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Use Smart & Programmable Thermostats

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Hand pointing to smart thermostat on the wall

We define Use Smart & Programmable Thermostats as reducing energy use and associated GHG emissions from heating and cooling by automatically making adjustments to the set temperature of a residential building. Smart thermostats can be remotely controlled and can adjust indoor temperature settings in response to learned occupancy patterns, while programmable thermostats require a user to manually program a temperature schedule.

Last updated August 27, 2026

Solution Basics

smart or programmable thermostat programmed to adjust temperatures for the purposes of saving energy

t CO₂-eq (100-yr)/unit/yr
0.23
units
Current 1.4×10⁸ 02.9×10⁸5.1×10⁸
Achievable (Low to High)

Climate Impact

Gt CO₂-eq (100-yr)/yr
Current 0.033 0.0650.12
US$ per t CO₂-eq
-370
Gradual

CO₂ , CH₄, N₂O

Solution Basics

smart or programmable thermostat programmed to adjust temperatures

t CO₂-eq (100-yr)/unit/yr
0.091
units
Current 3.0×10⁷ 01.9×10⁸5.1×10⁸
Achievable (Low to High)

Climate Impact

Gt CO₂-eq (100-yr)/yr
Current 0.003 0.0170.046
US$ per t CO₂-eq
-230
Gradual

CO₂ , CH₄, N₂O

Additional Benefits

183,187
    183
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  • 185
  • 186
  • 187
  • 188
194

Overview

Residential buildings directly and indirectly generate GHG emissions through the fuels and electricity used for heating, cooling, and other functions. These emissions accounted for 12.5% of global emissions in 2021 (Ge et al., 2026). Heating is the largest residential source of operational emissions, with cooling being another major contributor (Energy Transitions Commission, 2025).

Smart and programmable thermostats reduce energy use by allowing temperatures to drift when occupants are away or asleep and restoring optimal temperatures in anticipation of occupants returning or waking. Since heating systems often rely on burning fossil fuels for heat (International Energy Agency [IEA], 2023), the emissions affected are primarily CO₂. Similarly, the emissions affected when cooling demands are reduced are primarily CO₂ from the electricity generated to power heat pumps and air conditioners. 

The amount of CO₂ saved with smart and programmable thermostats can vary substantially with occupant behavior, set points, occupancy levels, and climate (Pritoni et al., 2015; Stopps & Touchie, 2021). We used the minimum performance standard for Energy Star–certified smart thermostats, namely 8% run-time reduction for heating and 10% for cooling (Energy Star, 2017), with run time being used as a proxy for energy savings. This is a conservative value; many studies have measured or modeled higher savings (Alhamayani et al., 2021; Pang et al., 2021). 

Owning a smart or programmable thermostat does not guarantee it will be used to adjust temperatures to save energy (Pritoni et al., 2015; Stopps & Touchie, 2021). For example, while 53% of U.S. homes own a smart or programmable thermostat, only 16% report using a smart or programmable thermostat to automatically adjust temperatures (U.S. Energy Information Administration [U.S. EIA], 2023a). We also assumed that households that do not have a smart or programmable thermostat are not manually adjusting temperatures to save energy. 

As societies electrify, smart and programmable thermostats may play an increasingly important role in shifting demand away from grid peak periods (Stopps & Touchie, 2022). This can reduce emissions even further because grids often depend more on fossil fuel peaker plants during these times. This analysis does not include such emissions reductions. 

Impact Calculator

Adjust effectiveness and adoption using range sliders to see resulting climate impact potential.

Effectiveness

0.23
t CO2-eq (100-yr)/smart or programmable thermostat programmed to adjust temperatures for the sake of saving energy/yr

Adoption

1.4×10⁸
smart or programmable thermostat programmed to adjust temperatures for the purposes of saving energy
Low
2.9×10⁸
High
5.1×10⁸
1.4×10⁸
current
Achievable Range

Climate Impact

0.03
Gt CO₂-eq/yr (100-yr)
05
which is the equivalent of
0.05%
of global emissions
Adjust effectiveness and adoption using range sliders to see resulting climate impact potential.

Effectiveness

0.091
t CO2-eq (100-yr)/unit/yr

Adoption

3.0×10⁷
smart or programmable thermostat programmed to adjust temperatures
Low
1.9×10⁸
High
5.1×10⁸
3.0×10⁷
current
Achievable Range

Climate Impact

0.00
Gt CO₂-eq/yr (100-yr)
05
which is the equivalent of
0.00%
of global emissions

The Details

Current State

For heating, 0.23 t CO₂‑eq/yr (20- and 100-yr basis) is reduced for every smart or programmable thermostat in use (Table 1a). This is a weighted global average based on the proportion of homes that use different sources of energy for space heating and assumes an 8% reduction in heating energy with a smart or programmable thermostat (Energy Star, 2017). 

For cooling, 0.091 t CO₂‑eq/yr is reduced for every smart or programmable thermostat in use (100-year basis, 0.092 t CO₂‑eq/yr on a 20-yr basis) (Table 1b). This is a weighted global average based on regional electricity demand for space cooling and regional electricity grid emission factors. The analysis assumes a 10% reduction in cooling energy with a smart or programmable thermostat (Energy Star, 2017).

The effectiveness of smart or programmable thermostats at reducing emissions will vary based on total heating and cooling demand. This is a function of climate and building performance as well as occupant behaviors (Hendron et al., 2021). Occupants may, for example, differ in how much they allow temperatures to drift while away or at night, how frequently overrides are used, and the schedules on which programming is based (Hendron et al., 2021).

Table 1. Effectiveness at reducing emissions from heating and cooling.

Unit: t CO₂‑eq /smart or programmable thermostat used to save energy for heating/yr, 100-yr basis

Mean 0.23

Unit: t CO₂‑eq )/smart or programmable thermostat used to save energy on cooling/yr, 100-yr basis

Mean 0.091

A smart or programmable thermostat for heating will save an average household US$370/t CO₂‑eq reduced (Table 2a). A smart or programmable thermostat for heating has an average initial cost of US$74, and households that adopt and use these thermostats to save on energy will spend on average US$89 less per year on heating. Assuming a 15-year lifespan (EGIA Contractor University, 2025), this results in a net US$84/yr savings.

We assumed that half of adopting households worldwide purchase a smart or programmable thermostat to use in their homes and the other half already own a smart or programmable thermostat and start using them to save energy with programmed setbacks. This is consistent with US statistics that show 55% of households with heating have a smart or programmable thermostat but only 16% use one to adjust heating temperatures, with most using one set temperature most of the time (U.S. EIA, 2023a). 

A smart or programmable thermostat for cooling will save a household US$230/t CO₂‑eq reduced (see Table 2b). The average initial cost for a smart or programmable thermostat for cooling is US$58, and will save a household an average of US$25/yr on cooling. Assuming a 15-year lifespan, this results in a net US$21/yr savings for the household.

For cooling, the initial cost assumes one-third of homes purchase a smart or programmable thermostat for a central air conditioning system, one-third purchase such a thermostat for a window or portable air conditioner, and one third use an existing smart or programmable thermostat but change behaviors to start using the programming feature. Similar to heating, 60% of U.S. households with cooling have a smart or programmable thermostat but only 15% use one to adjust cooling temperatures (U.S. EIA, 2023b). 

Table 2. Cost per unit climate impact for heating and cooling. Negative values reflect cost savings.

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

Mean -370

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

Mean -230

Insufficient data exist to quantify the learning curve for smart or programmable thermostats. 

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 Smart & Programmable Thermostats is a GRADUAL climate solution. It has a steady, linear impact on the atmosphere. The cumulative effect over time builds as a straight line.

Adoption

We estimated that 140 million households worldwide use smart or programmable thermostats to save energy for heating (Table 3a) and 30 million use them to save energy for cooling (Table 3b). 

The climate impact of this solution depends on households not only adopting the technology, but also using it to regularly adjust temperatures with the goal of saving energy. Where only adoption values exist, we assumed use patterns are similar to those in the United States, where 25–29% of households that own a smart or programmable thermostat are using the programming feature (U.S. EIA, 2023a; U.S. EIA, 2023b).

For adoption, we estimated the number of households with smart or programmable thermostats in high-income countries separately from low- and middle-income countries and combined them to get a global total. In each case, we applied the average smart or programmable thermostat use rate for the group of countries to their estimated number of households that require heating or cooling. 

These estimates are based on data from seven studies covering different geographies and spanning 2017–2025. 

Table 3. Current adoption level (2025).

Unit: smart or programmable thermostats used for the purposes of saving energy on heating 

Total 140,000,000

Unit: smart or programmable thermostats used for the purposes of saving energy on cooling

Total 30,000,000

We estimate that globally, each year 1.4 million households start using smart or programmable thermostats to save on heating (Table 4a) and 0.60 million households start using them to save on cooling (Table 4b).

These data are based on surveys for heating and cooling covering 2015–2020 in the United States (U.S. EIA 2018b, 2018a, 2023b, 2023a) and 2007–2023 in Canada (Statistics Canada, 2025). Due to lack of data, we were not able to estimate adoption trends for low- and middle-income countries, and assumed the trend is negligible. 

Table 4. Current adoption trend (2007–2023).

Unit: smart or programmable thermostats put to use for saving energy on heating/yr 

Total 1,400,000

Unit: smart or programmable thermostats put to use for saving energy on cooling/yr

Total 600,000

If every household that currently relies on heating were to adopt and use smart or programmable thermostats to save energy, the total adoption would be 650 million households (Table 5a). This is based on the IEA’s estimate that 40% of households worldwide require space heating (World Bank, n.d.), combined with regional population estimates (United Nations, 2024), and estimates for household sizes by region (Pew Research Center, 2019).

Similarly for cooling, if every household that currently uses air conditioning were to adopt and use smart or programmable thermostats to save energy, the total adoption would be 580 million households (Table 5b). This is based on Falchetta et al.’s (2024) estimate that 35% of households worldwide currently have space cooling, combined with population and household size estimates (Pew Research Center, 2019; United Nations, 2024). This analysis does not reflect anticipated growing demand for space cooling with rising populations, rising affluence in low- and middle-income countries, and rising temperatures (Falchetta et al., 2024).

Table 5. Adoption ceiling: upper limit for adoption level.

Unit: smart or programmable thermostats put to use for saving energy on heating

Total 650,000,000

Unit: smart or programmable thermostats put to use for saving energy on cooling

Total 580,000,000

For heating, we estimate that use of smart or programmable thermostats to save on energy could reach 290 to 510 million households globally (Table 6a). In high income countries, this assumes 65–100% of households with heating needs adopt and use thermostats to save energy. At the low end, this represents the reported rate of regular setback use for heating homes in the state of New York (Lockheed Martin Energy, 2017), and we assume all heating households could program thermostats to save energy at the high end. In low and middle income countries, we assume 16–48% of households with heating needs adopt and use smart or programmable thermostats to save energy. This is based on today’s estimated smart and programmable thermostat adoption and use rate in the United States and Canada respectively (Statistics Canada, 2025; U.S. EIA, 2023a).

For cooling, we estimate that use of smart or programmable thermostats to save on energy could reach 190–510 million households globally (see Table 6b). In high income countries, this assumes 75–100% of households with cooling systems use thermostats to save energy for cooling. At the low end, this represents the reported rate of regular setback use for cooling homes in the state of New York (Lockheed Martin Energy, 2017) and we assume all households adopt and use smart or programmable thermostats at the high end. In low and middle income countries, we assume households adopt and use smart and programmable thermostats at a rate of 15 and 75%, representing the current rates for the United States and the state of New York, respectively (Lockheed Martin Energy, 2017; U.S. EIA, 2023a).

Table 6. Range of achievable adoption levels. 

Unit: smart or programmable thermostats put to use for saving energy on heating

Current adoption 140,000,000
Achievable – low 290,000,000
Achievable – high 510,000,000
Adoption ceiling 650,000,000

Unit: smart or programmable thermostats put to use for saving energy on cooling

Current adoption 30,000,000
Achievable – low 190,000,000
Achievable – high 510,000,000
Adoption ceiling 580,000,000

Impacts

For space heating, current adoption and use of a smart or programmable thermostat to save energy has an estimated climate impact of 0.033 Gt CO₂‑eq/yr globally (100- and 20-year basis; Table 7a). If all households with heating were to adopt and use these thermostats, the estimated climate impact would be 0.15 Gt CO₂‑eq/yr (100- and 20-year basis). We estimate the achievable range to be 0.065–0.12 Gt CO₂‑eq/yr (100- and 20-year basis). 

For space cooling, current adoption and use of a smart or programmable thermostat to save energy has an estimated climate impact of 0.0028 Gt CO₂‑eq/yr globally (100- and 20-year basis; Table 7b). If all households with cooling were to adopt and use these thermostats, the estimated climate impact would be 0.052 Gt CO₂‑eq/yr (100-year basis) and 0.053 Gt CO₂‑eq/yr (20-year basis). We estimate the achievable range to be 0.017–0.46 Gt CO₂‑eq/yr (100-year basis) and 0.018–0.47 Gt CO₂‑eq/yr (20-year basis). 

The impact from heating is greater than the impact from cooling because there are more households that use heating and more energy is needed on average per household for heating. 

Table 7. Climate impact at different levels of adoption.

Unit: Gt CO₂‑eq )/yr for heating, 100-yr basis

Current adoption 0.033
Achievable – low 0.065
Achievable – high 0.12
Adoption ceiling 0.15

Unit: Gt CO₂‑eq/yr for cooling, 100-yr basis

Current adoption 0.0028
Achievable – low 0.017
Achievable – high 0.046
Adoption ceiling 0.052

Income and Work

When used as intended, smart and programmable thermostats can save money by reducing energy use (Blonz et al., 2025; Lu et al., 2010; Wang et al., 2020). The cost savings can vary depending on the type of thermostat, fuel used for heating, geographic location, and sources of energy used to generate electricity. In our estimates, on average, households using smart or programmable thermostats could save US$84/yr on heating and US$21/yr on cooling (see Table 2). Where time-of-use electricity pricing exists, smart and programmable thermostats can be used to heat or cool a home in advance of peak periods to save even more (Chassin et al., 2015). 

Health

A reduction in energy demand from smart thermostats may lower air pollution and limit exposure to pollutants such as lead and fine particulate matter generated by fossil fuel-based power plants, thereby improving health in nearby communities (Henneman et al., 2023; U.S. Environmental Protection Agency [U.S. EPA], 2026). 

Air Quality

Reducing energy use can reduce climate and air pollutants associated with burning fossil fuels, such as CO₂, nitrogen oxides, methane, lead, and fine particulate matter (U.S. EPA, 2026).

Other

Smart or programmable thermostats may be more difficult to implement in multiunit residential buildings with centralized heating and cooling systems in which units do not have temperature control (Fine & Touchie, 2020). Additionally, some existing space heating systems such as fireplaces and wood stoves may not be compatible with programmable thermostats. 

The Government of Canada (2025) recommends minimizing temperature setbacks for heat pumps or programming the return to normal temperatures in stages to avoid triggering the use of less efficient backup heating systems. 

This solution depends on households programming their thermostat or directing a smart thermostat to save energy. As with any outcome that depends on behavior change, post-intervention persistence can decay over time (Allcott & Rogers, 2014). Comfort concerns, changes to schedules, low perceived benefits, and lack of perceived control over heating and cooling systems are common reasons why households inactivate thermostat programming (Heatherly et al., 2023; Peffer et al., 2013; Pritoni et al., 2015; Stopps & Touchie, 2021). 

Some studies show little to no change in energy use with programmable thermostats, particularly if the thermostats are not easy to use (Peffer et al., 2013). Energy savings setbacks are more likely to be used with smart thermostats than programmable ones (Stopps & Touchie, 2021; Tamas et al., 2021), likely because of improved ease of use and increased automation. 

Use of smart and programmable thermostats reduces the emissions from operating buildings. However, these reductions pale in comparison to those offered by heat pumps and decarbonizing the electricity sector by adopting solutions such as distributed solar PVutility-scale solar PVonshore wind, and offshore wind.

Smart and programmable thermostats have the potential to increase peak demand for electricity when programmed around common schedules. For example, thermostats may be programmed to raise temperatures in the early morning in winter when electricity grids are already strained (Lee & Max Zhang, 2022). Conversely, grid-integrated thermostats can reduce grid peaks by optimizing when heating or cooling occurs while maintaining occupant comfort (Kini et al., 2025).

When large numbers of households use smart or programmable thermostats to save energy, it can unintentionally cause spikes in electricity demand when heating systems are simultaneously turned on to return temperatures to normal (Lee & Max Zhang, 2022). These spikes can increase overall grid capacity needs and increase demand from fossil-fueled peaking generation. Grid-interactive smart thermostats can reduce these spikes through grid level energy management (Lee et al., 2020). 

Competing

There are diminishing returns as solutions that reduce heating and cooling loads are combined. When smart or programmable thermostats reduce the energy and emissions from heating and cooling, they also reduce the emissions savings these other solutions achieve. 

Consensus of effectiveness in reducing GHG emissions: High 

There is strong consensus that smart and programmable thermostats will reduce energy use and associated emissions when used to regularly adjust temperatures. 

Numerous studies have demonstrated that energy savings with smart or programmable thermostats can be significant but also vary significantly. For example, A review by Yuan et al. (2024) of occupancy-based control studies for heating, air conditioning and ventilation systems found energy savings of 7–44%. Pang et al. (2021) noted that factors such as climate conditions, building characteristics, occupant behaviors, and setback temperatures can affect energy savings outcomes. 

Pritoni et al. (2016) found that field study outcomes for smart thermostats can differ from the outcomes predicted by models, which are the most common approach to estimating energy savings and, by extension, emissions savings. Factors that can account for some of this discrepancy include comfort preferences, overrides, poor programming, and occupancy (Pritoni et al., 2015; Stopps & Touchie, 2021). 

A major barrier to realizing energy savings with smart or programmable thermostats is getting households to use the programming feature. Bielig et al. (2025) demonstrated that smart thermostat adoption and use are tied to perceived value, usefulness, and ease of use in European Union countries. Meanwhile, Pritoni et al. (2015) highlighted how many U.S. households have a poor understanding of how and when programmed set points save energy, and identified challenges with programming thermostats and comfort concerns as barriers to their use. Smart thermostats that learn occupant behaviors and preferences have shown to be easier to use than programmable thermostats (Tamas et al., 2021) and can achieve higher energy savings with higher thermal comfort (Nägele et al., 2017).

The results presented in this document summarize findings from five original studies, 10 reports, nine databases, two market research reports, and 11 product information web pages. This reflects current evidence from 11 countries, primarily high-income countries, and seven global regions. We recognize this limited geographic scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions.

Take Action

Looking to get involved? Below are some key actions for this solution that can get you started, arranged according to different roles you may play in your professional or personal life.

These actions are meant to be starting points for involvement and are not intended to be prescriptive or necessarily suggest they are the most important or impactful actions to take. We encourage you to explore and get creative!

Lawmakers and Policymakers

  • Offer one-stop educational resources for thermostats; offer demonstrations for installation and programming through online videos and in-person demos; clearly state benefits of smart and programmable thermostats, highlighting the cost savings, social benefits, and environmental impacts.
  • Set clear and measurable targets for building efficiency, emissions reduction, and deployment of smart and programmable thermostats.
  • Ensure public procurement standards require smart and programmable thermostats for new construction; require retrofits for existing public buildings.
  • Create regulatory standards and building codes that encourage, incentivize, and/or require the use of smart and programmable thermostats, especially in new construction.
  • Periodically update codes, policies, and public guidance to keep pace with adoption and technology advances.
  • Encourage utilities to incentivize smart and programmable thermostat uptake and use for demand management.
  • Consider offering subsidies that allow for flexible implementation or selective applicability within national systems; ensure subsidy programs are designed based on scientific evidence showing they will have a positive impact on adoption for the intended beneficiaries; target subsidies to low- and middle-income households and simultaneously offer incentives for broadband and digital connectivity; ensure financial incentives cover both new installations and retrofits.
  • Focus broader policies on energy efficiency through the use of intelligent control.
  • Create regulatory standards and building codes that encourage, incentivize, and/or require the use of smart and programmable thermostats, especially in new construction.

Practitioners

  • Offer one-stop educational resources for thermostats; offer demonstrations for installation and programming through online videos and in-person demos; clearly state benefits of smart and programmable thermostats highlighting the cost savings, social benefits, and environmental impacts.
  • Offer free or discounted thermostats in electrically heated homes and homes with cooling in exchange for control when the electricity grid is strained. 
  • Ensure customers know they can upgrade their thermostats; provide recommendations to customers on purchasing, installing, and using smart and programmable thermostats; inform customers of public or private incentives for purchases and/or installation; educate customers on the savings, social, and environmental benefits of installation. 
  • Develop or offer easy-to-use smart and programmable thermostat systems; provide scheduled maintenance services for customers; bundle services with heating and cooling system services when possible; ensure customers have the option to review products and services online.
  • Offer thermostats that are compatible with widely used electronic devices such as laptops and smart phones; incorporate Wi-Fi, bluetooth, and the Internet of Things into thermostats, allow for remote control and visibility via smartphone apps.
  • Provide 0% financing options for bundled services, including thermostats and/or related energy efficiency measures.
  • Ease the learning curve for customers by providing clear, concise instructions; ensure elderly customers are comfortable with using the thermostat before leaving after installation.
  • Use customer feedback and work with manufacturers to simplify interface designs and improve functionality. 
  • Advertise for smart and programmable thermostats depicting individual savings on heating and cooling; use social media to reach broader audiences.
  • Create algorithms that can save energy and money for consumers by responding to time of use, customer behavior, and current weather; ensure thermostats have the ability to be updated for future improvements to the software.
  • When installing a thermostat, ensure it is easily accessible and will not be obstructed.
  • Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for smart and programmable thermostats.

Business Leaders

  • Help socialize the importance of smart and programmable thermostats by incorporating them into corporate net zero strategies; highlight the use of smart and programmable thermostats in public communications.
  • Invest in or offer grants to start-ups seeking to deploy smart and programmable thermostats; invest in research and development to determine optimal user interfaces and/or algorithms for smart and programmable thermostats.
  • Offer pro bono business advice to nonprofit organizations working to improve building efficiency and deploy smart and programmable thermostats.
  • Offer employees information or benefits for upgrading their thermostats at home.
  • Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for smart and programmable thermostats.

Nonprofit Leaders

  • Offer one-stop educational resources for thermostats; offer demonstrations for installation and programming through online videos and in-person demos; clearly state benefits of smart and programmable thermostats highlighting the cost savings, social benefits, and environmental impacts.
  • Help policymakers set clear and measurable targets for building efficiency, emissions reduction, and the deployment of smart and programmable thermostats.
  • Advocate for and help design regulatory standards and building codes that encourage, incentivize, and/or require the use of smart and programmable thermostats, especially in new construction.
  • Assist regulators in periodically updating codes, policies, and public guidance to keep pace with adoption and technology advances.
  • Advocate for subsidies that allow for flexible implementation or selective applicability within national systems; help ensure subsidy programs are designed based on scientific-evidence showing they will have a positive impact on adoption for the intended beneficiaries; recommend that subsidies be targeted to low- and middle-income households and simultaneously offer incentives for broadband and digital connectivity; help ensure financial incentives cover both new installations and retrofits.
  • Help shift policy frameworks to focus on energy efficiency through the use of intelligent control.
  • Conduct research to improve adoption and use of smart and programmable thermostats, paying close attention to how user interfaces impact behavior.
  • Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for smart and programmable thermostats.

Investors

  • Finance only new construction and retrofits that use smart or programmable thermostats as well as other energy-efficient heating and cooling technologies and practices.
  • Invest in research and development to improve smart and programmable thermostat design and user interface.
  • Invest in or offer grants to start-ups seeking to deploy smart and programmable thermostats.
  • Issue or buy green bonds to deploy capital to projects that use smart or programmable thermostats and integrate other energy-efficient heating and cooling technologies and practices.
  • Offer preferential loan agreements for developers using smart or programmable thermostats, energy efficient building practices, and other related climate solutions.
  • Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for smart and programmable thermostats.

Philanthropists and International Aid Agencies

  • Offer one-stop educational resources for thermostats; offer demonstrations for installation and programming through online videos and in-person demos; clearly state benefits of smart and programmable thermostats, highlighting the cost savings, social benefits, and environmental impacts.
  • Offer grants or access to no-interest financing for retrofits and installations of smart and programmable thermostats; ensure financial support for projects involving building retrofits or new construction; require the use of smart or programmable thermostats.
  • Offer grants or financing for research and development to improve smart and programmable thermostat design and user interface.
  • Invest in or offer grants to start-ups seeking to deploy smart or programmable thermostats.
  • Issue or buy green bonds to deploy capital to projects that use smart or programmable thermostats and integrate other energy-efficient heating and cooling technologies and practices.
  • Offer preferential loan agreements for developers using smart or programmable thermostats, energy efficient building practices, and other related climate solutions.
  • Help policymakers set clear and measurable targets for building efficiency, emissions reduction, and deployment of smart and programmable thermostats.
  • Advocate for and help design regulatory standards and building codes that encourage, incentivize, and/or require the use of smart and programmable thermostats, especially in new construction.
  • Help regulators periodically update codes, policies, and public guidance to keep pace with adoption and technology advances.
  • Advocate for subsidies that allow for flexible implementation or selective applicability within national systems; help ensure subsidy programs are designed based on scientific evidence showing they will have a positive impact on adoption for the intended beneficiaries; recommend that subsidies be targeted to low- and middle-income households and simultaneously offer incentives for broadband and digital connectivity; help ensure financial incentives cover both new installations and retrofits.
  • Help shift policy frameworks to focus on energy efficiency through the use of intelligent control.
  • Conduct research to improve adoption and use of smart and programmable thermostats, paying close attention to how user interfaces impact behavior.
  • Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for smart and programmable thermostats.

Thought Leaders

  • Help create educational efforts and resources for smart and programmable thermostats; offer demonstrations for installation and programming through online videos and in-person demos; clearly state benefits of smart and programmable thermostats, highlighting the cost savings, social benefits, and environmental impacts.
  • Help policymakers set clear and measurable targets for building efficiency, emissions reduction, and deployment of smart and programmable thermostats.
  • Advocate for and help design regulatory standards and building codes that encourage, incentivize, and/or require the use of smart or programmable thermostats, especially in new construction.
  • Help regulators periodically update codes, policies, and public guidance to keep pace with adoption and technology advances.
  • Advocate for subsidies that allow for flexible implementation or selective applicability within national systems; help ensure subsidy programs are designed based on scientific evidence showing they will have a positive impact on adoption for the intended beneficiaries; recommend that subsidies be targeted to low- and middle-income households and simultaneously offer incentives for broadband and digital connectivity; help ensure financial incentives cover both new installations and retrofits.
  • Help shift policy frameworks to focus on energy efficiency through the use of intelligent control.
  • Conduct research to improve adoption and use of smart and programmable thermostats, paying close attention to how user interfaces impact behavior.
  • Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for smart and programmable thermostats.

Technologists and Researchers

  • Develop smart systems that integrate thermostats into a systems level perspective, allowing thermostats to make adjustments based on household energy consumption; design these systems for automatic adjustments to energy usage depending on price signals, energy spikes, appliance use, charging time (e.g., for EVs), weather patterns, occupancy, and related factors; ensure thermostats can automatically update utility rates, weather forecasts, and other data that support cost- and energy-efficient use.
  • Develop smart thermostats and smart home systems that can be grid-integrated for demand management. 
  • Design software for smart and programmable thermostats that provides detailed feedback and individualized suggestions to consumers on energy usage, costs, and estimated savings.
  • Research how users interact with smart and programmable thermostats; examine impact of user interfaces (UIs) on consumer use; develop simplified UIs to facilitate adoption.
  • Research the relationship between household decision-making and smart or programmable thermostat adoption; highlight recommendations for reaching household decision-makers.

Communities, Households, and Individuals

  • Upgrade to a smart or programmable thermostat, learn how to use its features, set the programming accordingly, and override the system as little as possible.
  • Consult and work with licensed heating and cooling system installers to determine best available options for smart or programmable thermostats, installation, and maintenance.
  • Make sure your thermostat is installed in a position that allows for easy, unobstructed access.
  • Take advantage of public incentives such as subsidies or low-interest financing for installation, retrofits, and/or maintenance.
  • If provided by your smart thermostat or energy provider, opt into alerts that inform you of abnormally high energy usage which can be an early warning of problems with a heating and cooling system.
  • Take time to understand your smart or programmable thermostat; use profile settings and scheduling to optimize energy and money savings.
  • If you own a smart thermostat, opt into demand response programs to lower energy consumption during peak times; turn on notifications for heating and cooling system maintenance.
  • Share your experience with your neighbors, community, and social networks, and offer help in programming a thermostat where appropriate.
  • If possible, regularly schedule heating and cooling system maintenance and upgrades, including for related equipment such as thermostats. 
  • If smart or programmable thermostats are not an option, manually adjust your thermostat to reduce energy consumption when you’re not home, during peak hours, or to reflect weather conditions; consult your energy provider for tips on thermostat adjustments that can save money and energy.

“Take Action” Sources

References

Alhamayani, A. D., Sun, Q., & Hallinan, K. P. (2021). Estimating smart Wi-Fi thermostat-enabled thermal comfort control savings for any residence. Clean Technologies3(4), 743–760. Link to source: https://doi.org/10.3390/cleantechnol3040044  

Allcott, H., & Rogers, T. (2014). The short-run and long-run effects of behavioral interventions: Experimental evidence from energy conservation. American Economic Review104(10), 3003–3037. Link to source: https://doi.org/10.1257/aer.104.10.3003  

Bergeron, R. (2024, May 9). Installation obligatoire d’un thermostat connecté en 2027. Expertise Rénovation. Link to source: https://www.expertise-renovation.com/actualites/installation-thermostat-connecte  

Bielig, M., Kutzner, F., Klingert, S., & Kacperski, C. (2025). Understanding intention to adopt smart thermostats: The role of individual predictors and social beliefs across five EU countries: Proceedings of the 14th International Conference on Smart Cities and Green ICT Systems1, 36–47. Link to source: https://doi.org/10.5220/0013356200003953  

Blonz, J., Palmer, K., Wichman, C. J., & Wietelman, D. C. (2025). Smart thermostats, automation, and time-varying prices. American Economic Journal: Applied Economics17(1), 90–125. Link to source: https://doi.org/10.1257/app.20210618  

Chassin, D. P., Stoustrup, J., Agathoklis, P., & Djilali, N. (2015). A new thermostat for real-time price demand response: Cost, comfort and energy impacts of discrete-time control without deadband. Applied Energy155, 816–825. Link to source: https://doi.org/10.1016/j.apenergy.2015.06.048 

EGIA Contractor University. (2025). Average service life of residential HVAC equipment. Link to source: https://library.mycontractoruniversity.com/wp-content/uploads/2025/10/EGIA-AverageServiceLife.pdf  

Ellsworth, R. (2026, February 12). Residential HVAC industry statistics. ZipDo Education Reports. Link to source: https://zipdo.co/residential-hvac-industry-statistics/  

Energy Star. (2017). Energy Star® program requirements for connected thermostat products: Partner commitments. Link to source: https://www.energystar.gov/sites/default/files/asset/document/ENERGY%20STAR%20Program%20Requirements%20for%20Connected%20Thermostats%20Version%201.0_0.pdf  

Energy Transitions Commission. (2025). Achieving zero-carbon buildings: Electric, efficient and flexible [Report]. Link to source: https://static.energy-transitions.org/uploads/resources/ETC_Buildings-Decarbonisation-Report_DIGITALFINAL.pdf  

Falchetta, G., Cian, E. D., Pavanello, F., & Wing, I. S. (2024). Inequalities in global residential cooling energy use to 2050. Nature Communications15(1), Article 7874. Link to source: https://doi.org/10.1038/s41467-024-52028-8  

Fine, J. P., & Touchie, M. F. (2020). A grouped control strategy for the retrofit of post-war multi-unit residential building hydronic space heating systems. Energy and Buildings208, Article 109604. Link to source: https://doi.org/10.1016/j.enbuild.2019.109604  

Ge, M., Friedrich, J., & Vigna, L. (2026, April 27). Where do emissions come from? These charts explain greenhouse gas emissions by sector. World Resources Institute. Link to source: https://www.wri.org/insights/4-charts-explain-greenhouse-gas-emissions-countries-and-sectors   

Government of Canada. (2025). Heating and cooling with a heat pump. Link to source: https://natural-resources.canada.ca/energy-efficiency/energy-star/heating-cooling-heat-pump#hds  

Hendron, R., German, A., & Pereira, J. (2021). Modeling savings for Energy Star smart home energy management systems. National Renewable Energy Laboratory. Link to source: https://docs.nlr.gov/docs/fy21osti/79534.pdf 

Henneman, L., Choirat, C., Dedoussi, I., Dominici, F., Roberts, J., & Zigler, C. (2023). Mortality risk from United States coal electricity generation. Science382(6673), 941–946. Link to source: https://doi.org/10.1126/science.adf4915  

International Energy Agency. (2023). Space heating. Link to source: https://www.iea.org/reports/space-heating#dashboard  

Kini, R. L., Vlachokostas, A., Brambley, M. R., & Rogers, A. (2025). Occupant-centric demand response for thermostatically-controlled home loads. IEEE Transactions on Smart Grid16(3), 2234–2245. Link to source: http://doi.org/10.1109/TSG.2025.3540427  

Lee, Z. E., & Max Zhang, K. (2022). Unintended consequences of smart thermostats in the transition to electrified heating. Applied Energy322, Article 119384. Link to source: https://doi.org/10.1016/j.apenergy.2022.119384  

Lee, Z. E., Sun, Q., Ma, Z., Wang, J., MacDonald, J. S., & Max Zhang, K. (2020). Providing grid services with heat pumps: A review. ASME Journal of Engineering for Sustainable Buildings and Cities1(1), Article 011007. Link to source: https://doi.org/10.1115/1.4045819  

Lu, J., Sookoor, T., Srinivasan, V., Gao, G., Holben, B., Stankovic, J., Field, E., & Whitehouse, K. (2010). The smart thermostat: Using occupancy sensors to save energy in homes. Proceedings of the 8th ACM Conference on Embedded Networked Sensor Systems, SenSys ’10, 211–224. Link to source: https://doi.org/10.1145/1869983.1870005

Mourshed, M. (2016). Climatic parameters for building energy applications: A temporal-geospatial assessment of temperature indicators. Renewable Energy94, 55–71. Link to source: https://doi.org/10.1016/j.renene.2016.03.021  

Nägele, F., Kasper, T., & Girod, B. (2017). Turning up the heat on obsolete thermostats: A simulation-based comparison of intelligent control approaches for residential heating systems. Renewable and Sustainable Energy Reviews75, 1254–1268. Link to source: https://doi.org/10.1016/j.rser.2016.11.112  

Lockheed Martin Energy. (2017). Home energy management system savings validation pilot [NYSERDA Report 17-16]. New York State Energy Research and Development Authority. Link to source: https://www.ashb.com/wp-content/uploads/2020/04/IS-2019-05.pdf  

Pang, Z., Chen, Y., Zhang, J., O’Neill, Z., Cheng, H., & Dong, B. (2021). How much HVAC energy could be saved from the occupant-centric smart home thermostat: A nationwide simulation study. Applied Energy283, Article 116251. Link to source: https://doi.org/10.1016/j.apenergy.2020.116251  

Peffer, T., Perry, D., Pritoni, M., Aragon, C., & Meier, A. (2013). Facilitating energy savings with programmable thermostats: Evaluation and guidelines for the thermostat user interface. Ergonomics56(3), 463–479. Link to source: https://doi.org/10.1080/00140139.2012.718370  

Pew Research Center. (2019). Religion and living arrangements around the world. Link to source: https://www.pewresearch.org/wp-content/uploads/sites/20/2019/12/PF_12.12.19_religious.households.FULL_.pdf  

Pritoni, M., Meier, A. K., Aragon, C., Perry, D., & Peffer, T. (2015). Energy efficiency and the misuse of programmable thermostats: The effectiveness of crowdsourcing for understanding household behavior. Energy Research & Social Science8, 190–197. Link to source: https://doi.org/10.1016/j.erss.2015.06.002  

Pritoni, M., Woolley, J. M., & Modera, M. P. (2016). Do occupancy-responsive learning thermostats save energy? A field study in university residence halls. Energy and Buildings127, 469–478. Link to source: https://doi.org/10.1016/j.enbuild.2016.05.024  

Statistics Canada. (2025). Use of thermostats [Data set]. Link to source: https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=3810004901  

Stopps, H., & Touchie, M. F. (2021). Residential smart thermostat use: An exploration of thermostat programming, environmental attitudes, and the influence of smart controls on energy savings. Energy and Buildings238, Article 110834. Link to source: https://doi.org/10.1016/j.enbuild.2021.110834  

Stopps, H., & Touchie, M. F. (2022). Load shifting and energy conservation using smart thermostats in contemporary high-rise residential buildings: Estimation of runtime changes using field data. Energy and Buildings255, Article 111644. Link to source: https://doi.org/10.1016/j.enbuild.2021.111644  

Tamas, R., O’Brien, W., & Quintero, M. S. (2021). Residential thermostat usability: Comparing manual, programmable, and smart devices. Building and Environment203, Article 108104. Link to source: https://doi.org/10.1016/j.buildenv.2021.108104  

World Bank. (n.d.). Mapping energy efficiency: A global dataset on building code effectiveness and compliance [Methodology note]. Link to source: https://www.worldbank.org/content/dam/sites/buildinggreen/doc/building_green_methodology.pdf  

United Nations. (2024). World population prospects 2024 - Special aggregates [Data set]. Link to source: https://population.un.org/wpp/downloads?folder=Special%20Aggregates&group=UN-related%20groups   

U.S. Energy Information Administration. (2018a). Table HC6.1 Space heating in U.S. homes, by housing unit type, 2015 [Data set]. Link to source: https://www.eia.gov/consumption/residential/data/2015/  

U.S. Energy Information Administration. (2018b). Table HC7.1 Air conditioning in U.S. homes by housing unit type, 2015 [Data set]. Link to source: https://www.eia.gov/consumption/residential/data/2015/  

U.S. Energy Information Administration. (2023a). Table HC6.1 Space heating in U.S. homes, by housing unit type, 2020 [Data set]. Link to source: https://www.eia.gov/consumption/residential/data/2020/hc/pdf/HC%206.1.pdf  

U.S. Energy Information Administration. (2023b). Table HC7.1 Air conditioning in U.S. homes, by housing unit type, 2020 [Data set]. Link to source: https://www.eia.gov/consumption/residential/data/2020/hc/pdf/HC%207.1.pdf  

U.S. Environmental Protection Agency. (2026). Power sector programs—Progress report. Link to source: https://www.epa.gov/power-sector/progress-report  

Wang, C., Pattawi, K., & Lee, H. (2020). Energy saving impact of occupancy-driven thermostat for residential buildings. Energy and Buildings211, Article 109791. Link to source: https://doi.org/10.1016/j.enbuild.2020.109791  

Yuan, Y., Song, C., Gao, L., Zeng, K., & Chen, Y. (2024). A review of current research on occupant-centric control for improving comfort and energy efficiency. Building Simulation17(10), 1675–1692. Link to source: https://doi.org/10.1007/s12273-024-1170-1  

Credits

Lead Fellow

  • Heather McDiarmid, Ph.D

Contributors

  • Ruthie Burrows, Ph.D.

  • James Gerber, Ph.D.

  • Daniel Jasper

  • Alex Sweeney

Internal Reviewers

  • Henry Igugu, Ph.D.

  • Amanda D. Smith, Ph.D.

  • Christina Swanson, Ph.D.

Methods and Supporting Data

  • Greenhouse gas quantity expressed relative to CO₂ with the same warming impact over 100 years, calculated by multiplying emissions by the 100-yr GWP for the emitted gases.

  • Greenhouse gas quantity expressed relative to CO with the same warming impact over 20 years, calculated by multiplying emissions by the 20-yr GWP for the emitted gases.

  • 8th World Congress on Conservation Agriculture

  • Reducing greenhouse gas concentrations in the atmosphere by preventing or reducing emissions.

  • A liquid with a low pH (below 7).

  • The process of increasing acidity.

  • The extent to which emissions reduction or carbon removal is above and beyond what would have occurred without implementing a particular action or solution.

  • An upper limit on solution adoption based on physical or technical constraints, not including economic or policy barriers. This level is unlikely to be reached and will not be exceeded.

  • The quantity and metric to measure implementation for a particular solution that is used as the reference unit for calculations within that solution.

  • A composting method in which organic waste is processed in freestanding piles that can be aerated actively with forced air or passively by internal convection.

  • The interactions of aerodynamic forces and flexible structures, often including the stucture's control system.

  • A process in which microbes break down organic materials in the presence of oxygen. This process converts food and green waste into nutrient-rich compost.

  • Establishment of new forests in areas that did not historically support forests.

  • Farming practices that work to create socially and ecologically sustainable food production.

  • Addition of trees and shrubs to crop or animal farming systems.

  • Artificial intelligence

  • Spread out the cost of an asset over its useful lifetime.

  • A process in which microorganisms break down organic material in the absence of oxygen. Methane and CO₂ are the main byproducts.

  • A crop that live one year or less from planting to harvest; also called annual.

  • Lacking dissolved oxygen but containing other sources of oxygen bound within molecules that can be stripped and used by microorganisms.

  • aerated static piles

  • Hardware required to support PV modules and arrays, including racking and mounting structures, wires, and other physical components.

  • Building automation system

  • Electric power delivered at a steady, around-the-clock rate, to cover power demand that exists at all times. Baseload power is typically supplied by high availability, low operating-cost plants, such as nuclear or geothermal.

  • A liquid with a high pH (above 7).

  • black carbon

  • Solar panels that generate electricity from sunlight captured on both sides, increasing energy output by reflecting light from the ground and surroundings.

  • Made from material of biological origin, such as plants, animals, or other organisms.

  • A renewable energy source generated from organic matter from plants and/or algae.

  • An energy source composed primarily of methane and CO that is produced by microorganisms when organic matter decomposes in the absence of oxygen.

  • Carbon stored in biological matter, including soil, plants, fungi, and plant products (e.g., wood, paper, biofuels). This carbon is sequestered from the atmosphere but can be released through decomposition or burning.

  • Living or dead renewable matter from plants or animals, not including organic material transformed into fossil fuels. Peat, in early decay stages, is partially renewable biomass.

  • Biogas refined to the same quality as natural gas. CO₂ and impurities are removed, and the biomethane can be distributed and used in existing natural gas technologies.
     

  • A type of carbon sequestration that captures carbon from CO via photosynthesis and stores it in soils, sediments, and biomass, distinct from sequestration through chemical or industrial pathways.

  • A synthetic organic compound used to make a type of hard, clear plastic for food and drink packaging and many consumer goods.

  • A climate pollutant, also called soot, produced from incomplete combustion of organic matter, either naturally (wildfires) or from human activities (biomass or fossil fuel burning).

  • A secure, decentralized way of digitally tracking transactions that could be used to improve the transparency and efficiency of carbon markets. 

  • Fixed income debt instruments focused on sustainable ocean projects. Blue bonds work in the same manner as traditional bonds and may be issued by corporations, financial institutions, and governments.

  • A global initiative launched by Germany and the IUCN in 2011 to restore 150 Mha of land by 2020 and 350 Mha by 2030.

  • High-latitude (>50°N or >50°S) climate regions characterized by short growing seasons and cold temperatures.

  • Balance-of-system

  • bisphenol A

  • Revenue from carbon credits reserved for payout to land- and rights-holders in the event of a disturbance such as a fire; similar to insurance scheme.

  • The components of a building that physically separate the indoors from the outdoor environment.

  • Businesses involved in the sale and/or distribution of solution-related equipment and technology, and businesses that want to support adoption of the solution.

  • Compound annual growth rate

  • A chemical reaction involving heating a solid to a high temperature; to make cement clinker, limestone is calcined into lime in a process that requires high heat and produces CO.

  • The ratio of the actual electricity an energy technology generates over a period of time to the maximum it could have produced if it operated continuously at full capacity.

  • A four-wheeled passenger vehicle.

  • Average number of people traveling in a car per trip.

  • Technologies that collect CO before it enters the atmosphere, preventing emissions at their source. Collected CO can be used onsite or in new products, or stored long term to prevent release.

  • A greenhouse gas that is naturally found in the atmosphere. Its atmospheric concentration has been increasing due to human activities, leading to warming and climate impacts.

  • Total GHG emissions resulting from a particular action, material, technology, or sector.

  • Amount of GHG emissions released per activity or unit of production. 

  • A marketplace where carbon credits are purchased and sold. One carbon credit represents activities that avoid, reduce, or remove one metric ton of GHG emissions.

  • A colorless, odorless gas released during the incomplete combustion of fuels containing carbon. Carbon monoxide can harm health and be fatal at high concentrations.

  • The time it takes for the emissions reduction from a measure to equal the emissions invested in implementing the measure.

  • Activities or technologies that pull CO out of the atmosphere, including enhancing natural carbon sinks and deploying engineered sinks.

  • Long-term storage of carbon in soils, sediment, biomass, oceans, and geologic formations after removal of CO from the atmosphere or CO capture from industrial and power generation processes.

  • The interconnected pool of dissolved inorganic carbon forms in water. Composed of dissolved CO₂, carbonic acid, bicarbonate ions, and carbonate ions.

  • The stocking rate a pasture can sustain without degrading forage supply or vegetation condition.

  • carbon capture and storage

  • carbon capture, utilization, and storage

  • Cooling degree days

  • A binding ingredient in concrete responsible for most of concrete’s life-cycle emissions. Cement is made primarily of clinker mixed with other mineral components.

  • chlorofluorocarbon

  • Processes that use chemical reactions or heat to break down plastic waste into basic molecular components or feedstocks that can then be used to make new plastic products.

  • Process that uses chemical reactions or heat to break down plastic waste into basic molecular components that can be used to make new plastic products.

  • methane

  • A system in which resources, materials, and products are used for as long as possible through reuse, repair, refurbishment, and recycling.

  • Energy sources that have little to no negative environmental or climate impacts during operation relative to fossil fuel–based energy sources.

  • A factor that warms or cools the planet.

  • Gases or particles that have a planet-warming effect when released to the atmosphere. Some climate pollutants also cause other forms of environmental damage.

  • Areas that have natural buffers from local climate change impacts, offering safe havens for species and ecosystems.

  • A binding ingredient in cement responsible for most of the life-cycle emissions from cement and concrete production.

  • A waste management process where waste is made into the same original product, preserving quality and value so materials can be reused multiple times while keeping resources in continuous use.

  • A system that encompasses both forward supply chains (from producer to consumer) and reverse logistics for reuse, recycling, or proper disposal.

  • Neighbors, volunteer organizations, hobbyists and interest groups, online communities, early adopters, individuals sharing a home, and private citizens seeking to support the solution.

  • A solution that potentially lowers the benefit of another solution through reduced effectiveness, higher costs, reduced or delayed adoption, or diminished global climate impact.

  • The average annual rate at which a value grows over a specified period, assuming profits are reinvested and growth occurs steadily each year.

  • Funding with substantially more generous terms than market loans (typically due to lower interest rates, longer repayment periods, or partial grants) used to support projects with public or development benefits.

  • A farming system that combines reduced tillage, cover crops, and crop rotations.

  • The proportion of water used or applied that is evaporated, transpired, or incorporated into a product and therefore is not returned to the local hydrological system through runoff or leaching.

  • Risk-sharing financial agreements in which two parties (e.g., renewable generator, government) guarantee a fixed price (e.g., electricity price). If market prices fluctuate, one party pays the other the difference.

  • Persistent long, thin clouds that form behind aircraft when water vapor in the exhaust condenses, then freezes into ice crystals at high altitudes. 

  • A measure of the total space cooling demand to maintain an indoor temperature below 24 °C

  • carbon dioxide

  • A  measure standardizing the warming effects of greenhouse gases relative to CO. CO-eq is calculated as quantity (metric tons) of a particular gas multiplied by its GWP.

  • carbon dioxide equivalent

  • Plant materials left over after a harvest, such as stalks, leaves, and seed husks.

  • A granular material made by crushing broken or waste glass.

  • direct air capture

  • Financial agreements in which government creditors forgive a portion of debt in exchange for specific conservation commitments.

  • The process of cutting greenhouse gas emissions (primarily CO) from a particular sector or activity.

  • An industrial process that removes printing ink from used or waste paper fibers, creating clean pulp that can be turned into new paper products.

  • A solution that works slower than gradual solutions and is expected to take longer to reach its full potential.

  • Microbial conversion of nitrate into inert nitrogen gas under low-oxygen conditions, which produces the greenhouse gas nitrous oxide as an intermediate compound.

  • Electronic document that verifies whether a product has been manufactured according to environmental and social standards and/or material origins, environmental impact, and disposal recommendations.

  • Electronic documents that verify whether or not a product has been manufactured according to environmental and social standards and/or material origins, environmental impact, and disposal recommendations.

  • Greenhouse gas emissions produced as a direct result of the use of a technology or practice.

  • Electric power that can be increased, decreased, or turned on/off to match real-time fluctuations in grid conditions. Typically supplied by fast-responding plants such as natural gas, hydroelectric, or battery storage.

  • The inorganic forms of carbon dissolved in seawater. Composed of dissolved CO₂, carbonic acid, bicarbonate ions, and carbonate ions.

  • A system of underground distribution pipes that supply heat from centralized sources to a large number of buildings for space and water heating or industrial use.

  • A window consisting of two glass panes separated by a sealed gap and typically filled with air or an inert gas to improve the heat flow resistance.

  • A waste management system that transforms waste into different products of lower quality and value, making materials harder to recycle again and limiting reuse.

  • A measure of how long removed carbon stays out of the atmosphere.

  • Flexible benchmarks derived from independent, publicly available, frequently updated data sets.

  • European Energy Agency

  • Ability of a solution to reduce emissions or remove carbon, expressed in CO-eq per installed adoption unit. Effectiveness is quantified per year when the adoption unit is cumulative over time.

  • Enhanced geothermal system

  • Exajoule (one quintillion joules)

  • A process that uses electric current to drive a reaction, such as using electricity to split water molecules into hydrogen and oxygen.

  • Produced by electrolysis.

  • Greenhouse gas emissions accrued over the lifetime of a material or product, including as it is produced, transported, used, and disposed of.

  • Solutions that work faster than gradual solutions, front-loading their impact in the near term.

  • Methane produced by microbes in the digestive tracts of ruminant livestock, such as cattle, sheep and goats.

  • The unintended capture of organisms in intake flows.

  • Environmental Protection Agency

  • Extended Producer Responsibility

  • expanded polystyrene

  • Environmental Research & Education Foundation

  • environmental, social, and governance

  • exchange-traded fund

  • A process triggered by an overabundance of nutrients in water, particularly nitrogen and phosphorus, that stimulates excessive plant and algae growth and can harm aquatic organisms.

  • Electric vehicle

  • The movement of water from the earth’s surface to the atmosphere directly from land or water surfaces (evaporation) and through plant tissues (transpiration).

     

  • The scientific literature that supports our assessment of a solution's effectiveness.

  • A policy framework that assigns responsibility to producers for the end-of-life servicing of their products.

  • A group of human-made molecules that contain fluorine atoms. They are potent greenhouse gases with GWPs that can be hundreds to thousands times higher than CO.

  • Food, agriculture, land, and ocean

  • Food and Agriculture Organization of the United Nations

  • feed conversion ratio

  • The efficiency with which an animal converts feed into increased body mass, measured as the ratio of the weight of the feed given to weight gain. Lower FCR means less feed for the same growth.

  • A policy mechanism that incentivizes renewables through contracts that guarantee a set price for the electricity generated.

  • Raw material inputs for manufacturing, processing, and managing waste.

  • Containing or consisting of iron.

  • A measure of fishing activity over time and area, commonly measured by number of trips, vessel time, or gear deployed.

  • A solar PV system with panels mounted at a constant angle.

  • Glass is manufactured by floating molten glass on a molten tin bath, producing a smooth, flat product with high optical clarity, often used for window applications.

  • food loss and waste

  • Food discarded during pre-consumer supply chain stages, including production, harvest, and processing.

  • Food discarded during pre-consumer supply chain stages, including production, harvest, and processing, along with food discarded wt the retail and consumer stages of the supply chain.

  • Food discarded at the retail and consumer stages of the supply chain.

  • Combustible materials found in Earth's crust that can be burned for energy, including oil, natural gas, and coal. They are formed from decayed organisms through prehistoric geological processes.

  • Free, prior, and informed consent

  • A principled process of working with Indigenous communities that requires consent from Indigenous peoples for any decision, action, or activity that impacts their community and/or lands.

  • Unintentional leaks of gases or vapor into the atmosphere.

  • A group of countries representing the majority of the world's population, trade, and GDP. There are 19 member countries plus the European Union and the African Union

  • Gas collection and control system

  • A design or approach to policy, programs, or activities that addresses the different situations, roles, needs, and interests of women, men, girls, and boys.

  • Manipulating the environment to influence the quantities or impact of climate pollutants in the atmosphere.

  • Heavy-duty, low-permeability liners made mostly from synthetic plastics or rubber, used to block the movement of liquids or gases in engineered storage sites.

  • greenhouse gas

  • Global horizontal irradiance

  • gigajoule or billion joules

  • The glass layers or panes in a window.

  • The intensity of all solar radiant energy on a horizontal surface over a specific time frame, which limits PV power output. Measured as energy per area per year (kWh/m2/yr).

  • A measure of how effectively a gas traps heat in the atmosphere relative to CO. GWP converts greenhouse gases into CO-eq emissions based on their 20- or 100-year impacts.

  • A solution that has a steady impact on the atmosphere. Effectiveness is expected to be constant over time rather than having a higher impact in the near or long term.

  • A system that uses the slope of a field and furrows, borders, or flooding to apply water without pumping.

  • Hydrogen produced from natural gas, most commonly by combining heated steam with methane. Producing grey hydrogen emits CO₂ and leaks methane. Most hydrogen made today is grey.

  • A fixed income debt instrument focused on sustainable projects. Green bonds work in the same manner as traditional bonds and may be issued by corporations, financial institutions, and governments.

  • A fixed income debt instrument focused on sustainable projects. They work in the same manner as traditional bonds and may be issued by corporations, financial institutions, and governments.

  • Hydrogen gas made through electrolysis using electricity produced onsite using renewable energy sources.

  • The practice of charging more for renewable energy than for conventional energy to cover added costs .

  • Roofs that are designed to be partially or completely covered in vegetation.

  • Biomass discarded during landscaping and gardening.

  • A gas that traps heat in the atmosphere, contributing to climate change.

  • The makeup of electricity generation on a power grid, showing the share contributed by various energy sources (e.g., coal, natural gas, nuclear, wind, solar, hydro) relative to total electricity production.

  • A process by which GHGs dissolved in groundwater are released to the atmosphere when the groundwater is extracted from the aquifer.

  • metric gigatons or billion metric tons

  • global warming potential

  • A low-carbon steel-making technology that uses hydrogen from water, direct reduction of iron, and electric arc furnaces. 

  • hectare

  • household air pollution

  • A sector or process that is exceptionally challenging to decarbonize, often because of a lack of mature technology options.  

  • hydrochlorofluorocarbon

  • Number of years a person is expected to live without disability or other limitations that restrict basic functioning and activity.

  • A measure of the total space heating demand to maintain an indoor temperature above 18 °C

  • A unit of land area comprising 10,000 square meters, roughly equal to 2.5 acres.

  • Hybrid electric car

  • hydrofluorocarbon

  • hydrofluoroolefin

  • hydrofluoroolefin

  • high-income countries

  • Metal waste that is produced at a mill or foundry during the metal production process and recycled internally.

  • Particles and gases released from use of polluting fuels and technologies such as biomass cookstoves that cause poor air quality in and around the home.

  • heating, ventilation, air conditioning, and refrigeration

  • Organic compounds that contain hydrogen and carbon.

  • Human-made F-gases that contain hydrogen, fluorine, and carbon. They typically have short atmospheric lifetimes and GWPs hundreds or thousands times higher than CO

  • Human-made F-gases that contain hydrogen, fluorine, and carbon, with at least one double bond. They have low GWPs and can be climate-friendly alternatives to HFC refrigerants.

  • A recycling process that separates fibers from contaminants for reuse. Paper or cardboard is mixed with water to break down fibrous materials into pulp.

  • internal combustion engine

  • International Energy Agency

  • Aerobic decomposition of organic waste in a sealed container or bin/bay system. 

  • Greenhouse gas emissions produced as a result of a technology or practice but not directly from its use.

  • A solid block of purified silicon formed by melting and crystallizing raw silicon; it serves as the base material for slicing into wafers used in solar cells.

  • Device used to power vehicles by the intake, compression, combustion, and exhaust of fuel that drives moving parts.

  • The annual discount rate that balances net cash flows for a project over time. Also called IRR, internal rate of return is used to estimate profitability of potential investments.

  • Individuals or institutions willing to lend money in search of a return on their investment.

  • Intergovernmental Panel on Climate Change

  • Indigenous peoples’ land

  • Integrated pest management.

  • internal rate of return

  • The timing and amount of irrigation water applied.

  • International Union for Conservation of Nature

  • The most comprehensive global list of species threatened with extinction, maintained by the International Union for Conservation of Nature.

  • International agreement adopted in 2016 to phase down the use of high-GWP HFC F-gases over the time frame 2019–2047.

  • A measure of energy equivalent to the energy delivered by 1,000 watts of power over one hour.

  • kiloton or one thousand metric tons

  • kilowatt-hour

  • The intentional or unintentional act of property use crossing ownership boundaries without permission.

  • A land-holding system, e.g. ownership, leasing, or renting. Secure land tenure means farmers or other land users will maintain access to and use of the land in future years.

  • Gases, mainly methane and CO, created by the decomposition of organic matter in the absence of oxygen.

  • levelized cost of electricity

  • leak detection and repair

  • Regular monitoring for fugitive methane leaks throughout oil and gas, coal, and landfill sector infrastructure and the modification or replacement of leaking equipment.

  • Relocation of emissions-causing activities outside of a mitigation project area rather than a true reduction in emissions.

  • The rate at which solution costs decrease as adoption increases, based on production efficiencies, technological improvements, or other factors.

  • Percent decrease in costs per doubling of adoption.

  • A metric describing the expected break-even cost of generating electricity per megawatt-hour ($/MWh), combining costs related to capital, operation, and fuel (if used) and dividing by total output over the generator's lifetime.

  • landfill gas

  • Greenhouse gas emissions from the sourcing, production, use, and disposal of a technology or practice.

  • A process that converts biomass, plastics, or other solid wastes into liquid fuel or chemicals.

  • The total weight of an organism before any meat processing.

  • low- and middle-income countries

  • liquefied petroleum gas

  • land use change

  • A measure of the amount of light produced by a light source per energy input.

  • live weight

  • Mobility as a Service

  • marginal abatement cost curve

  • Livestock grazing practices that strategically manage livestock density, grazing intensity, and timing. Also called improved grazing, these practices have environmental, soil health, and climate benefits, including enhanced soil carbon sequestration.

  • Intertidal coastal wetlands with salt-tolerant trees and shrubs found in tropical and subtropical regions.

  • A tool to measure and compare the financial cost and abatement benefit of individual actions based on the initial and operating costs, revenue, and emission reduction potential.

  • Periods of unusually warm ocean temperatures that typically last from days to months and can affect large areas of the ocean.

  • Defined by the International Union for Conservation of Nature as: "A clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values." References to PAs here also include other effective area-based conservation measures defined by the IUCN. 

  • The transfer of economic activity or environmental impact from one area to another as a result of conservation activities, often having the effect of reducing or offsetting intended benefits.

  • The transfer of economic activity or environmental impact from one location to another as a result of conservation activities, often having the effect of reducing or offsetting intended benefits.

  • A facility that receives recyclable waste from residential, commercial, and industrial sources; separates, processes, and prepares them; and then sells them to manufacturers for reuse in new products.

  • A measure of energy equivalent to the energy delivered by one million watts of power over one hour.

  • A greenhouse gas with a short lifetime and high GWP that can be produced through a variety of mechanisms including the breakdown of organic matter.

  • A measure of mass equivalent to 1,000 kilograms (~2,200 lb), also known as tonne.

  • million hectares

  • The natural process by which microbes convert matter to energy, often producing CO₂ or other GHGs as a byproduct.

  • Soils mostly composed of inorganic materials formed through the breakdown of rocks. Most soils are mineral soils, and they generally have less than 20% organic matter by weight.

  • A localized electricity system that independently generates and distributes power. Typically serving limited geographic areas, mini-grids can operate in isolation or interconnected with the main grid.

  • Reduce adverse impact of

  • A reduction in adverse impact

  • megajoule or one million joules

  • Digital platform that integrates transport modes such as public transit, carpooling, and bike sharing into a single service, allowing users to plan, book, and pay for multimodal trips through one application.

  • Percent of trips made by different passenger and freight transportation modes.

  • A condition of being diseased, unhealthy, or injured.

  • Marine Protected Area

  • materials recovery facility

  • Municipal solid waste

  • megaton or million metric tons

  • Materials discarded from residential and commercial sectors, including organic waste, glass, metals, plastics, paper, and cardboard.

  • megawatt

  • Megawatt-hour

  • micro wind turbine

  • square meter kelvins per watt (a measure of thermal resistance, also called R-value)

  • nitrous oxide

  • The enclosed housing at the top of a wind turbine tower that contains the main mechanical and electrical components of the turbine.

  • A commitment from a country to reduce national emissions and/or sequester carbon in alignment with global climate goals under the Paris Agreement, including plans for adapting to climate impacts.

  • A gaseous form of hydrocarbons consisting mainly of methane.

  • Chemicals found in nature that are used for cooling and heating, such as CO, ammonia, and some hydrocarbons. They have low GWPs and are ozone friendly, making them climate-friendly refrigerants.

  • The rate of primary production for photosynthetic organisms, excluding the carbon they respire for their own metabolic processes.

  • The rate at which photosynthetic organisms convert carbon dioxide into organic matter, minus the carbon they respire for their own metabolic processes.

  • Microbial conversion of ammonia or ammonium to nitrite and then to nitrate under aerobic conditions.

  • A group of air pollutant molecules composed of nitrogen and oxygen, including NO and NO.

  • A greenhouse gas produced during fossil fuel combustion and agricultural and industrial processes. NO is hundreds of times more potent than CO at trapping atmospheric heat, and it depletes stratospheric ozone.

  • Metals or alloys that do not contain significant amounts of iron.

  • Social welfare organizations, civic leagues, social clubs, labor organizations, business associations, and other not-for-profit organizations.

  • A material or energy source that relies on resources that are finite or not naturally replenished at the rate of consumption, including fossil fuels like coal, oil, and natural gas.

  • nitrogen oxides

  • Net primary production

  • nitrous oxide

  • The process of increasing the acidity of seawater, primarily caused by absorption of CO from the atmosphere.

  • Organisation for Economic Co-operation and Development

  • An agreement between a seller who will produce future goods and a purchaser who commits to buying them, often used as project financing for producers prior to manufacturing.

  • Waste made of plant or animal matter, including food waste and green waste.

  • Systems to connect buyers with a network of smallholder farmers to stabilize supply and demand (sometimes called "contract farming.”

  • organic waste

  • Protected area

  • Protected Area

  • A certification that verifies a metric ton of packaging waste has been recovered and is being exported for reprocessing.

  • A certification that verifies a metric ton of packaging waste has been recovered and reprocessed.

  • Productive use of wet or rewetted peatlands that does not disturb the peat layer, such as for hunting, gathering, and growing wetland-adapted crops for food, fiber, and energy.

  • A legally protected area that lacks effective enforcement or management, resulting in minimal to no conservation benefit.

  • Airborne particles composed of solids and liquids.

  • A measure of transporting one passenger over a distance of one kilometer.

  • Incentive payments to landowners or managers to conserve natural resources and promote healthy ecological functions or ecosystem services.

  • Small, hardened pieces of plastic made from cooled resin that can be melted to make new plastic products.

  • Transitional zone between urban and rural areas that combines features of both such as housing, farms, lower-density development, and mixed land uses.

  • The longevity of any greenhouse gas emission reductions or removals. Solution impacts are considered permanent if the risk of reversing the positive climate impacts is low within 100 years.

  • Packaging waste export recovery note

  • High-efficiency solar cells with a traditional silicon base and a thin-film perovskite layer on top that allows the combined cell to capture more energy without significantly increasing its size.

  • Advanced solar cells combining perovskite and silicon layers to capture more of the solar spectrum, achieving higher efficiency than conventional silicon cells.

  • Payments for ecosystem services

  • A mixture of hydrocarbons, small amounts of other organic compounds, and trace amounts of metals used to produce products such as fuels or plastics.

  • Per- and polyfluoroalkyl substances, a class of synthetic chemicals that do not degrade easily in the environment. They can pollute the environment and can have negative impacts on human health.

  • A measure of the acidity (pH<7) or alkalinity (pH>7) of a solution.

  • Reduce the use of a material or practice over time.

  • Eliminate the use of a material or practice over time.

  • Plug-in hybrid electric car

  • Private, national, or multilateral organizations dedicated to providing aid through in-kind or financial donations.

  • A chemical or material that initiates or accelerates a chemical reaction when exposed to light without being consumed.

  • An atmospheric reaction among sunlight, VOCs, and nitrogen oxide that leads to ground-level ozone formation. Ground-level ozone, a component of smog, harms human health and the environment.

  • The process by which certain materials, such as those in solar cells, convert sunlight into electricity by releasing electrons.

  • The process by which sunlight is converted into electricity. When light hits certain materials, such as those in solar panels, it mobilizes electrons, creating an electric current.

  • A family of synthetic organic compounds used to make plastics softer, more flexible, and durable. They are added to a wide range of plastics for consumer and industrial uses.

  • polyisocyanurate

  • The adjustment of turbine blade angles around their long axis in which a control system rotates blades slightly forward or backward to regulate wind capture and optimize electricity generation.

  • passenger kilometer

  • particulate matter

  • Particulate matter 2.5 micrometers or less in diameter that can harm human health when inhaled.

  • Elected officials and their staff, bureaucrats, civil servants, regulators, attorneys, and government affairs professionals.

  • System in a vehicle that generates power and delivers it to the wheels. It typically includes an engine and/or motor, transmission, driveshaft, and differential.

  • Purchase Power Agreement.

  • Purchase Power Agreements

  • Parts per million

  • People who most directly interface with a solution and/or determine whether the solution is used and/or available. 

  • A chemical reaction that creates a solid from a solution.

  • A substance that is the starting material for a chemical reaction that forms a different substance.

  • Extraction of naturally occurring resources from the Earth, including mining, logging, and oil and gas refining. These resources can be used in raw or minimally processed forms to produce materials.

  • The process of converting inorganic matter, including carbon dioxide, into organic matter (biomass), primarily by photosynthetic organisms such as plants and algae.

  • Packaging waste recovery note

  • Defined by the International Union for the Conservation of Nature as "A clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values". References to PAs here also include other effective area-based conservation measures defined by the IUCN. 

  • A process that separates and breaks down wood and other raw materials into fibers that form pulp, the base ingredient for making paper products.

  • polyurethane

  • Long-term contract between a company (the buyer) and a renewable energy producer (the seller).

  • Long-term contracts between a company (the buyer) and a renewable energy producer (the seller).

  • photovoltaic

  • Petawatt-hour, equal to 1 billion MWh

  • research and development

  • An atom, molecule, or ion that contains at least one unpaired valence electron, making it highly reactive and often short-lived.

  • A situation in which improvements in efficiency or savings lead to consumers increasing consumption, partially or fully offsetting or exceeding the emissions or cost benefits.

  • renewable energy certificate

  • Chemical or mixture used for cooling and heating in refrigeration, air conditioning, and heat pump equipment. Refrigerants absorb and release heat as they move between states under changing pressure.

  • The amount of refrigerant needed for a particular refrigeration, air conditioning, or heat pump system.

  • A group of approaches to farming and ranching that emphasizes enhancing the health of soil by restoring its carbon content and providing other benefits to the farm and surrounding ecosystem.

  • A solution that can increase the beneficial impact of another solution through increased effectiveness, lower costs, improved adoption, enhanced global climate impact, and/or other benefits to people and nature.

  • A material or energy source that relies on naturally occuring and replenishing resources such as plant matter, wind, or sunlight.

  • A market-based instrument that tracks ownership of renewable energy generation.

  • The moldable form of raw plastic material, created by melting down waste or virgin plastics and serving as the building block for creating new plastic goods.

  • The process of moving items from end users (e.g., consumers) back to the sellers or manufacturers to reuse, recycle, or dispose of. This can include transportation, cleaning, sorting, and more.

  • The risk that removed or stored carbon can be released into the atmosphere. Lower reversibility means the carbon is more securely stored.


     

  • Hiring a vehicle to take a passenger or passengers to a particular destination.

  • U.N. treaties to combat climate change, biodiversity loss, and desertification. They include the U.N. Framework Convention on Climate Change (UNFCCC), the Convention on Biological Diversity (CBD), and the U.N. Convention to Combat Desertification (UNCCD).

  • A class of animals with complex stomachs that can digest grass. Most grazing livestock are ruminants including cows, sheep, and goats along with several other species.

  • sustainable aviation fuel

  • A wetland ecosystem regularly flooded by tides and containing salt-tolerant plants, such as grasses and herbs.

  • Intertidal coastal wetlands with salt-tolerant plants.

  • An ecosystem characterized by low-density tree cover that allows for a grass subcanopy.

  • Very large or small numbers are formatted in scientific notation. A positive exponent multiplies the number by powers of ten; a negative exponent divides the number by powers of ten.

  • Seasonal coefficient of performance

  • Sustainable Development Goals

  • Average units of heat energy released for every unit of electrical energy consumed, used to measure heat pump efficiency.

  • A single pane window (glass and frame) added to an existing single-glazed window, converting the unit into double glazing, with each pane independently operable.

  • A practice in which multiple utility companies own and operate high-voltage power lines, sharing both costs and benefits.

  • A window consisting of one glass pane without any additional insulating layers.

  • Small-scale family farmers and other food producers, often with limited resources, usually in the tropics. The average size of a smallholder farm is two hectares (about five acres).

  • Devices that control indoor temperature according to user-defined schedules or conditions.

  • soil organic carbon

  • The process of using direct, real-world observations to verify, validate, and/or improve data and models about social systems, often using in-person observations in the field.

  • Carbon stored in soils, including both organic (from decomposing plants and microbes) and inorganic (from carbonate-containing minerals).

  • Carbon stored in soils in organic forms (from decomposing plants and microbes). Soil organic carbon makes up roughly half of soil organic matter by weight.

  • Biologically derived matter in soils, including living, dead, and decayed plant and microbial tissues. Soil organic matter is roughly half carbon on a dry-weight basis.

  • A measure of the intensity of solar radiant energy on a surface, measured in watts per square meter (W/m2) or power per unit area.

  • Reducing global warming by increasing how much of the sun's radiation is reflected back to space and/or decreasing how much of the Earth's radiative heat is trapped in the atmosphere. 

  • A material's ability to reflect solar radiation incident on its surface, often reported as a fraction or percentage.

  • soil organic matter

  • A substance that takes up another liquid or gas substance, either by absorbtion or adsorption.

  • sulfur oxides

  • sulfur dioxide

  • The rate at which a climate solution physically affects the atmosphere after being deployed. At Project Drawdown, we use three categories: emergency brake (fastest impact), gradual, or delayed (slowest impact).

  • Climate regions between latitudes 23.4° to 35° above and below the equator characterized by warm summers and mild winters.

  • A polluting gas produced primarily from burning fossil fuels and industrial processes that directly harms the environment and human health.

  • A group of gases containing sulfur and oxygen that predominantly come from burning fossil fuels. They contribute to air pollution, acid rain, and respiratory health issues.

  • Processes, people, and resources involved in producing and delivering a product from supplier to end customer, including material acquisition.

  • Sport utility vehicle

  • A mixture of hydrogen, carbon monoxide, and other gases, used to produce chemicals like ammonia and methanol, or as a synthetic fuel made from non-fossil feedstocks, including biomass and waste.

  • metric ton

  • metric tons

  • Technology developers, including founders, designers, inventors, R&D staff, and creators seeking to overcome technical or practical challenges.

  • Climate regions between 35° to 50° above and below the equator characterized by moderate mean annual temperatures and distinct seasons, with warm summers and cold winters.

  • A measure of energy equivalent to the energy delivered by one trillion watts of power over one hour.

  • trifluoroacetic acid

  • trifluoroacetic acid

  • A measurement indicating the ability of a material to release heat after it has been absorbed.

  • A measure of how well a material prevents heat flow, often called R-value or RSI-value for insulation. A higher R-value means better thermal performance.

  • A measure of the rate of heat flow or heat transfer through a material or building component. A lower U-value means better thermal performance.

  • Individuals with an established audience for their work, including public figures, experts, journalists, and educators.

  • Charges for disposal of materials paid to facility operators. Fees can be charged per ton of waste disposed or based on economic indicators such as the Consumer Price Index.

  • A solar PV systems with panels that move automatically to follow the sun’s path, maximizing energy capture and improving efficiency over fixed systems.

  • A window consisting of three panes of glass separated by two insulating inert gas-filled layers, providing more heat flow resistance than single or double glazing.

  • Low-latitude (23.4°S to 23.4°N) climate regions near the Equator characterized by year-round high temperatures and distinct wet and dry seasons.

  • Terawatt, equal to 1,000 gigawatts

  • terawatt-hour

  • United Nations

  • United Nations Environment Programme

  • U.S. Composting Council

  • Self-propelled machine for transporting passengers or freight on roads.

  • A measure of one vehicle traveling a distance of one kilometer.

  • How easily and reliably a carbon‑removal claim can be measured and independently confirmed as accurate; part of measurement, reporting and verification (MRV) for carbon removal.

  • Aerobic decomposition of organic waste by earthworms and microorganisms.

  • vehicle kilometer

  • volatile organic compound

  • Gases made of organic, carbon-based molecules that are readily released into the air from other solid or liquid materials. Some VOCs are greenhouse gases or can harm human health.

  • watt (a measure of power or energy transfer.)

  • Watts per square meter Kelvin

  • A thin, flat slice of silicon cut from an ingot and processed to create individual solar cells that convert sunlight into electricity.

  • Landscape waste, storm debris, wood processing residues, and recovered post-consumer wood.

  • A framework for waste management that ranks options by their sustainability: 1) prevent (do not purchase unnecessary waste), 2) reduce, 3) reuse, 4) recycle, 5) recover, 6) dispose.

  • A measure of how much free water is available for microbes to use. It ranges from 0 (completely dry) to 1 (pure water), and low values (<0.60) indicate conditions too dry for microbes to function.

  • A measure of power equal to one joule per second.

  • World Conservation Monitoring Centre

  • Using strategies such as insulation, air sealing, ventilation, and moisture control to upgrade a building’s exterior structure, making indoors more comfortable and energy efficient.

  • Aerobic decomposition of organic waste in long, narrow rows called windrows. Windrows are generally twice as long as they are wide.

  • A subset of forest ecosystems that may have sparser canopy cover,  smaller-stature trees, and/or trees characterized by basal branching rather than a single main stem.

  • extruded polystyrene

  • The rotation of the nacelle (the enclosed housing at the top of a wind turbine tower that contains the main mechanical and electrical components of the turbine) so that the rotor blades are always facing directly into the wind.

  • year-over-year

  • year