote the benefits of heat pumps and share government incentives with leased facilities and networks.
  • Encourage employees to reduce emissions at home by providing educational resources on the benefits of domestic heat pumps.

Further information:

Nonprofit Leaders
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Deploy heat pumps in owned and operated facilities.
  • Encourage building owners and managers to switch to heat pumps in leased facilities.
  • Educate businesses and communities on the benefits of installing heat pumps and any tax incentives in their region.
  • Advocate to policymakers for improved policies and incentives.
  • Educate community leaders on the need for adoption.

Further information:

Investors
  • Commit to only finance zero-carbon construction with clear requirements for heat pumps as the default for all new development investments.
  • Deploy capital to efforts that improve heat pump performance and reduce material, installation, and maintenance costs.
  • Explore investment opportunities that address supply chain concerns.
  • Consider investments that mitigate non-manufacturing barriers to scaling.
  • Finance heat pump installations via low-interest loans.

Further information:

Philanthropists and International Aid Agencies
  • Directly distribute heat pumps, prioritizing locations where heat pumps maximize emissions reductions, and improve housing affordability.
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Fund R&D efforts and competitions to improve technology, reduce costs, and address supply chain concerns.
  • Support consumer advocacy and education campaigns on heat pumps and how to maximize regulatory incentives.
  • Support training or incentive programs for distributors and installers.

Further information:

Thought Leaders
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Highlight the need to transition away from fossil-fuel-fired heating.
  • Educate the public on the benefits of heat pumps and how they work.
  • Provide case studies that present successes and lessons learned.
  • Increase consumer comfort by including heat pumps in communication content on topics such as home remodeling and construction, technology, health, self-sufficiency, and personal finance.
  • Provide up-to-date user information on available models.

Further information:

Technologists and Researchers
  • Identify safe, cost-effective, and suitable alternative refrigerants.
  • Design systems that require less refrigerant.
  • Work to increase the longevity of heat pumps.
  • Improve heat pumps’ efficiency and capacity at low temperatures as well as their ability to deliver higher temperature heat.
  • Research external social factors critical to adoption.
  • Identify appropriate methods for recycling and disposing of heat pumps and responsibly recovering their refrigerant chemicals at the end of the product life cycle. 

Further information:

Communities, Households, and Individuals
  • Install heat pumps when possible and encourage local heating, ventilation, and air conditioning (HVAC) retailers and installers to sell services and equipment.
  • Increase consumer comfort by sharing your experience and tips for troubleshooting technologies.
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Build support networks for new users and connect to explore innovations.
  • Encourage your property management company, employers, and government officials to accelerate adoption. 

Further information:

Sources
Evidence Base

Consensus of effectiveness in reducing GHG emissions: High

Electric heat pumps are generally viewed as the primary strategy for reducing GHG emissions from buildings. The Intergovernmental Panel on Climate Change ([IPCC] 2023) noted that heat pumps drive electrification in buildings and help decrease emissions. The European Commission (2022) claimed that heat pumps are an essential way of decreasing reliance on gas in heating while increasing the use of renewable energy in the heating sector. The IEA (2022) reported that heat pumps powered by electricity generated with renewable energy “are the central technology in the global transition to secure and sustainable heating.” IRENA (2024) claimed heat pumps in buildings “will play a crucial role in reducing reliance on fossil fuels.” 

In one of the largest scientific reviews on the topic, Gaur et al. (2021) concluded that heat pumps “have the potential to play a substantial role in the transition to low carbon heating,” and noted that emissions impacts of heat pumps are dependent on the type of heat pump technology, their location, and the electricity grid mix. Knobloch et al. (2020) studied 59 world regions and found that electrification of the heating sector via heat pumps will reduce emissions in most world regions where they are adopted.

The results presented in this document summarize findings from 46 reports, reviews and meta-analyses and 13 original studies reflecting current evidence from 30 countries, primarily European countries, Canada, the United States, Japan, and China. We recognize this limited geographic and technology scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions and in the commercial sector.

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Automate Building Systems

Submitted by Drawdown Admin on
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Buildings & Electricity
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Cut Emissions
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Enhance Efficiency
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The Automate Building Systems solution is coming soon.
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Solution Title
Building Systems
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Highly Recommended
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Improve Windows & Glass

Submitted by Drawdown Admin on
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Summary

We define Improve Windows & Glass as reducing the heat transferred through typical windows used in residential and nonresidential buildings by improving the thermal insulation capacity of the glass. Windows typically constitute a small portion of a building envelope but account for a substantial portion of the heat transferred (gained or lost) between the indoor space and the external environment. Using double-glazed rather than single-glazed windows cuts GHG emissions by reducing the energy required to heat or cool a building’s interior and improves the thermal comfort of its occupants.

Income & work,Health
Air quality
Description for Social and Search
Improve Windows & Glass is a Highly Recommended climate solution. Upgrading single-glazed windows to double-glazing saves money, improves comfort, and cuts GHG emissions.
Overview

Windows represent 15–40% of a building's total envelope surface area (Shah et al., 2024). A significant amount of the heat transmitted through the building envelope occurs via windows (Basok et al., 2022; Cuce & Riffat, 2015), and the uncontrolled flow of heat due to poor thermal insulation capabilities of windows and glass can generally increase the energy required for heating or cooling indoor spaces by 30–50% (Arasteh et al., 2006; Balali et al., 2023; Gustavsen et al., 2011). Improving windows and glass helps reduce heat gain in warm climates and heat loss in cold climates, thereby reducing the energy required to thermally condition indoor spaces and cutting energy-related emissions while improving occupant comfort.

Operating buildings accounts for approximately 30% of global energy consumption (Delmastro & Chen, 2023). The International Energy Agency (IEA, 2023e) stated that heating indoor spaces accounted for more than 41 EJ of energy in 2022 (an equivalent of about 11,400 TWh). This energy is mainly fossil fuel–based (oil, natural gas, and coal), but also includes electricity, modern bioenergy, and solar thermal (IEA, 2023b; 2023e) (Figure 1). Space cooling is largely achieved through air conditioners. In 2022, cooling buildings used approximately 2,111 TWh (an equivalent of about 8 EJ) (IEA, 2023d; Ritchie, 2024). According to the IEA (2018), annual space-cooling energy consumption in 2016 (2,020 TWh) was more than three times its levels in 1990. Considering the mix of energy sources (IEA, 2023b), this solution potentially cuts CO₂, methane, and nitrous oxide emissions and reduces black carbon and F-gas refrigerant emissions from operating heating and cooling systems (Richardson, 2024; Pistochini et al., 2022).

Figure 1. Energy used in buildings globally largely originates from fossil fuel–based sources.

Source: International Energy Agency. (2023b, June 15). Energy consumption in buildings by fuel in the net zero scenario, 2010-2030. 

The properties of a window determine the rate of heat transfer (i.e., its thermal transmittance or U-value) and thus its efficacy at decreasing the flow of heat between the indoors and outdoors (Aguilar-Santana, 2020; Saint-Gobain, 2018). Window types such as double-glazed, double-glazed with low emissivity (low-e) coating, or triple-glazed (Figure 2) perform better than single-glazed windows due to their lower U-values (Aguilar-Santana et al., 2020; Li et al., 2023; Salazar et al., 2024). In more resourced countries or regions such as the United States, Canada, and the European Union, a minimum of double glazing is considered standard practice, accounting for a growing share of the number of windows installed or sold annually (Hermelink et al., 2017; Janssens, 2021). However, the minimum glazing U-value standards set by building energy regulations in most low- and middle-income countries, where the bulk of new construction occurs (IEA, 2023c), often do not mandate the use of better performing windows in buildings (Gaum, 2023). 

Improve Windows and Glass assesses the impact of retrofitting single-glazed windows in the current (2022) global building stock, focusing on scaling up the use of double glazing as the minimum. Retrofitting extends the lifespan of building components and helps these buildings remain in use. The U-value of 2.7 W/m2K we used for double glazing during our analysis also includes other double pane window types with similar U-values such as secondary glazing where a second window is added to the outside of the existing one.

Figure 2. Multiple-glazed windows reduce heat transmission better than single glazed windows and so create less demand for GHG-producing fuels. Modified from Aguilar-Santana et al. (2020) and Moghaddam et al. (2023).

A description of different glazing types.

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Aguilar-Santana, J. L., Jarimi, H., Velasco-Carrasco, M., & Riffat, S. (2020). Review on window-glazing technologies and future prospects. International Journal of Low-Carbon Technologies, 15(1), 112–120. Link to source: https://doi.org/10.1093/ijlct/ctz032

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Balasbaneh, A. T., Yeoh, D., Ramli, M. Z., & Valdi, M. H. T. (2022). Different alternative retrofit to improving the sustainability of building in tropical climate: Multi-criteria decision-making. Environmental Science and Pollution Research, 29(27), 41669–41683. Link to source: https://doi.org/10.1007/s11356-022-18647-8

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Calautit, J. K., Sun, H., Li, J., Dik, A., & Mohammadi, M. (2025). Keeping it simple: Field testing and techno-economic assessment of a low-cost secondary quad glazing for enhanced energy efficiency in buildings [Corrected proof]. Energy and Built Environment. Link to source: https://doi.org/10.1016/j.enbenv.2025.03.004

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Duan, Q., Hinkle, L., Wang, J., Zhang, E., & Memari, A. (2021). Condensation effects on energy performance of building window systems. Energy Reports, 7, 7345–7357. Link to source: https://doi.org/10.1016/j.egyr.2021.10.096

Es-sakali, N., Kaitouni, S. I., Laasri, I. A., Mghazli, M. O., Cherkaoui, M., & Pfafferott, J. (2022). Assessment of the energy efficiency for a building energy model using different glazing windows in a semi-arid climate. Proceedings of the 13th International Renewable Energy Congress (IREC), 1–5. Link to source: https://doi.org/10.1109/IREC56325.2022.10001934

Gasparotto, J., & Da Boit Martinello, K. (2021). Coal as an energy source and its impacts on human health. Energy Geoscience, 2(2), 113–120. Link to source: https://doi.org/10.1016/j.engeos.2020.07.003

Gaum, T. (2023). Building energy codes in the Global South: Comparing selected variables to develop a decision-making model to address climate-change guidelines [Spreadsheet]. SLIM3. Link to source: https://docs.google.com/spreadsheets/d/1aP4zaeDvfwSI-3Abuj8Z_VUUEHJzjMZS/edit?gid=988383392#gid=988383392

Gaum, T., & Laubscher, J. (2022). Building energy codes: Reviewing the status of implementation strategies in the Global South. International Journal of Built Environment and Sustainability, 9(1), 39–53. Link to source: https://doi.org/10.11113/ijbes.v9.n1.871

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Gomaa, M. M., Abdallah, A. S. H., Aloshan, M. A., & Ragab, A. (2025). A comparative analysis of advanced glazing technologies for energy-efficient buildings in Jeddah city, Saudi Arabia. Buildings, 15(9), Article 1477. Link to source: https://doi.org/10.3390/buildings15091477

Gustavsen, A., Grynning, S., Arasteh, D., Jelle, B. P., & Goudey, H. (2011). Key elements of and material performance targets for highly insulating window frames. Energy and Buildings, 43(10), 2583–2594. Link to source: https://doi.org/10.1016/j.enbuild.2011.05.010

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Hermelink, A., von Manteuffel, B., & Grözinger, J. (2017). Minimum performance requirements for window replacement in the residential sector [Report]. ECOFYS. Link to source: https://glassforeurope.com/wp-content/uploads/2018/04/Minimum-performance-requirements-for-window-replacement-in-the-residential-sector.pdf

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International Energy Agency. (2022a, September 1). Global buildings sector CO2 emissions and floor area in the net zero scenario, 2020-2050. Link to source: https://www.iea.org/data-and-statistics/charts/global-buildings-sector-co2-emissions-and-floor-area-in-the-net-zero-scenario-2020-2050

International Energy Agency. (2022b). Renovation of near 20% of existing building stock to zero-carbon-ready by 2030 is ambitious but necessary. Link to source: https://www.iea.org/reports/renovation-of-near-20-of-existing-building-stock-to-zero-carbon-ready-by-2030-is-ambitious-but-necessary

International Energy Agency. (2023b, June 15). Energy consumption in buildings by fuel in the net zero scenario, 2010-2030. Link to source: https://www.iea.org/data-and-statistics/charts/energy-consumption-in-buildings-by-fuel-in-the-net-zero-scenario-2010-2030-2

International Energy Agency. (2023c, June 15). Global floor area and buildings energy intensity in the net zero scenario, 2010-2030. Link to source: https://www.iea.org/data-and-statistics/charts/global-floor-area-and-buildings-energy-intensity-in-the-net-zero-scenario-2010-2030

International Energy Agency. (2023d). Space cooling: Net zero emissions guide. Link to source: https://www.iea.org/reports/space-cooling-2

International Energy Agency. (2023e). Space heating: Net zero emissions guide. Link to source: https://www.iea.org/reports/space-heating

International Energy Agency. (2023f, July 11). Total floor area by use in the net zero scenario, 2010-2030. Link to source: https://www.iea.org/data-and-statistics/charts/total-floor-area-by-use-in-the-net-zero-scenario-2010-2030-2

International Energy Agency. (2024). World energy balances. Link to source: https://www.iea.org/data-and-statistics/data-product/world-energy-balances

Janssens, C. (2021, September 27). Minimum energy performance requirements for window replacement in the 28 EU member states. Glassonweb. Link to source: https://www.glassonweb.com/article/minimum-energy-performance-requirements-window-replacement-28-eu-member-states 

Karabay, H., & Arici, M. (2012). Multiple pane window applications in various climatic regions of Turkey. Energy and Buildings, 45, 67–71. Link to source: https://doi.org/10.1016/j.enbuild.2011.10.020

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Moghaddam, S. A., Serra, C., Gameiro da Silva, M., & Simões, N. (2023). Comprehensive review and analysis of glazing systems towards nearly zero-energy buildings: Energy performance, thermal comfort, cost-effectiveness, and environmental impact perspectives. Energies, 16(17), Article 6283. Link to source: https://doi.org/10.3390/en16176283

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Credits

Lead Fellow

  • Henry Igugu, Ph.D.

Contributors

  • Ruthie Burrows, Ph.D.

  • James Gerber, Ph.D.

  • Daniel Jasper

  • Alex Sweeney

Internal Reviewers

  • Sarah Gleeson, Ph.D.

  • Heather McDiarmid, Ph.D.

  • Amanda D. Smith, Ph.D.

Effectiveness

Each 1 m2 of single-glazed window glass in buildings that is upgraded to double glazing has the potential to cut GHG emissions by approximately 0.07 t CO₂‑eq/yr (20-yr and 100-yr basis).

To determine the solution’s effectiveness (Table 1), we evaluated the emissions cut from reducing space heating and space cooling. Since studies often capture different U-value ratings for similar window glass, we weighted the energy saved (kWh/yr) from improving the glass using consistent U-values for the baseline and solution (see Figure 2). Thereafter, we weighted the energy impact by the total area of glass substituted (m2) to determine the savings intensity (kWh/m2/yr) and multiplied the estimate by emission intensities of heating and cooling fuels based on the IEA’s world energy balances data (IEA, 2024).

This solution cuts CO₂, methane, and nitrous oxide emissions by reducing the amount of fossil fuels used for heating and for producing electricity used for cooling. The analysis includes studies from countries representative of heating-dominated and cooling-dominated climates such as the United States (Calautit et al., 2025) and Malaysia (Balasbaneh et al., 2022), respectively. Notably, the solution is also effective in other climates (Magraoui et al., 2025).

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Table 1. Effectiveness at reducing emissions.

Unit: t CO₂‑eq /m2/yr, 100-yr basis

25th percentile 0.043
Mean 0.095
Median (50th percentile) 0.065
75th percentile 0.13
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Cost

Our estimate of the cost per unit climate impact (Table 2) indicates that replacing single-glazed windows with double-glazed windows in buildings globally results in considerable savings of approximately US$123/t CO₂‑eq.

We found that the solution’s initial cost varies considerably, from about US$31/m2 in Malaysia (Balasbaneh et al., 2022) to US$257–684/m2 in France (Harkouss et al., 2018), highlighting regional price differences that could affect adoption. Ultimately, we chose an initial cost of approximately US$144/m2 for double glazing. Using the cost of single glazing we found in studies from different regions (Aruta et al., 2025; Krarti & Ihm, 2016), our analysis determined a baseline initial cost of approximately US$35/m2. While the solution cost is more than four times the baseline, less energy is used for space heating or cooling, reducing the annual operating cost from US$23/m2 to approximately US$12/m2. After amortizing the initial cost over 30 years, the solution resulted in a net savings of US$8/m2/yr, compared with the baseline.

During our analysis, we normalized the initial cost by the baseline and solution U-value (see Figure 2) to ensure consistency. We assumed the initial cost includes the glass component alone, but some of our sources were ambiguous about the scope of the investment and may have also included frames and installation costs. To determine the cost per adoption unit, we weighted the amount of energy consumed for heating and cooling in each data source using the total area of windows upgraded in the respective case study buildings. The analysis does not include revenues because building owners typically do not generate any revenue from window glass installed. 

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Table 2. Cost per unit of climate impact.

Unit: 2023 US$/t CO₂‑eq , 100-yr basis

Median -123
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Methods and Supporting Data

Methods and Supporting Data

Learning Curve

We found no definitive data on the solution’s learning rate. While the adoption of double glazing grows, some studies have reported rising cost of glass in recent periods (MLI Building Products, 2023). In an assessment of regional float glass price trends, Procurement Resource (n.d.) argued that rising material, energy, and labor costs amid other economic pressures are driving up the cost of glass. Since modern windows are often made using float glass (Asahi India Glass Ltd., 2025), the initial cost could become more expensive.

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Speed of Action

Speed of action refers to how quickly a climate solution physically affects the atmosphere after it is deployed. This is different from speed of deployment, which is the pace at which solutions are adopted.

At Project Drawdown, we define the speed of action for each climate solution as emergency brake, gradual, or delayed.

Improve Windows and Glass is a GRADUAL climate solution. It has a steady, linear impact on the atmosphere.

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Caveats

Our analysis for this solution focused on the U-value of the glass component alone. It did not include other parameters such as the material type of the window frames or coatings on windows, though these also impact space heating and cooling energy use (Owolabi et al., 2023). We ensured that the data used in our analysis aligned with our approach (i.e., indicated the impact of solely substituting double-glazed or better glass for single-glazed). Due to limited data, we assumed that current adoption in LMICs is 5%. The adoption scenarios and climate impact may be influenced if the actual percentage is higher or lower.

A window’s orientation impacts the solar heat gain. Thus, the influence of upgrading to double-glazing on heating or cooling loads is affected by window placement. We found limited data that incorporates orientation and did not account for this difference.

Recently, some studies have indicated concerns about the payback period of upgrading to double glazing for building owners (Calautit et al., 2025), especially in LMICs, where higher initial costs could be a barrier. Creative initiatives such as incentive schemes can improve the payback period (Aruta et al., 2025). 

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Current Adoption

To determine the current adoption of double-glazed windows, we first estimated the total amount of window glass installed in buildings by applying window-to-floor area ratios from studies to the currently existing 198.1 billion m2 residential and 54.6 billion m2 nonresidential building floor space (IEA, 2023f). This yielded approximately 23.3 billion m2 and 42.2 billion m2 of window glass installed in high-income countries (HICs) and low- and middle-income countries (LMICs), respectively (IEA, 2023c). 

We found limited data for the proportion of minimum double-glazed windows in HICs. The U.S. Energy Information Administration (U.S. EIA, 2023) reported that 80 million housing units (65%) in the U.S. have double-glazed windows installed. Percentages reported for other countries include 88% of housing units in the United Kingdom (Department for Levelling Up, Housing and Communities, 2023), 90% in Canada (Natural Resources Canada, n.d.), and 15% in Australia (Paarhammer, n.d.). Using these percentages, we estimated a 76% (median) solution adoption rate in HICs.

Since we found no definitive data for the solution’s adoption in LMICs, and considering a few LMICs have building energy codes that either mandate or encourage the use of higher performing windows (Gaum, 2023; Gaum & Laubscher, 2022), we assumed that double-glazed windows represent a conservative underestimate of 5%. 

All told, we estimate that as of 2022, installed double-glazed windows in buildings cover roughly 19.9 billion m2 globally (Table 3).

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Table 3. Current (2022) adoption level.

Unit: m2 windows minimum double-glazed

25th percentile 14,300,000,000
Mean 17,100,000,000
Median (50th percentile) 19,900,000,000
75th percentile 22,700,000,000
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Adoption Trend

According to the Department for Levelling Up, Housing and Communities (2023), the percentage of UK homes that have double-glazed windows increased by 9% between 2012 and 2022. Similarly, adoption grew by about 6% in five years (2015–2020) in the United States (U.S. EIA, 2018). Using these countries as representatives, this growth translates to approximately 438–448 million m2 of double-glazed or better windows being added every year in HICs.

We found limited data for adoption trends in LMICs. Based on our assumption for the current adoption in LMICs, we assumed that the percentage adoption of double-glazed windows grew by 4% over 10 years (2012–2022). This assumption, which is likely a conservative underestimate, translates to an annual addition of about 178 million m2/yr of double glazing.

Based on these findings, we estimate that the adoption of double glazing or better windows has grown globally by nearly 622 million m2 annually (Table 4).

Historically, the bulk of the solution’s adoption has occurred in HICs. However, the Global Alliance for Buildings and Construction, IEA, and the United Nations Environment Programme (UNEP) emphasize that adopting double-glazed windows is a necessary sustainability strategy for the building sector, especially in Africa and LMICs (GlobalABC/IEA/UNEP, 2020). This indicates considerable potential for scaling the solution, with 76% of the global building sector’s growth in the past 12 years occurring in LMICs (IEA, 2023f), where there has been less adoption of double glazing or better windows.

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Table 4. 2010–2022 adoption trend.

Unit: m2/yr

25th percentile 620,000,000
Mean 622,000,000
Median (50th percentile) 622,000,000
75th percentile 624,000,000
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Adoption Ceiling

We estimated an adoption ceiling (Table 5) of approximately 46.7 billion m2 of double-glazed windows globally. For this adoption scenario, 90% and 61% of window glass that existed in 2022 will be retrofitted to double-glazed or better by 2050 in buildings in HICs and buildings in LMICs, respectively.

In our analysis, we used the current double-glazed windows ratio of 90% in Canada (Natural Resources Canada, n.d) as a benchmark for the building sector’s adoption ceiling in HICs. For buildings in LMICs, we used the IEA’s recommended 2%/yr retrofit rate (IEA, 2022b) over 28 years (2022–2050). This estimated 56% growth was added to the current adoption of 5% to determine the region’s adoption ceiling. The analysis results in about 21 billion m2 and 26 billion m2 of double-glazed windows installed in buildings in HICs and LMICs, respectively.

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Table 5. Adoption ceiling.

Unit: m2 windows minimum double-glazed

Estimate 46,700,000,000
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Achievable Adoption

Our analysis estimated a low achievable adoption of approximately 32.9 billion m2 of double-glazed or better windows installed in buildings globally (Table 6). For this scenario, we estimate that the percentage of windows that were at minimum double-glazed as of 2022 in buildings in HICs (76%) and buildings in LMICs (5%) grows to 81% and 33%, respectively.

Under the high achievable scenario, 86% of window glass in buildings in HICs and 47% of window glass in buildings in LMICs is at minimum double-glazed. This translates to a total of nearly 40.0 billion m2 of double glazing or better installed by 2050.

The achievable adoption scenarios are largely driven by the growth that is possible in LMICs. We assumed a retrofit rate of 1%/yr for the Achievable – Low scenario, which is the current global retrofit rate in the building industry (IEA, 2022b); for Achievable – High, we used 1.5%/yr. We also assumed that the current (2022) building stock will still be in use by 2050.

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Table 6. Range of achievable adoption levels.

Unit: m2 windows minimum double-glazed

Current adoption 19,900,000,000
Achievable – low 32,900,000,000
Achievable – high 40,000,000,000
Adoption ceiling 46,700,000,000
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The current adoption of double-glazed windows in buildings reduces global GHG emissions by approximately 1.3 Gt CO₂‑eq/yr on a 100-yr and 20-yr basis (Table 7). If the low achievable adoption scenario is reached, this solution could potentially cut about 2.1 Gt CO₂‑eq/yr (100-yr and 20-yr basis). The high achievable scenario would decrease global emissions 2.6 Gt CO₂‑eq/yr year (100-yr and 20-yr basis). We estimated that the adoption ceiling could avoid up to 3.0 Gt CO₂‑eq/yr of emissions on a 100-yr basis (3.1 Gt CO₂‑eq/yr, 20-yr basis).

This solution only accounts for the impact of retrofitting the building stock that exists as of 2022. However, the current global built floor area (252.7 billion m2) is projected to grow by an additional 183 billion m2, by 2050 (IEA, 2022a; 2023b). This means a possible addition of 1.6 billion m2 of new window glass every year, indicating that the potential for scaling the climate impact exists.

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Table 7. Climate impact at different levels of adoption.

Unit: Gt CO₂‑eq/yr, 100-yr basis

Current adoption 1.3
Achievable – low 2.1
Achievable – high 2.6
Adoption ceiling 3.0
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Additional Benefits

Income and Work

While multi-glazed windows are often more of an initial investment than single-pane windows, improved performance of these windows is associated with more energy and cost savings (Menzies & Wherrett, 2005). Regional climates often affect the most appropriate window type and the amount of savings (Karabay & Arici, 2012). In residential buildings, double-glazed windows can add value to homes and increase property values (Aroul & Hansz, 2011). 

Health

Reductions in air pollution due to lower heating and cooling demand decrease exposures to pollutants such as mercury and fine particulate matter generated from fossil fuel–based power plants, improving the health of nearby communities (U.S. Environmental Protection Agency [EPA], 2025). These pollutants have been linked to increased morbidity from cardiovascular and respiratory disease, asthma, infections, and cancer (Gasparotto & Martinello, 2021) and to increased risk of mortality (Henneman et al., 2023). 

Better-performing windows can benefit health through improved thermal comfort (Bulut et al., 2021). When combined with other measures to reduce cooling loads, double-glazed windows can help with the risk of indoor heat stress (Ren et al., 2014). Improved windows may also reduce condensation and mold growth in buildings (Lozinsky et al., 2025). Residents of households with double-glazed windows have reported improvements in noise insulation after retrofitting single-pane windows (Bulut et al., 2021). 

Air Quality

Higher-performing glass can reduce air pollution by lowering gas and electricity demand for heating and cooling, which can decrease pollutants such as CO₂, nitrogen oxides, methane, mercury, and fine particulate matter generated from fossil fuel–based power plants (U.S. EPA, 2025).

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Risks

Faulty installation could compromise the expected benefits of double glazing. It could also lead to condensation on the inner pane if the sealant deteriorates, affecting visibility, aesthetics, and performance and resulting in a potential shorter lifespan than single glazing (Duan et al., 2021; Likins-White, 2023). Additional costs may be incurred when attempting to secure adequate expertise and equipment to ensure proper handling and installation (DIY Double Glaze, n.d.). Depending on the extent of the retrofits, this may drive up construction costs, which is a concern for building developers. However, it also represents opportunities to improve available technical expertise in regions where these services are unavailable or underdeveloped.

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Interactions with Other Solutions

Reinforcing

Improve Windows and Glass reduces the amount of space heating and cooling required. This may reduce the required size and complexity of heating and cooling systems, making them more economically accessible.

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Upgrading window glass can motivate building owners to improve other elements of the building envelope. This could improve the cost efficiency of the upgrades when approached holistically. 

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Competing

The potential climate impact of deploying these solutions could be lower due to the reduced amount of space heating and cooling required in buildings from improving window glass.

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Dashboard

Solution Basics

m2 windows minimum double-glazed

t CO₂-eq (100-yr)/unit/yr
00.040.065median
units
Current 1.99×10¹⁰ 03.29×10¹⁰4.0×10¹⁰
Achievable (Low to High)

Climate Impact

Gt CO₂-eq (100-yr)/yr
Current 1.3 2.12.6
US$ per t CO₂-eq
-123
Gradual

CO₂ , CH₄, N₂O, BC

Trade-offs

Manufacturing double-glazed or better windows generates more industrial sector emissions than does manufacturing single-glazed windows due to the additional materials used. However, life-cycle analysis studies such as Balasbaneh et al. (2022) compared different glazing options ranging from single to triple glazing and determined that the emissions reduced by using better windows outweighs the embodied emissions. Although it is outside the scope of this solution, window frames account for as much as 46–80% of a window's embodied emissions, especially when using conventional window frame materials such as polyvinyl chloride and aluminum (Saadatian et al., 2021). Despite the higher embodied emissions, the emissions reductions from implementing the solution are substantial.

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°C days
015,000

Space heating demand (18 °C basis)

Heating degree days are a measure of total space-heating demand to maintain an indoor temperature above 18 °C. Here we show annual average heating degree days for the decade ending in 2025.

Copernicus Climate Change Service. (2023). ERA5 hourly data on single levels from 1940 to present [Data set]. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). Retrieved January 13, 2026 from Link to source: https://doi.org/10.24381/cds.adbb2d47 

Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz‐Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmins, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., … Thépaut, J. N. (2020). The ERA5 global reanalysis. Quarterly Journal of the Royal Meteorological Society, 146(730), 1999–2049. Link to source: https://doi.org/10.1002/qj.3803

°C days
015,000

Space heating demand (18 °C basis)

Heating degree days are a measure of total space-heating demand to maintain an indoor temperature above 18 °C. Here we show annual average heating degree days for the decade ending in 2025.

Copernicus Climate Change Service. (2023). ERA5 hourly data on single levels from 1940 to present [Data set]. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). Retrieved January 13, 2026 from Link to source: https://doi.org/10.24381/cds.adbb2d47 

Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz‐Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmins, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., … Thépaut, J. N. (2020). The ERA5 global reanalysis. Quarterly Journal of the Royal Meteorological Society, 146(730), 1999–2049. Link to source: https://doi.org/10.1002/qj.3803

Maps Introduction

The effectiveness of replacing single-glazed windows in buildings to mitigate climate change varies depending on how buildings are heated and the emissions intensity of electricity used for cooling in each region. We used regional data for the share of heating fuel in buildings (IEA, 2023a). For the electricity used to provide cooling in buildings, we used a global estimate for emission intensity. While the need for heating has historically outweighed the need for cooling, global trends show a steady increase in cooling degree days and a decline in heating degree days, even in colder climates (Eurostat, 2024; U.S. Environmental Protection Agency (U.S. EPA), 2024). Nonetheless, studies such as Kennard et al. (2022) claim that population growth, especially in cooling-dominated climates, will drive rising cooling demand. This growth could potentially drive up the amount of electricity needed to air condition buildings (Waite et al. 2017).

Building energy efficiency codes, especially mandatory regulations, could help drive the adoption of the solution via higher U-value requirements for windows and glass, particularly in low- and middle-income countries (Gaum, 2023). Our analysis also shows that the cost of double-glazed windows varies by country and region.

Action Word
Improve
Solution Title
Windows & Glass
Classification
Highly Recommended
Lawmakers and Policymakers
  • Set clear and measurable targets for building efficiency, emissions reduction, and the deployment of improved windows.
  • Enact holistic policy plans and building codes to reduce GHG emissions from buildings through improved windows and framing systems.
  • Set public procurement standards for windows and glass, using double-glazed windows, at minimum, for public buildings.
  • Amend building codes to include minimum requirements based on window performance; gradually increase the standards over time if necessary.
  • Periodically update codes, policies, and public guidance to keep pace with research and development.
  • Make double-glazed windows the minimum standard option through a range of policy interventions, including regulations, subsidies, and educational programs where relevant; extend incentives to high performing secondary-, double- or triple-glazed windows, if relevant.
  • Offer financial incentives such as subsidies, tax credits, and grants for consumers, manufacturers, start-ups, and improved window installers.
  • Ensure financial incentives reach, and offer additional incentives for, low- and middle-income communities.
  • Ensure financial incentives cover both new installations and retrofits.
  • Create financial disincentives such as higher taxes and fines for lower performing windows.
  • Subsidize workforce or skills development and/or work with businesses to identify gaps and needs such as technical knowledge or the advantages of new technology.
  • Invest in research and development to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Create green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.
  • Offer educational resources, one-stop shops for windows, and demonstrations for installation and retrofits; offer tours of model builds that feature improved windows for commercial and private developers, highlighting the cost savings, and environmental benefits.

Further information:

Practitioners
  • Finance or develop only new construction and retrofits that use improved windows and other low-carbon practices.
  • Take advantage of financial incentives such as subsidies, tax credits, and grants for installing improved windows.
  • Seek or negotiate preferential loan agreements for developers using improved windows and other climate-friendly practices.
  • Use double-glazed windows as the most basic standard and offer a variety of better-performing options such as triple-glazed.
  • Work with designers and architects who integrate efficient windows and other efficient materials into their designs.
  • Integrate improved window designs into construction databases, including listing prices, thermal insulation properties, and environmental benefits.
  • Advocate for financial incentives, improved building codes, and educational programs advancing the use of improved windows.
  • Use educational resources, one-stop shops for retrofitting and weatherization, installation demonstrations, and tours of model builds.
  • Conduct research to improve the manufacturing, adoption, supply chain access, and circularity of windows.
  • Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for improving windows.

Further information:

Business Leaders
  • Finance only new construction and retrofits that use improved windows and other low-carbon practices.
  • Expand product lines to include improved window designs.
  • Integrate improved window designs into construction databases, listing prices, thermal insulation properties, and environmental benefits.
  • Invest in research and development to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Advocate for financial incentives, improved building codes, and educational programs advancing the use of improved windows.
  • Join green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.
  • Create long-term purchasing agreements with improved window manufacturers to support stable demand and improve economies of scale.
  • Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Nonprofit Leaders
  • Finance or develop only new construction and retrofits that use improved windows and other low-carbon practices.
  • Advocate for clear and measurable public targets for building efficiency, emissions reduction, and deployment of improved windows.
  • Advocate for holistic policy plans and building codes to reduce GHG emissions from buildings that include improved windows and framing systems.
  • Advocate for financial incentives, improved building codes, and educational programs advancing the use of improved windows.
  • Conduct research to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Work with businesses for workforce or skills development.
  • Offer educational resources, one-stop shops for windows, and demonstrations for installation and retrofits; offer tours of model builds that feature improved windows for commercial and private developers, highlighting the cost savings and environmental benefits.
  • Create, join, or administer green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Investors
  • Finance only new construction and retrofits that use improved windows and other low-carbon practices.
  • Invest in research and development and start-ups to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Issue green bonds to invest in projects that use improved windows and integrate other climate-friendly construction practices.
  • Offer preferential loan agreements for developers using improved windows and other climate-friendly practices.
  • Join green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Philanthropists and International Aid Agencies
  • Finance only new construction and retrofits that use improved windows and other low-carbon practices.
  • Offer grants for developers using improved windows and other climate-friendly practices.
  • Create financing programs for private construction in low-income or under-resourced communities requiring the use of improved windows.
  • Advocate for clear and measurable public targets for building efficiency, emissions reduction, and the deployment of improved windows.
  • Advocate for holistic policy plans and building codes to reduce GHG emissions from buildings that include improved windows and framing systems.
  • Advocate for financial incentives, improved building codes, and educational programs for improved windows.
  • Fund research to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Offer educational resources, one-stop shops for retrofitting and weatherization, installation demonstrations, and tours of model builds for commercial and private developers, highlighting the cost savings and environmental benefits.
  • Create, join, or administer green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Thought Leaders
  • Advocate for clear and measurable public targets for building efficiency, emissions reduction, and the deployment of improved windows.
  • Advocate for holistic policy plans and building codes to reduce GHG emissions from buildings that include improved windows and framing systems.
  • Advocate for financial incentives, improved building codes, and educational programs for improved windows.
  • Conduct research to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Contract with businesses for workforce or skills development.
  • Offer or support educational resources, one-stop shops for retrofitting and weatherization, installation demonstrations, and tours of model builds for commercial and private developers, highlighting the cost savings and environmental benefits of improved windows.
  • Create, join, or administer green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Technologists and Researchers
  • Research and develop high-performance window technologies such as vacuum glazing, aerogel applications, potential integration of solar photovoltaic glass, and the use of unconventional gases to fill multi-pane windows and improve performance.
  • Create improved alternatives to common practices for air and vapor sealing.
  • Find alternative materials for spacers with reduced thermal conductivity in double- and triple-glazed windows.
  • Research and develop alternative window frame designs to improve thermal performance, structural insulating materials, and improve ease of installation (e.g., out-of-the-box window installation kits).
  • Improve efficiency of the window manufacturing process, supply chain access, and the circular economy of glass.

Further information:

Communities, Households, and Individuals
  • Finance or develop only new construction and retrofits that use improved windows and other low-carbon practices.
  • Take advantage of financial incentives such as subsidies, tax credits, and grants for installing improved windows.
  • Advocate for clear and measurable public targets for building efficiency, emissions reduction, and the deployment of improved windows.
  • Advocate for holistic policy plans and building codes to reduce GHG emissions from buildings that include improved windows and framing systems.
  • Advocate for financial incentives, improved building codes, and educational programs for improved windows.
  • Organize local “green home tours” and open houses to showcase climate-friendly builds, fostering demand by highlighting cost savings and environmental benefits of improved windows.
  • Capture community feedback and share it with local policymakers to address barriers such as permitting logistics or up-front costs, helping to shape policies that drive adoption.
  • Create, join, or administer green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Sources
Evidence Base

Consensus of effectiveness in reducing GHG emissions: High

Improving windows and glass helps optimize the amount of heating required in buildings by reducing heat loss. Calautit et al. (2025) reported that energy used for heating in a United Kingdom residence dropped nearly 23% after reducing the glass U-value from 5.6 W/m2K to 2.8 W/m2K. Using the same building parameters, the study tested the impact of reducing the U-value by 1.35 W/m2K in the climatic conditions of Netherlands, Japan, United States, Sweden and Australia. The outcomes were similar, with about a 10–12% reduction in heating loads (Calautit et al., 2025). The results from Yuk et al. (2024), Magraoui et al. (2025), and Ahmed et al. (2025) further support these findings. 

Similarly, the solution reduces heat gained from the outdoors into buildings, thereby cutting cooling loads. Gomaa et al. (2025) reported that energy use in a Saudi Arabian residence was reduced by 1,265 kWh/yr (49%) after improving the glass U-value from 5.6 to 0.9 W/m2K (84%). Es-sakali et al. (2022) recorded 36% less electricity consumed after reducing the U-value by 1.44 W/m2K in Morocco’s climate.

The results presented in this document summarize findings from 10 original studies reflecting current evidence from 13 countries. We recognize this limited geographic scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions. The studies we found used simulations to assess the impact of retrofitting windows due to the inherent difficulty of real-world experiments. However, we used studies that include field measurements and calibration of the building simulations to validate their models.

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Updated Date

Improve Building Envelopes

Submitted by Drawdown Admin on
Sector
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Mode
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Cluster
Enhance Efficiency
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Improve building envelopes
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Methods and Supporting Data

Methods and Supporting Data

Action Word
Improve
Solution Title
Building Envelopes
Classification
Highly Recommended
Updated Date

Improve District Heating: Buildings

Submitted by Drawdown Admin on
Sector
Buildings & Electricity
Mode
Cut Emissions
Cluster
Enhance Efficiency
Image
District heating facility
Coming Soon
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Methods and Supporting Data

Methods and Supporting Data

Action Word
Improve
Solution Title
District Heating: Buildings
Classification
Highly Recommended
Updated Date
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