Vertical farms are facilities that grow crops indoors, vertically stacking multiple layers of plants and providing controlled conditions using artificial light, indoor heating and cooling systems, humidity controls, water pumps, and advanced automation systems. In theory, vertical farms could reduce the need to clear more agricultural land and the distance food travels to market. However, because vertical farms are so energy and material intensive, and food transportation emissions are a small fraction of the overall carbon footprint of food, vertical farms do not reduce emissions overall. We conclude that vertical farms are “Not Recommended” as an effective climate solution.
Based on our analysis, vertical farms are not an effective climate solution. The tremendous energy use and embodied emissions of vertical farm operations outweigh any potential savings of reducing food miles or land expansion. Moreover, the ability of vertical farms to truly scale to be a meaningful part of the global food system is extremely limited. We therefore classify this as “Not Recommended” as an effective climate solution.
| Plausible | Could it work? | No |
|---|---|---|
| Ready | Is it ready? | Yes |
| Evidence | Are there data to evaluate it? | Yes |
| Effective | Does it consistently work? | No |
| Impact | Is it big enough to matter? | No |
| Risk | Is it risky or harmful? | No |
| Cost | Is it cheap? | No |
Vertical farms are facilities that grow crops indoors, with multiple layers of plants stacked on top of each other, using artificial lights, large heating and cooling systems, humidity controls, water pumps, and complex building automation systems. In principle, vertical farms can dramatically shrink the land “footprint” of agriculture, and this could help reduce the need for agricultural land. Moreover, by growing crops closer to urban centers, vertical farms could potentially reduce “food miles” and the emissions related to food transport.
The technology of growing some kinds of crops – especially greens and herbs – in indoor facilities is well developed, but there is no evidence to show that doing so can reduce GHG emissions compared to growing the same food on traditional farms. Theoretically, vertical farms could reduce emissions associated with agricultural land expansion and food transportation. However, the operation and construction of vertical farms require enormous amounts of energy and materials, all of which cause significant emissions. Vertical farms require artificial lighting (even with efficient LEDs, this is a considerable energy cost), heating, cooling, humidity control, air circulation, and water pumping – all of which require energy. Vertical farms could be powered by renewable sources; however, this is an inefficient method for reducing GHG emissions compared to using that renewable energy to replace fossil-fuel-powered electricity generation. Growing food closer to urban centers also does not meaningfully reduce emissions because emissions from “food miles” are only a small fraction of the life cycle emissions for most farmed foods. Recent research has found that the carbon footprint of lettuce grown in vertical farms can be 5.6 to 16.7 times greater than that of lettuce grown with traditional methods.
While vertical farms are not an effective strategy for reducing emissions, they may have some value for climate resilience and adaptation. Vertical farms offer a protected environment for crop growth and well-managed water use, and they can potentially shield plants from pests, diseases, and natural disasters. Moreover, the controlled environment can be adjusted to adapt to changing climate conditions, helping ensure continuous production and lowering the risks of crop loss.
Vertical farms use enormous amounts of energy and material to grow a limited array of food, all at significant cost. That energy and material have a significant carbon emissions cost, no matter how efficient the technology becomes. On the whole, vertical farms appear to emit far more GHGs than traditional farms do. Moreover, vertical farms are expensive to build and operate, and are unlikely to play a major role in the world’s food system. At present, they are mainly used to grow high-priced greens, vegetables, herbs, and cannabis, which do not address the tremendous pressure points in the global food system to feed the world sustainably. There are also concerns about the future of the vertical farming business. While early efforts were funded by venture capital, vertical farming has struggled to become profitable, putting its future in doubt.
Blom, T. et al.., 2022. The embodied carbon emissions of lettuce production in vertical farming, greenhouse horticulture, and open-field farming in the Netherlands. Journal of Cleaner Production, 377, 134443. https://www.sciencedirect.com/science/article/pii/S095965262204015X
Foley, J.A., 2018. No, Vertical Farms Won’t Feed the World, Medium.
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The buzz around indoor farms and artificial lighting makes no sense, Michaell Hamm, The Guardian, 2015.
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The vertical farming scam, Stan Cox, Counterpunch, 2012. https://www.counterpunch.org/2012/12/11/the-vertical-farming-scam/
Enough with the vertical farming fantasies: They are still too many unanswered questions about the trendy practice, Salon. https://www.salon.com/2016/02/17/enough_with_the_vertical_farming_partner/
The Vertical Farming Bubble is Finally Popping, Fast Company, 2023.
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Feed additives can reduce enteric methane production in ruminant livestock, such as cattle, goats, and sheep. Most feed additive compounds are still being researched to determine their efficacy and safety; however, at least one product, 3-NOP (3-nitrooxypropanol), has been shown to be effective, has recently been approved for use in several countries, and has experienced some early adoption. However, because of cost and the need to be administered daily, the use of feed additives is currently limited to confined ruminants in high-income countries and is not feasible for the majority of global ruminant livestock. Based on these limitations and current levels of adoption, we conclude that Use Feed Additives is “Worth Watching.”
Based on our analysis, feed additives are a promising technology that could yield globally meaningful reductions in methane emissions. A few, including 3-NOP, are just on the threshold of commercial adoption and may be widely used by confined ruminant producers in the coming years. The current use of feed additives is low, and the effectiveness of most feed additive compounds is not well-documented. Consequently, wide-scale adoption is largely confined to confined livestock in high-income countries. Based on our assessment, Use Feed Additives is “Worth Watching."
| Plausible | Could it work? | Yes |
|---|---|---|
| Ready | Is it ready? | No |
| Evidence | Are there data to evaluate it? | Yes |
| Effective | Does it consistently work? | Yes |
| Impact | Is it big enough to matter? | Yes |
| Risk | Is it risky or harmful? | No |
| Cost | Is it cheap? | Yes |
Feed additives are a diverse group of natural and synthetic compounds that, when fed daily, can reduce enteric methane production in ruminant livestock, including cattle, sheep, and goats. Enteric methane from livestock is the source of 21% of humanity’s methane emissions, or 2.9 Gt CO₂‑eq/yr. Feed additives reduce enteric methane production by suppressing the activity of microbes in the digestive system. 3-NOP (3-nitrooxypropanol) is a synthetic that inhibits an enzyme involved in enteric methane production.
More than 170 different feed additives have been developed and tested so far, but only a few of them have been studied enough to offer predictable outcomes and proper doses. Methane reductions from these well-studied additives typically range from 10-30%. The feed additive 3-NOP, the first compound approved for commercial use, reduces enteric methane by an average of 32.5%. A second feed additive derived from active compounds found in Asparagopsis seaweed has shown promising results in some studies and has recently received regulatory approval in two countries. In addition, because different feed additives use different mechanisms to suppress enteric methane production, it’s possible that multiple additives can be used together to achieve greater methane reductions. The great majority of other additives are not yet ready for widespread adoption due to a lack of understanding of effectiveness, side effects on cattle and humans who consume milk from treated cattle, and other concerns.
Ruminants are a major source of methane emissions, yet ruminant meat and dairy products are in high demand. Therefore, any strategy that can reduce methane emissions per kilogram of meat or milk is potentially very valuable and, if broadly adopted, could yield globally meaningful reductions in methane emissions (>0.1 Gt CO₂‑eq per year). The feed additive 3-NOP, first approved for commercial use in two countries in 2021, is now legal in 55 countries. Research on other feed additives is active and generally well-supported with funding from philanthropic and investment sources. Although current use of feed additives is very low, successful research and pilot studies, increasing regulatory approvals, and strong positive interest from the livestock industry suggest that wider-scale adoption of this emissions reduction technology could occur quickly. In addition to potential emissions reduction benefits, some additives offer other benefits such as increased productivity and parasite control.
Because they must be fed daily as a supplement to a concentrated feed, use of feed additives is limited to ruminants managed under confined conditions. Most of the billions of ruminant animals today are raised or managed in extensive grazing or pastoralist systems, often in small herds in remote areas. This makes use of feed additives infeasible, although some research is underway to develop methane-reducing compounds that could be added to water troughs instead of to feed. Feed additives are also costly. Though they may be cost-effective in terms of dollars per ton of CO₂‑eq reduced, the cost of additives themselves would likely be prohibitive for smallholders and pastoralists in low-income countries. These limitations mean that feed additives, as currently under development, are only suitable for a subset of total ruminant livestock – those that are raised in confinement systems in wealthy countries. The great majority of feed additives are not yet ready for widespread adoption due to a lack of understanding of effectiveness, side effects on cattle and humans who consume milk from treated cattle, and other concerns. There are also other challenges, including regulatory issues, public acceptance, and effects on livestock and human health. There is also concern that feed additives could be used to divert attention from the importance of reducing ruminant meat and milk products in the diets of wealthy countries and reducing food waste of ruminant products.
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We define the Deploy Silvopasture solution as the adoption of agroforestry practices that add trees to grazing land, including planted pastures and natural rangelands. (Note that this solution does NOT include creating forested grazing land by thinning existing forest; this is a form of deforestation and not desirable in terms of climate.) Some silvopastures are open savannas, while others are dense, mature tree plantations. The trees may be planted or managed to naturally regenerate. Some silvopasture systems have been practiced for thousands of years, while others have been recently developed. All provide shade to livestock; in some systems, the trees feed livestock, produce timber or crops for human consumption, or provide other benefits.
In silvopasture systems, trees are planted or allowed to naturally regenerate on existing pasture or rangeland. Tree density is generally low, allowing sunlight through for good forage growth.
Silvopasture has multiple climate impacts, though carbon sequestration is the only one which has been thoroughly studied across all climates and sub-practices.
Silvopasture sequesters carbon in both soil and woody biomass. Carbon sequestration rates are among the highest of any farming system (Toensmeier, 2017). The lifetime accumulation of carbon in both soils and biomass is higher than for managed grazing alone (Montagnini et al., 2019; Nair et al., 2012).
Silvopasture can also reduce GHG emissions, though not in every case. We do not include emissions reductions in this analysis.
Conversion from pasture to silvopasture slightly increases capture and storage of methane in soils (Bentrup and Shi, 2024). In addition, in fodder subtypes of silvopasture systems, ruminant livestock consume tree leaves or pods. Many, but not all, of the tree species used in these systems have tannin content that reduces emissions of methane from enteric fermentation (Jacobsen et al., 2019).
Some subtypes of silvopasture reduce nitrous oxide emissions from manure and urine, as grasses and trees capture nitrogen that microbes would otherwise convert to nitrous oxide. There are also reductions to nitrous oxide emissions from soils: 76–95% in temperate silvopastures and 16–89% in tropical-intensive silvopastures (Ansari et al., 2023; Murguietio et al., 2016).
Many silvopasture systems increase productivity of milk and meat. Yield increases can reduce emissions from deforestation by growing more food on existing farmland, but in some cases can actually worsen emissions if farmers clear forests to adopt the profitable practice (Intergovernmental Panel on Climate Change [IPCC], 2019). The yield impact of silvopasture varies with tree density, climate, system type, and whether the yields of other products (e.g., timber) are counted as well (Rojas et al., 2022).
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Zeppetello, L. R. V., Cook-Patton, S. C., Parsons, L. A., Wolff, N. H., Kroeger, T., Battisti, D. S., ... & Masuda, Y. J. (2022). Consistent cooling benefits of silvopasture in the tropics. Nature communications, 13(1), 708. https://doi.org/10.1038/s41467-022-28388-4
Eric Toensmeier
Ruthie Burrows, Ph.D.
Yusuf Jameel, Ph.D.
Daniel Jasper
Aiyana Bodi
Hannah Henkin
Ted Otte
Paul West, Ph.D.
We found a median carbon sequestration rate of 9.81 t CO₂/ha/yr (Table 1). This is based on an above-ground biomass (tree trunks and branches) accumulation rate of 6.43 t CO₂/ha/yr and a below-ground biomass (roots) accumulation rate of 1.61 t CO₂/ha/yr using a root-to-shoot ratio of 0.25 (Cardinael et al., 2019). These are added to the soil organic carbon sequestration rate of 1.76 t CO₂/ha/yr to create the combined total.
Table 1. Carbon sequestration.
Unit: t CO₂-eq/ha/yr
| 25th percentile | 4.91 |
| mean | 14.70 |
| median (50th percentile) | 9.81 |
| 75th percentile | 20.45 |
100-yr basis
Reductions in nitrous oxide and methane and sustainable intensification impacts are not yet quantifiable to the degree that they can be used in climate mitigation projections.
Because baseline grazing systems are already extensive and well established, we assumed there is no cost to establish new baseline grazing land. In the absence of global data sets on costs and revenues of grazing systems, we used a global average profit per hectare of grazing land of US$6.28 from Damnnia et al. (2023).
Establishment costs of silvopasture vary widely. We found the cost to establish one hectare of silvopasture to be US$1.06–4,825 (Dupraz & Liagre, 2011; Lee et al., 2011). Reasons for this wide range include the low cost of natural regeneration and the broad range in tree density depending on the type of system. We collected costs by region and used a weighted average to obtain a global net net cost value of US$424.20.
Cost and revenue data for silvopasture were insufficient. However, data on the impact on revenues per hectare are abundant. Our analysis found a median 8.7% increase in per-hectare profits from silvopasture compared with conventional grazing, which we applied to the average grazing value to obtain a net profit of US$6.82/ha. This does not reflect the very high revenues of silvopasture systems in some countries.
We calculated cost per t CO₂‑eq sequestered by dividing net net cost/ha by total CO₂‑eq sequestered/ha.
Table 2. Cost per unit of climate impact.
Unit: 2023 US$/t CO₂-eq
| median | $43.25 |
100-yr basis & 20-yr basis are the same.
There is not enough information available to determine a learning curve for silvopasture. However, anecdotal evidence showed establishment costs decreasing as techniques for broadscale mechanized establishment were developed in Australia and Colombia (Murguietio et al., 2016; Shelton et al., 2021).
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 gradual, emergency brake, or delayed.
Deploy Silvopasture is a DELAYED climate solution. It works more slowly than nominal or emergency brake solutions. Delayed solutions can be robust climate solutions, but it’s important to recognize that they realize their full potential for some time.
Living biomass and soil organic matter only temporarily hold carbon (decades to centuries for soil organic matter, and for the life of the tree or any long-lived products made from its wood in the case of woody biomass). Sequestered carbon in both soils and biomass is vulnerable to fire, drought, long-term shifts to a drier precipitation regime, and other climate change impacts, as well as to a return to the previous farming or grazing practices. Such disturbances can cause carbon to be re-emitted to the atmosphere (Lorenz & Lal, 2018).
Like all upland, terrestrial agricultural systems, over the course of decades, silvopastures reach saturation and net sequestration slows to nearly nothing (Lorenz & Lal, 2018).
Lack of data on the current adoption of silvopasture is a major gap in our understanding of the potential of this solution. One satellite imaging study found 156 million ha of grazing land with over 10 t C/ha in above-ground biomass, which is the amount that indicates more than grass alone (Chapman et al., 2019). However, this area includes natural savannas, which are not necessarily silvopastures, and undercounts the existing 15.1 million ha of silvopasture known to be present in Europe (den Herder et al., 2017).
Sprenkle-Hippolite et al. (2024) estimated a current adoption of 141.4 Mha, or 6.0% of grazing land (Table 3). We have chosen this more recent figure as the best available estimate of current adoption.
Table 3. Current (2023) adoption level.
Unit: million ha
| mean | 141.4 |
There is little quantifiable information reported about silvopasture adoption.
Grazing is the world’s largest land use at 2,986 million ha (Mehrabi et al., 2024). Much grazing land is too dry for trees, while other grasslands that were not historically forest or savanna should not be planted with trees in order to minimize water use and protect grassland habitat (Dudley et al., 2020). Three studies estimated the total potential area suitable for silvopasture (including current adoption).
Lal et al. (2018) estimated the technical potential for silvopasture adoption at 550 Mha.
Chapman et al. (2019) estimated the suitable area for increased woody biomass on grazing land as 1,890 Mha.
Sprenkle-Hippolite (2024) assessed the maximum area of grazing land to which trees could be added without reducing livestock productivity. They calculated a total of 1,589 Mha, or 67% of global grazing land (Table 4). To our knowledge, this is the most accurate estimate available.
Table 4. Adoption ceiling.
Unit: ha installed
| 25th percentile | 1,069,000,000 |
| mean | 1,343,000,000 |
| median (50th percentile) | 1,588,000,000 |
| 75th percentile | 1,739,000,000 |
Unit: % of grazing land
| 25th percentile | 45 |
| mean | 36 |
| median (50th percentile) | 53 |
| 75th percentile | 58 |
In our Achievable – High scenario, global silvopasture starts at 141.4 million ha and grows at the Colombian Nationally Determined Contribution growth rate of 6.5%/yr. This would provide the high end of the achievable potential at 206.3 million ha by 2030, of which 64.9 million ha are newly adopted (Table 5). For the Achievable – Low scenario, we chose 1/10 of Colombia’s projected growth rate. This would provide 147.0 million ha of adoption by 2030, of which 5.6 million ha are new.
Few estimates of the global adoption potential of silvopasture are available, and even those for the broader category of agroforestry are rare due to the lack of solid data on current adoption and growth rates (Shi et al., 2018; Hart et al., 2023). The IPCC estimates that, for agroforestry overall, 19.5% of the technical potential is economically achievable (IPCC AR6 WG3, 2022). Applying this rate to Sprenkle-Hippolite’s estimated 1,588 million ha technical potential yields an achievable potential of 310 million ha of convertible grazing land.
Our high adoption rate reaches 13% of the adoption ceiling by 2030. This suggests that silvopasture represents a large but relatively untapped potential that will require aggressive policy action and other incentives to spur scaling.
Table 5. Range of achievable adoption levels.
Unit: million ha
| Current Adoption | 141.4 |
| Achievable – Low | 147.0 |
| Achievable – High | 206.3 |
| Adoption Ceiling | 1,588.0 |
Unit: million ha
| Current Adoption | 0.00 |
| Achievable – Low | 5.6 |
| Achievable – High | 64.9 |
| Adoption Ceiling | 1,447.4 |
Carbon sequestration continues only for a period of decades; because silvopasture is an ancient practice with some plantings centuries old, we could not assume that previously adopted hectares continue to sequester carbon indefinitely. Thus, we make the conservative choice to calculate carbon sequestration only for newly adopted hectares.
Carbon sequestration impact is 0.00 Gt CO₂‑eq/yr for current adoption, 0.05 for Achievable – Low, 0.64 for Achievable – High, and 14.20 for our Adoption Ceiling.
Table 6. Climate impact at different levels of adoption.
Unit: Gt CO₂-eq/yr
| Current Adoption | 0.00 |
| Achievable – Low | 0.05 |
| Achievable – High | 0.64 |
| Adoption Ceiling | 14.20 |
100-yr basis, New adoption only
Lal et al. (2018) estimated a technical global carbon sequestration potential of 0.3–1.0 Gt CO₂‑eq/yr. Sprenkle-Hyppolite et al. (2024) estimated a silvopasture technical potential of 1.4 Gt CO₂‑eq/yr, which assumes a tree density of 2–6 trees/ha, which is substantially lower than typical silvopasture. For agroforestry overall (including silvopasture and other practices), the IPCC estimates an achievable potential of 0.8 Gt CO₂‑eq/yr and a technical potential of 4.0 Gt CO₂‑eq/yr.
While evidence on the impact of silvopasture on yields is mixed, this practice can improve food security by diversifying food production and income sources (Bostedt et al., 2016; Smith et al., 2022). In pastoralists in Kenya, Bostedt et al. (2016) found that agroforestry practices were associated with increased dietary diversity, an important aspect of food and nutrition security. Diverse income streams can mediate household food security during adverse conditions, such as droughts or floods, especially in low- and middle-income countries (de Sherbinin et al., 2007; Di Prima et al., 2022; Frelat et al., 2016).
Silvopasture can also increase and diversify farmer income. Tree fruit and timber often provide additional income for ranchers. A study in the southern United States showed that silvopasture systems generated 10% more income than standalone cattle production (Husak and Grado et al., 2002). A more comprehensive analysis across the eastern United States (Greene et al., 2023) found that virtually all silvopasture systems assessed had a positive 20- and 30-yr internal rate of return (IRR). For some systems, the 30-yr IRR can be >15% (Greene et al., 2023).
By providing shade, silvopasture systems reduce heat stress experienced by livestock. Heat stress for cattle begins at 30 °C or even lower in some circumstances (Garrett et al., 2004). In the tropics, the cooling effect of integrating trees into a pastoral system is 0.32–2.4 °C/t of woody carbon added/ha (Zeppetello et al., 2022). Heifers raised in silvopasture systems had higher body mass and more optimal body temperature than those raised in intensive rotational grazing systems (Lemes et al., 2021). Improvement in livestock physiological conditions probably results from access to additional forage, increased livestock comfort, and reduced heat stress in silvopastoral systems. Silvopasture is highly desirable for its improvements to animal welfare (Goracci & Camilli, 2024).
Trees boost habitat availability, enhance landscape connectivity, and aid in forest regeneration and restoration. In most climates they provide a major boost to biodiversity compared with pasture alone (Smith et al., 2022; Pezo et al., 2018).
Perennials in silvopasture systems could reduce runoff and increase water infiltration rates relative to open rangelands (Smith et al., 2022; Pezo et al., 2018). This increases the resilience of the system during drought and high heat.
Some of the tree and forage species used in silvopastures are invasive in certain contexts. For example, river tamarind (Leucaena leucocephala) is a centerpiece in intensive silvopasture in Latin America, where it is native, but also in Australia, where it is not. Australian producers have developed practices to limit or prevent its spread (Shelton et al., 2021).
Livestock can damage or kill young trees during establishment. Protecting trees or excluding grazing animals during this period increases costs (Smith et al., 2022).
Poorly designed tree layout can make herding, haying, fencing, and other management activities more difficult. Tree densities that are too high can reduce livestock productivity (Cadavid et al., 2020).
Silvopasture represents a way to produce some ruminant meat and dairy in a more climate-friendly way. This impact can contribute to addressing emissions from ruminant production, but only as part of a program that strongly emphasizes diet change and food waste reduction.
Forms of silvopasture that increase milk and meat yields can reduce pressure to convert undeveloped land to agriculture.
Silvopasture is a technique for restoring farmland.
Silvopasture is a form of savanna restoration.
Silvopasture and forest restoration can compete for the same land.
Silvopasture is a kind of agroforestry, though in this iteration of Project Drawdown “Deploy Agroforestry” refers to crop production systems only. With that said, some agroforestry systems integrate both crops and livestock with the trees, such as the widespread parkland systems of the African Sahel.
1 ha converted from grazing land to silvopasture
CO₂
Solutions that improve ruminant production could undermine the argument for reducing ruminant protein consumption in wealthy countries.
Certain silvopasture systems reduce per-hectare productivity of meat and milk, even if overall productivity increases when the yields of timber or food from the tree component are included. For example, silvopasture systems that are primarily focused on timber production, with high tree densities, will have lower livestock yields than pasture alone - though they will have high timber yields.
The costs of establishment are much higher than those of managed grazing. There is also a longer payback period (Smith et al., 2022). These limitations mean that secure land tenure is even more important than usual, to make adoption worthwhile (Poudel et al., 2024).
Silvopasture is primarily appropriate for grazing land that receives sufficient rainfall to support tree growth. While it can be implemented on both cropland and grassland, if adopted on cropland, it will reduce food yield because livestock produce much less food per hectare than crops. In the humid tropics, a particularly productive and high-carbon variation called intensive silvopasture is an option. Ideally, graziers will have secure land tenure, though pastoralist commons have been used successfully.
Areas too dry to establish trees (<450 mm annual precipitation) are not suitable for silvopasture by tree planting, but regions that can support natural savanna may be suitable for managed natural regeneration.
Most silvopasture today appears in sub-Saharan Africa (Chapman et al., 2019), though this may reflect grazed natural savannas rather than intentional silvopasture. This finding neglects well-known systems in Latin America and Southern Europe.
Chapman et al. (2019) listed world grasslands by their potential to add woody biomass. According to their analysis, the countries with the greatest potential to increase woody biomass carbon in grazing land are, in order: Australia, Kazakhstan, China, the United States, Mongolia, Iran, Argentina, South Africa, Sudan, Afghanistan, Russia, and Mexico. Tropical grazing land accounts for 73% of the potential in one study. Brazil, China, and Australia have the highest areas, collectively accounting for 37% of the potential area (Sprenkle-Hippolite 2024).
We do not present any maps for the silvopasture solution due to the uncertainties in identifying current areas where silvopasture is practiced, and in identifying current grasslands that were historically forest or savanna.
There is a high level of consensus about the carbon biosequestration impacts of silvopasture, including for the higher per-hectare sequestration rates relative to improved grazing systems alone. A handful of reviews, expert estimations, and meta-analyses have been published on the subject. These include:
Cardinael et al. (2018) assembled data by climate and region for use in the national calculations and reporting.
Chatterjee et al. (2018) found that converting from pasture to silvopasture increases carbon stocks.
Lal et al. ( 2018) estimated the technical adoption and mitigation potential of silvopasture and other practices.
Udawatta et al. (2022) provided an up- to date meta-analysis for temperate North America.
The results presented in this document summarize findings from two reviews, two meta-analyses, one expert opinion and three original studies reflecting current evidence from a global scale. We recognize this limited geographic scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions.
There is low consensus on the reduction of methane from enteric emissions, nitrous oxide from manure, and CO₂ from avoided deforestation due to increased productivity. We do not include these climate impacts in our calculations.
Until recently there was little understanding of the current adoption of silvopasture. Sprenkle-Hyppolite et al. (2024) used Delphi expert estimation to determine current adoption and technical potential. Rates of adoption and achievable potential are still largely unreported or uninvestigated. See the Adoption section for details.
Farmers on much of the world’s 1.4 billion ha of cropland grow and harvest annual crops – crops like wheat, rice, and soybeans that live for one year or less. After harvest, croplands are often left bare for the rest of the year and sometimes tilled, exposing the soil to wind and rain. This keeps soil carbon levels low and can lead to soil erosion. There are many ways to improve annual cropping to protect or enhance the health of the soil and increase soil organic matter. Project Drawdown’s Improve Annual Cropping solution is a set of practices that protects soils by minimizing plowing (no-till/reduced tillage) and maintaining continuous soil cover (by retaining crop residues or growing cover crops). This increases soil carbon sequestration and reduces nitrous oxide emissions. These techniques are commonly used in conservation agriculture, regenerative, and agro-ecological cropping systems. Other annual cropping practices with desirable climate impacts – including compost application and crop rotations – are omitted here due to lack of data and much smaller scale of adoption.
The Improve Annual Cropping solution incorporates several practices that minimize soil disturbance and introduce a physical barrier meant to prevent erosion to fragile topsoils. Our definition includes two of the three pillars of conservation agriculture: minimal soil disturbance and permanent soil cover (Kassam et al., 2022).
Soil organic carbon (SOC) – which originates from decomposed plants – helps soils hold moisture and provides the kinds of chemical bonding that allow nutrients to be stored and exchanged easily with plants. Soil health and productivity depend on microbial decomposition of plant biomass residues, which mobilizes critical nutrients in soil organic matter (SOM) and builds SOC. Conventional tillage inverts soil, buries residues, and breaks down compacted soil aggregates. This process facilitates microbial activity, weed removal, and water infiltration for planting. However, tillage can accelerate CO₂ fluxes as SOC is lost to oxidation and runoff. Mechanical disturbance further exposes deeper soils to the atmosphere, leading to radiative absorption, higher soil temperatures, and catalyzed biological processes – all of which increase oxidation of SOC (Francaviglia et al., 2023).
Reduced tillage limits soil disturbance to support increased microbial activity, moisture retention, and stable temperature at the soil surface. This practice can increase carbon sequestration, at least when combined with cover cropping. These effects are highly contextual, depending on tillage intensity and soil depth as well as the practice type, duration, and timing. Reduced tillage further reduces fossil fuel emissions from on-farm machinery. However, this practice often leads to increased reliance on herbicides for weed control (Francaviglia et al., 2023).
Residue retention and cover cropping practices aim to provide permanent plant cover to protect and improve soils. This can improve aggregate stability, water retention, and nutrient cycling. Farmers practicing residue retention leave crop biomass residues on the soil surface to suppress weed growth, improve water infiltration, and reduce evapotranspiration from soils (Francaviglia et al., 2023).
Cover cropping includes growth of spontaneous or seeded plant cover, either during or between established cropping cycles. In addition to SOC, cover cropping can help decrease nitrous oxide emissions and bind nitrogen typically lost via oxidation and leaching. Leguminous cover crops can also fix atmospheric nitrogen, reducing the need for fertilizer. Cover cropping can further be combined with reduced tillage for additive SOC and SOM gains (Blanco-Canqui et al., 2015; Francaviglia et al., 2023).
Improved annual cropping practices can simultaneously reduce GHG emissions and improve SOC stocks. However, there are biological limits to SOC stocks – particularly in mineral soils. Environmental benefits are impermanent and only remain if practices continue long term (Francaviglia et al., 2023).
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Avery Driscoll
Erika Luna
Megan Matthews, Ph.D.
Eric Toensmeier
Aishwarya Venkat, Ph.D.
Ruthie Burrows, Ph.D.
James Gerber, Ph.D.
Yusuf Jameel, Ph.D.
Daniel Jasper
Alex Sweeney
Aiyana Bodi
Emily Cassidy, Ph.D.
James Gerber, Ph.D.
Hannah Henkin
Zoltan Nagy, Ph.D.
Ted Otte
Paul West, Ph.D.
Based on seven reviews and meta-analyses, which collectively analyzed over 500 studies, we estimate that this solution’s SOC sequestration potential is 1.28 t CO₂‑eq/ha/yr. This is limited to the topsoil (>30 cm), with minimal effects at deeper levels (Sun et al., 2020; Tiefenbacher et al., 2021). Moreover, carbon sequestration potential isn't constant over time. The first two decades show the highest increase, followed by an equilibrium or SOC saturation (Cai, 2022; Sun et al., 2020).
The effectiveness of the Improve Annual Cropping solution heavily depends on local geographic conditions (e.g., soil properties, climate), crop management practices, cover crop biomass, cover crop types, and the duration of annual cropping production – with effects typically better assessed in the long term (Abdalla et al., 2019; Francaviglia et al., 2023; Moukanni et al., 2022; Paustian et al., 2019).
Based on reviewed literature (three papers, 18 studies), we estimated that improved annual cropping can potentially reduce nitrous oxide emissions by 0.51 t CO₂‑eq/ha/yr (Table 1). Cover crops can increase direct nitrous oxide emissions by stimulating microbial activity, but – compared with conventional cropping – lower indirect emissions allow for reduced net nitrous oxide emissions from cropland (Abdalla et al., 2019).
Nitrogen fertilizers drive direct nitrous oxide emissions, so genetic optimization of cover crops to increase nitrogen-use efficiencies and decrease nitrogen leaching could further improve mitigation of direct nitrous oxide emissions (Abdalla et al., 2019).
Table 1. Effectiveness at reducing emissions and removing carbon.
Unit: t CO₂‑eq/ha/yr
| 25th percentile | 0.29 |
| median (50th percentile) | 0.51 |
| 75th percentile | 0.80 |
Unit: t CO₂‑eq/ha/yr
| 25th percentile | 0.58 |
| median (50th percentile) | 1.28 |
| 75th percentile | 1.72 |
Unit: t CO₂‑eq/ha/yr
| 25th percentile | 0.88 |
| median (50th percentile) | 1.80 |
| 75th percentile | 2.52 |
Because baseline (conventional) annual cropping systems are already extensive and well established, we assume there is no cost to establish new baseline cropland. In the absence of global datasets on costs and revenues of cropping systems, we used data on the global average profit per ha of cropland from Damiana et al. (2023) to create a weighted average profit US$76.86/ha.
Based on 13 data points (of which seven were from the United States), the median establishment cost of the Improve Annual Cropping Solution is $329.78/ha. Nine data points (three from the United States) provided a median increase in profitability of US$86.01/ha.
The net net cost of the Improve Annual Cropping solution is US$86.01. The cost per t CO2 -eq is US$47.80 (Table 2).
Table 2. Cost per unit climate impact.
Unit: 2023 US$/t CO₂‑eq, 100-yr basis
| median | 47.80 |
We found limited information on this solution’s learning curve. A survey of farmers in Zambia found a reluctance to avoid tilling soils because of the increased need for weeding or herbicides and because crop residues may need to be used for livestock feed (Arslan et al., 2015; Searchinger et al., 2019).
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 gradual, emergency brake, or delayed.
Improve Annual Cropping is a DELAYED climate solution. It works more slowly than nominal or emergency brake solutions. Delayed solutions can be robust climate solutions, but it’s important to recognize that they realize their full potential for some time.
As with other biosequestration solutions, carbon stored in soils via improved annual cropping is not permanent. It can be lost quickly through a return to conventional agriculture practices like plowing, and/or through a regional shift to a drier climate or other human- or climate change–driven disturbances. Carbon sequestration also only continues for a limited time, estimated at 20–50 years (Lal et al., 2018)).
Kassam et al. (2022) provided regional adoption from 2008–2019. We used a linear forecast to project 2025 adoption. This provided a figure of 267.4 Mha in 2025 (Table 3).
Table 3. Current (2025) adoption level.
Unit: Mha of improved annual cropping installed
| Drawdown estimate | 267.4 |
Between 2008–2009 and 2018–2019 (the most recent data available), the cropland area under improved annual cropping practices nearly doubled globally, increasing from 10.6 Mha to 20.5 Mha at an average rate of 1.0 Mha/yr (Kassam et al., 2022), equivalent to a 9.2% annual increase in area relative to 2008–2009 levels. Adoption slowed slightly in the latter half of the decade, with an average increase of 0.8 Mha/yr- between 2015–2016 and 2018–2019, equivalent to 4.6% annual increase in area relative to 2015–2016 levels.
Median adoption is 1.11 ha/yr. The median, mean, and 25th and 75th percentiles are shown in Table 4.
Table 4. 2008–2009 to 2018–2019 adoption trend.
Unit: Mha adopted/yr
| 25th percentile | 0.54 |
| mean | 1.41 |
| median (50th percentile) | 1.11 |
| 75th percentile | 2.04 |
Griscom et al. (2017) estimate that 800 Mha of global cropland are suitable – but not yet used for – cover cropping, in addition to 168 Mha already in cover crops (Popelau and Don, 2015). We update the 168 Mha in cover crops to 267 Mha based on Kassam (2022). Griscom et al.’s estimate is based on their analysis that much cropland is unsuitable because it already is used to produce crops during seasons in which cover crops would be grown. Their estimate thus provides a maximum technical potential of 1,067 Mha (Table 5).
Table 5. Adoption ceiling.
Unit: Mha
| Adoption ceiling | 1,067 |
The 8th World Congress on Conservation Agriculture (8WCCA) set a goal to achieve adoption of improved annual cropping on 50% of available cropland by 2050 (WCCA 2021). That provides an adoption ceiling of 700 Mha – though this is not a biophysical limit.
We used the 2008–2019 data from Kassam (2022) to calculate average annual regional growth rates. From these we selected the 25th percentile as our low achievable level (Table 6).
Table 6. Range of achievable adoption levels.
Unit: Mha installed
| Current Adoption | 267.4 |
| Achievable – Low | 331.7 |
| Achievable – High | 700.0 |
| Adoption Ceiling | 1,067.0 |
Unit: Mha installed
| Current Adoption | 0.00 |
| Achievable – Low | 64.2 |
| Achievable – High | 432.6 |
| Adoption Ceiling | 868.6 |
Carbon sequestration continues only for a period of decades; because adoption of improved annual cropping was already underway in the 1970s (Kassam et al., 2022), we could not assume that previously adopted hectares continue to sequester carbon indefinitely. Thus we make the conservative choice to calculate carbon sequestration only for newly adopted hectares. We use the same conservative assumption for nitrous oxide emissions.
Combined effect is 0.0 Gt CO₂‑eq/yr for current adoption, 0.12 for Achievable – Low, 0.78 for Achievable – High, and 1.56 for our Adoption Ceiling.
Table 8. Climate impact at different levels of adoption.
Unit: Gt CO₂‑eq/yr, 100-yr basis
| Current Adoption | 0.00 |
| Achievable – Low | 0.03 |
| Achievable – High | 0.22 |
| Adoption Ceiling | 0.45 |
(from nitrous oxide)
Unit: Gt CO₂‑eq/yr, 100-yr basis
| Current Adoption | 0.00 |
| Achievable – Low | 0.08 |
| Achievable – High | 0.56 |
| Adoption Ceiling | 1.12 |
(from SOC)
Unit: Gt CO₂‑eq/yr, 100-yr basis
| Current Adoption | 0.00 |
| Achievable – Low | 0.12 |
| Achievable – High | 0.78 |
| Adoption Ceiling | 1.56 |
The soil and water benefits of this solution can lead to agricultural systems that are more resilient to extreme weather events (Mrabet et al., 2023). These agricultural systems have improved uptake, conservation, and use of water, so they are more likely to successfully cope and adapt to drought and dry conditions (Su et al., 2021). Additionally, more sustained year-round plant cover can increase the capacity of cropping systems to adapt to high temperatures and extreme rainfall (Blanco-Canqui & Francis, 2016; Martinez-Mena et al., 2020).
Increased organic matter due to improved annual cropping increases soil water holding capacity. This increases drought resilience (Su et al., 2021).
Conservation agriculture practices can reduce costs on fuel, fertilizer, and pesticides (Stavi et al., 2016). The highest revenues from improved annual cropping are often found in drier climates where higher yields are more likely. Nyagumbo et al. (2020) found that smallholder farms in sub-Saharan Africa using conservation agriculture had the highest returns on crop yields when rainfall was low. Tambo et al. (2018) found when smallholder farmers in sub-Saharan Africa jointly employed the three aspects of conservation agriculture – reduced tillage, cover crops, and crop rotation – households and individuals saw the largest income gains.
Improved annual cropping can improve food security by increasing the amount and the stability of crop yields. A meta-analysis of studies of South Asian cropping systems found that those following conservation agriculture methods had 5.8% higher mean yield than cropping systems with more conventional agriculture practices (Jat et al., 2020). Evidence supports that conservation agriculture practices especially improve yields in water scarce areas (Su et al., 2021). Nyagumbo et al. (2020) found that smallholder farmers in sub-Saharan Africa experienced reduced yield variability when using conservation agriculture practices.
Improved annual cropping can increase biodiversity below and above soils (Mrabet et al., 2023). Increased vegetation cover improves habitats for arthropods, which help with pest and pathogen management (Stavi et al., 2016).
Improved annual cropping methods can lead to improved soil health through the increased stability of soil structure, increased soil nutrients, and improved soil water storage (Francaviglia et al., 2023). This can reduce soil degradation and erosion (Mrabet et al., 2023). Additionally, more soil organic matter can lead to additional microbial growth and nutrient availability for crops (Blanco-Canqui & Francis, 2016).
Runoff of soil and other agrochemicals can be minimized through conservation agricultural practices (Jayaraman et al., 2021), reducing the amount of nitrate and phosphorus that leach into waterways and contribute to algal blooms and eutrophication (Jayaraman et al., 2021). Abdalla et al. (2019) found that cover crops reduced nitrogen leaching.
Herbicides – in place of tillage – are used in many but not all no-till cropping systems to kill (terminate) the cover crop. The large-scale use of herbicides in improved annual cropping systems can produce a range of environmental and human health consequences. Agricultural impacts can include development of herbicide-resistant weeds (Clapp, 2021).
If cover crops are not fully terminated before establishing the main crop, there is a risk that cover crop can compete with the main crop (Quintarelli et al., 2022).
Improved annual cropping has competing interactions with several other solutions related to shifting annual practices. For each of these other solutions, the Improve Annual Cropping solution can reduce the area on which the solution can be applied or the nutrient excess available for improved management.
In no-till systems, cover crops are typically terminated with herbicides, often preventing incorporation of trees depending on the type of herbicide used.
Land managed under the Improve Annual Cropping solution is not available for perennial crops.
Improved annual cropping typically reduces fertilizer demand, reducing the scale of climate impact under improved nutrient management.
Our definition of improved annual cropping requires residue retention, limiting the additional area available for deployment of reduced burning.
1 ha of cropland
CO₂, N₂O
Some studies have found that conservation tillage without cover crops can reduce soil carbon stocks in deeper soil layers. They caution against overreliance on no-till as a sequestration solution in the absence of cover cropping. Reduced tillage should be combined with cover crops to ensure carbon sequestration (Luo et al., 2010; Ogle et al., 2019; Powlson et al., 2014).
Agriculture has altered the soil carbon balance around the world, resulting in changes (mostly losses) of soil carbon. Much of the nearly 500 Gt CO2-eq lost in the last 12,000 years is now in the atmosphere in the form of CO2.
Sanderman, J. et al. (2017). The soil carbon debt of 12,000 years of human land use [Data set]. PNAS 114(36): 9575–9580. doi:10.1073/pnas.1706103114
Agriculture has altered the soil carbon balance around the world, resulting in changes (mostly losses) of soil carbon. Much of the nearly 500 Gt CO2-eq lost in the last 12,000 years is now in the atmosphere in the form of CO2.
Sanderman, J. et al. (2017). The soil carbon debt of 12,000 years of human land use [Data set]. PNAS 114(36): 9575–9580. doi:10.1073/pnas.1706103114
Adoption of this solution varies substantially across the globe. Currently, improved annual cropping practices are widely implemented in Australia and New Zealand (74% of annual cropland) and Central and South America (69%), with intermediate adoption in North America (34%) and low adoption in Asia, Europe, and Africa (1–5%) (Kassam et al., 2022), though estimates vary (see also Prestele et al., 2018). Future expansion of this solution is most promising in Asia, Africa, and Europe, where adoption has increased in recent years. Large areas of croplands are still available for implementation in these regions, whereas Australia, New Zealand, and Central and South America may be reaching a saturation point, and these practices may be less suitable for the relatively small area of remaining croplands.
The carbon sequestration effectiveness of this solution also varies across space. Drivers of soil carbon sequestration rates are complex and interactive, with climate, initial soil carbon content, soil texture, soil chemical properties (such as pH), and other land management practices all influencing the effectiveness of adopting this solution. Very broadly, the carbon sequestration potential of improved annual cropping tends to be two to three times higher in warm areas than cool areas (Bai et al., 2019; Cui et al., 2022; Lessmann et al., 2021). Warm and humid conditions enable vigorous cover crop growth, providing additional carbon inputs into soils. Complicating patterns of effectiveness, however, arid regions often experience increased crop yields following adoption of this solution whereas humid regions are more likely to experience yield losses (Pittelkow et al., 2015). Yield losses may reduce adoption in humid areas and can lead to cropland expansion to compensate for lower production.
Uptake of this solution may be constrained by spatial variation in places where cover cropping is suitable. In areas with double or triple cropping, there may not be an adequate interval for growth of a cover crop between harvests. In areas with an extended dry season, there may be inadequate moisture to grow a cover crop.
The impacts of improved annual cropping practices on soil carbon sequestration have been extensively studied, and there is high consensus that adoption of cover crops can increase carbon sequestration in soils. However, estimates of how much carbon can be sequestered vary substantially, and sequestration rates are strongly influenced by factors such as climate, soil properties, time since adoption, and how the practices are implemented.
The carbon sequestration benefits of cover cropping are well established. They have been documented in reviews and meta-analyses including Hu et al. (2023) and Vendig et al. (2023).
Relative to conventional tillage, estimates of soil carbon gains in shallow soils under no-till management include average increases of 5–20% (Bai et al., 2019; Cui et al., 2022; Kan et al., 2022). Lessmann et al. (2021) estimated that use of no-till is associated with an average annual increase in carbon sequestration of 0.88 t CO₂‑eq /ha/yr relative to high-intensity tillage.
Consensus on nitrous oxide reductions from improved annual cropping is mixed. Several reviews have demonstrated a modest reduction in nitrous oxide from cover cropping (Abdalla et al., 2019; Xing & Wang, 2024). Reduced tillage can result in either increased or decreased nitrous oxide emissions (Hassan et al., 2022).
The results presented in this document summarize findings from 10 reviews and meta-analyses reflecting current evidence at the global scale. Nonetheless, not all countries are represented. We recognize this limited geographic scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions.
