Emissions from land used to grow crops for food, animal feed, fiber, fuel and more, known as croplands, are often overlooked. But they are far from insignificant. New maps of crop emissions from a global collaboration of universities and international research institutions, led by Cornell University and Land & Carbon Lab, reveal that in 2020 alone, croplands emitted nearly 5% of global net greenhouse gas (GHG) emissions caused by human activity. That may sound small, but these emissions surpass those from global shipping and are on par with annual GHG emissions from tropical primary forest loss.

Just four crops — rice, maize (corn), wheat and oil palm — account for the majority (67%) of these emissions, even though hundreds of crops are grown worldwide. Emissions from these top-emitting crops come from the large areas of land they occupy and the way that land is managed, including the use of fertilizers, manure, burning leftover crops, and other cultivation techniques.

Clearly, these crops are essential to nourish a rising global population —  projected to reach nearly 10 billion people by 2050 —  as well as for the rapid increase in animal feed demand and for creating industrial products used in our everyday lives. At the same time, there is an opportunity to shape a more climate-smart, resource-efficient global food system, where farming plays a more significant role in addressing climate change.

A man rides a plow on farmland surrounded by white birds.
After harvest on a Sri Lanka rice field, a man plows the field. Farming practices, like plowing leftover crops back into soil can release climate-harming emissions. Photo by pilesasmiles/iStock.

Where Do Emissions from Crop Farming Come From?

Emissions from crop farming accounted for 19% of net emissions (a total of 2.5 gigatons of carbon dioxide equivalent) from the land sector in 2020, the latest year for which global maps are available.

They originate from six major sources, each linked to specific crops and agricultural management practices: Nearly all crop emissions come from draining peatlands (35%), flooding fields for rice cultivation (35%) and the use of synthetic fertilizers (23%), which together generate 93% of all emissions from crop farming.

Burning leftover crop material, incorporating crop residues into soils and spreading animal manure as fertilizer — all of which release emissions — together account for about 7% of all emissions from crop fields.

Draining peatlands exposes carbon-rich soils that have been waterlogged for centuries. When these soils dry out, the presence of oxygen triggers microbial activity that breaks down the organic matter, releasing large amounts of carbon dioxide. In contrast, flooded rice fields release methane because waterlogged soils lack oxygen, creating ideal conditions for methane-producing microbes to break down organic matter.

Degraded peatlands after they've been cleared for agricultural production.
As peatlands are cleared and drained for agricultural production, they release large amounts of carbon dioxide. In Indonesia, peatlands are often cleared to grow oil palms. Photo by RidhamSupriyanto / Shutterstock.

Compared to carbon dioxide, methane traps more than 25 times as much heat in the atmosphere over a 100-year period, making even small amounts of methane a significant contributor to climate change.

Nitrogen fertilizers also contribute emissions when excess nitrogen not used by crops is converted by soil microbes into nitrous oxide, an even more potent greenhouse gas more than 270 times more powerful as carbon dioxide.

Farming practices such as when fertilizers are applied, how crop residues are handled after harvest and how fields are irrigated play a major role in shaping a farm’s emissions profile. Two farmers growing the same crop in the same region can have different emission footprints simply because they make different choices about fertilizer, water and soil management. This variation shows that one-size-fits-all climate solutions are unlikely to be effective. Instead, reducing emissions from agriculture requires targeted, context-specific approaches that reflect local crops, conditions and farming practices.

About the Data: A Clearer Map for Climate-Smart Agriculture

To map global cropland emissions, a consortium of leading research institutions led by Cornell University along with Colorado State University, University of Minnesota, Food and Agriculture Organization (FAO), International Food Policy Research Institute (IFPRI) and others combined a wide range of ground-based and modeled data sources to harmonize crop and livestock production systems.

Croplands are defined according to FAO as land used to grow temporary (crops with a growing cycle of less than one year that need to be replanted after harvest) and permanent (long-lived) crops and exclude temporary grazing lands and fallow lands (previously cropped fields left unseeded for one or more seasons to let the soil recover).

To map which crops are grown where, how much is harvested and how many calories are produced, the team used the Spatial Production Allocation Model. Then, they layered in spatially detailed information about how crops are typically managed, drawing from FAO, national reports and scientific literature.

Peatland extent was defined using a hybrid map adjusted to align with cropland totals on drained peatlands as reported in the Global Peatland Assessment. Then, emissions were mapped using methods from IPCC’s 2019 Guidelines for National Greenhouse Gas Inventories.

Note that maps of crop emissions do not account for changes in agricultural soil carbon beyond carbon dioxide emissions from crops growing on drained peatlands. The maps also exclude carbon dioxide temporarily stored and released from the crops themselves.

The 4 Crops Driving 67% of Emissions

The biggest opportunity for cutting emissions lies in focusing on how rice, maize, wheat and oil palm are grown. These crops are essential to feed and nourish the world, yet it will be just as essential to rethink how these crops are grown to cut climate pollution and ensure farmers can still earn a living.

Rice accounts for 43% of all cropland emissions globally. This is due primarily to methane emissions from flooded rice fields, a process central to traditional rice farming in much of Asia.

Maize and wheat, though less emissions-intensive than rice per hectare, cover vast areas of the globe and rely heavily on nitrogen fertilizers to grow quickly and sustain high yields, leading to high total nitrous oxide emissions.

Oil palm, though planted on just 2% of cropland, packs a huge climate punch because it’s often grown on carbon-rich peatlands in Southeast Asia.

6 Countries Account for 61% of all Crop Emissions

The six highest-emitting countries — China, Indonesia, India, United States, Thailand and Brazil — together account for 61% of global crop emissions. China, Indonesia, India and Thailand are also among the world’s leading rice producers — a key food staple for billions of people every day — which largely explains their high emissions profiles.

Emissions in other top-emitting countries like Brazil and the U.S. are driven more by fertilizer use than growing rice. Indonesia stands out for its high emissions from planting crops on drained peatlands

Where different crops are grown around the world today often reflect more than just climate or soil conditions — it’s also the result of deep-rooted historical legacies. Colonial trade routes, government subsidies, dietary preferences and infrastructure investments have all shaped agricultural landscapes over time. For example, oil palm dominates parts of Southeast Asia not only because it grows well there, but also due to decades of government incentives, processing infrastructure and export demand. Likewise, wheat and maize that grow in temperate countries reflects public and private investment in breeding higher-yielding seeds, expanding rural extension programs and building commodity markets and trade networks. These patterns persist, even when more climate-smart or resource-efficient alternatives may be available. Understanding these legacies is key to recognizing both the constraints and opportunities for shifting to lower emission, more sustainable cropping systems.

Smoke from burning crop residues in agricultural farmland lifts into the air.
The practice of burning crop residues after harvest releases harmful climate emissions including carbon dioxide, methane and nitrous oxide into the air. Instead, farmers could consider composting the residues or using it for animal feed or bedding. Photo by Toa55/Shutterstock.

Connecting Crop Yields to Climate Impacts

The new maps from Cornell University, in partnership with Land & Carbon Lab, highlight not only where overall emissions are highest (emissions per hectare, or emission areal intensity), but also the climate cost of the energy those crops provide (emissions per calorie, or emission caloric intensity). Here, calories refer to the energy contained in harvested crops, a standard way to compare very different crops on equal footing, whether they’re used for food, animal feed, biofuels or other products. Together, these metrics help us understand not just how much we are emitting, but also how many emissions arise per unit of energy contained in those crops. It’s a bit like looking at how much pollution your car produces overall and how much it emits for every mile you drive. Just as understanding fuel efficiency helps set smarter standards for cars and trucks, this level of detail helps design smarter, more targeted climate solutions for agriculture.   

High emissions don’t always mean a system is inefficient. Some of the most productive farming regions in the world also have the highest emissions. Asia, for example, has the highest emissions per hectare of cropland, but also produces a large share of the world’s calories. Regions like Sub-Saharan Africa have much lower emissions per hectare, mainly because farmers use fewer fertilizers and other inputs and get lower yields. Each hectare emits less, but it also produces fewer calories. As a result, emissions per hectare look small, yet emissions per calorie aren’t proportionally low, since more land is needed to produce the same amount of food. The same pattern shows up when evaluating individual crops: Rice produces nearly half of all crop emissions globally but also delivers 28% of Asia’s calories. Oil palm, another top emitter, is also one of the most land-efficient crops in terms of calorie production.

This points to a core challenge in climate-smart agriculture: High emitting regions are often critical to food security. That doesn’t mean high emissions are justified, but it does mean that simply targeting the biggest emitters and setting blanket emission reduction targets could backfire. Instead, efforts should focus on reducing emissions per unit of crop calorie produced, getting the same (or more) output from each hectare while generating fewer emissions.

Emissions Are Increasing in Key Crop-Producing Regions

Emissions from crop production are not static — they are shaped by decades of decisions about where and how we grow food for human consumption, feed for livestock, fiber for industrial materials and biofuel for energy. Understanding these patterns is essential for designing effective, region-specific strategies to mitigate emissions.

Between 2000 and 2020, crop production increased 50% globally, corresponding to a 17% increase in emissions from croplands across major agricultural zones, especially in parts of Asia and South America. These changes reflect a combination of factors, including rising demand as well as shifts in how and where crops are cultivated — such as expanding crops into new areas, more intensive use of fertilizer and changing crop choices over time.

Nitrous oxide emissions from fertilizer and manure application together increased by 35%, with prominent increases in southern China, India, Indonesia and southern Brazil driven by intensified fertilizer use, increasing cropping intensity and the expansion of fertilizer-dependent crops into new areas.

Methane emissions from rice paddies remained relatively stable overall, but with regional shifts of declining emissions in some areas offset by increasing emissions in others, particularly in South and Southeast Asia. Emissions from crops planted on drained peatlands increased slightly in Southeast Asia, reflecting continued expansion of drainage infrastructure for cultivation of crops like oil palm. However, trends in other regions remain uncertain due to large differences in peatland and drained peatland estimates across datasets.

How to Feed a Growing Population While Reducing Emissions

The issue boils down to one key question: How do we feed a projected 10 billion people by 2050 without driving up emissions?

Using Research for Climate-Smart Food Systems

A full accounting of a company’s contribution to global land pressure includes metrics such as land use change emissions and land occupation (i.e., the amount of the land required to produce a crop). By combining Land & Carbon Lab’s spatially explicit data on land use change emissions and land occupation with these new maps of crop management emissions — with spatially detailed livestock emissions maps coming later in 2026 — policymakers, producers and supply chain actors gain a far more complete and detailed picture of agriculture’s climate footprint. This integrated view enables more targeted, effective interventions to build a climate-smart, resource-efficient global food system that would simultaneously reduce GHG emissions and the pressure on the land itself.

This shouldn’t be a trade-off with climate action. The challenge is navigating the land squeeze, where food production, industrial resources, biodiversity and carbon storage all compete for the same amount of land. The broad solution is to protect natural ecosystems, produce more food on existing agricultural land, reduce emissions and restore degraded land.

Simply swapping out high-emitting crops like rice isn’t the answer. Staple crops are deeply rooted in cultural, culinary, and agricultural traditions that can’t and shouldn’t be easily replaced; longstanding rice farming systems have sustained food security and livelihoods for centuries. Instead, the solution lies in how we grow crops.

Major sources of emissions from lands used to grow crops each need tailored strategies that farmers can implement, in some cases supported by incentives or pressures from governments and companies:

  • For rice, climate impacts can be slashed through smarter water and residue management, like switching from constant flooding to alternate wetting and drying. Instead of burning or tilling leftover rice stalks, they can be used as animal bedding or feed or be composted after harvest. These methods can cut methane emissions nearly in half. However, adoption challenges may persist, like demand for human labor needed to weed intermittently flooded paddies and manually remove straw where mechanization is limited.
  • Fertilizer-related emissions can be lowered using the “4R” approach, which refers to applying the right fertilizer source, at the right rate, at the right time, and in the right place. This means matching fertilizer type to crop needs (e.g., slow-release vs. fast-acting), avoiding over-application, timing application to when crops can actually absorb nutrients — typically during early to mid-growth stages when plants are rapidly growing — and placing fertilizer close to roots instead of broadcasting it across the field to improve uptake. These practices reduce the amount of excess nitrogen left in the soil, which microbes would otherwise convert into nitrous oxide emissions. Field trials show that good 4R management can cut nitrous oxide emissions by 20% to 50%.
  • For crops cultivated on peatlands, raising the water table even partway can significantly cut carbon dioxide emissions. Rewetting peatlands — even partially — keeps more carbon in the ground by slowing decomposition without necessarily halting crop production.

The future of agriculture will depend on how quickly we align past agricultural land use legacies with today’s planetary constraints.