In many ways, 2022 was a bad year for U.S. agricultural trade. Russia’s invasion of Ukraine cut off exports of wheat, sunflower, and other products from both countries. Mexico proposed banning imports of GMO corn from the United States. And the Office of the U.S. Trade Representative and the U.S. Department of Agriculture (USDA) were both left trying to operate without anyone in charge of agricultural trade until late December when the Senate finally confirmed two highly qualified nominees. Although total agricultural exports did rise in 2022 to record levels, so did imports, which nearly exceeded exports. USDA projects that imports will fully overtake exports in 2023, which has only happened twice before in the past 50 years. These trends shape the costs of farm inputs and outputs, including food, fiber, livestock feed, and biofuels, and affect where and how agricultural production occurs. That, in turn, not only affects farmers’ bottom line and consumers’ pocketbooks, but the climate as well.
Every country and region produces agricultural goods with a different carbon footprint—that is, the quantity of greenhouse gas emissions generated per pound, bushel, or other unit of agricultural production. This is due to factors like fertilizer use, irrigation, and other farming practices; domestic policy support for agricultural innovation and production; and environmental conditions such as climate and soil quality. If trade policies shift production from a country with a high carbon footprint to one where production is more efficient, total global emissions could decrease, and vice versa. In fact, concentrating global crop production in optimal locations with high yields could decrease its carbon and biodiversity footprint by 71% and 87%, respectively.
Yet trade has not been a major focus of U.S. policy debates about how to decarbonize agriculture or otherwise improve environmental sustainability. Policy proposals have generally focused on other areas such as how to increase domestic adoption of no-till farming and other practices, limit agriculture’s land use footprint, and sustainably manage livestock operations. Only recently has Congress considered agricultural trade’s potential role in decarbonization. The 2021 FOREST Act, for instance, would limit U.S. imports of beef, soy, and other commodities originating from illegally deforested land. We show that agricultural trade and trade policy can play an even larger potential role in cutting agricultural global carbon footprint.
By analyzing data from the Food and Agriculture Organization of the United Nations (FAO) on five of the world’s top agricultural exports—maize (corn), wheat, beef, pork, and chicken—we find that the United States produces several key commodities with a lower carbon footprint than other major exporters (defined as the countries that accounted for 80% of global export quantity for each product from 2015-2019). However, many countries with higher carbon footprints export more than countries with lower emissions. In many cases, exports are also growing most quickly in high-emissions countries. For example, while the United States produces beef and chicken with a smaller carbon footprint than Brazil, exports are growing at a much faster rate in Brazil than in the United States.
These findings suggest that policy makers should consider policies that concentrate production in countries with the lowest rates of agriculturally-driven deforestation and other land-use change, which is a large contributor to agriculture’s carbon footprint. In the United States, for example, Congress could pass policies, such as the FOREST Act, that require imports to be deforestation-free or to meet other minimum standards. The executive branch can act too, for instance by developing trade agreements that increase exports of goods the United States produces with a relatively low footprint.
What goods does the United States produce with the lowest relative carbon footprint?
For most agricultural goods examined, the carbon footprint per unit of production in the United States is below the average of other top exporting countries (Figure 1). For example, maize (corn) production in other top exporting countries is, on average, more than two and half times more emissions-intensive than in the United States. Although the other countries do better when it comes to emissions from input use (synthetic nitrogen fertilizer, organic fertilizer, fuel use, and crop protection), they generate eight and a half times more emissions from land-use change. This is in part because yields in the other countries are lower than in the United States—about 1/3 lower—meaning that more land must be converted from forest, grassland, and other native vegetation to farmland. It is also partially due to less strict land use restrictions in some other countries, including Brazil, and to the high carbon content of forestland converted to maize in some other countries, such as in Argentina.
For beef and chicken production, emissions from production and land use per kilogram (kg) of meat produced are substantially lower in the United States than in the other top exporting countries. On average, the carbon footprint of beef or chicken in other top exporting countries is more than two and three times higher, respectively. One key reason, as with maize production, is that production in the United States is generally more efficient than in other countries, raising animals to slaughter weight quickly so that less feed and thus less pasture, cropland, and land conversion is required to produce each kg of meat. The picture is different, however, for pork production. The United States, despite negligible land-use change emissions, produces pork with slightly (4.5%) higher emissions than the other top exporting countries (Figure 1).
International competitiveness and carbon footprints are not aligned
Although the United States has a relatively low carbon footprint for many agricultural exports, other countries with higher emissions often export more. If production and exports of agricultural products were concentrated in the countries with the smallest carbon footprints, total global emissions could be minimized. But export quantities and emissions intensities are not always aligned.
When it comes to the production of beef, chicken, and pork, the largest exporters from 2015-2019—Brazil (beef), Brazil (chicken), and the United States (pork)—don’t have the lowest carbon footprints (Figure 2). In fact, of the top exporting countries, Brazil’s beef production has the second highest emissions intensity when emissions from deforestation and other types of land-use change are accounted for. The emissions intensity of beef production in Brazil is over 50% higher than in Australia and almost two and half times greater than in the United States, the second and third largest exporters, respectively.
Brazil is also the largest exporter of chicken, despite having an emissions intensity that is almost 80% higher than chicken production in the United States, the second largest exporter. Ignoring land-use change emissions, chicken production in Brazil is relatively efficient and low-emitting. However, emissions from land-use change involved in producing soy and other feed for chicken far exceed those in the United States.
Of the top seven pork-exporting countries, which account for over 80% of global pork exports, the United States is the largest exporter and the fourth most emissions-intensive producer. For every kilogram of pork protein produced, the United States emits nearly 30% (or 12 kilograms carbon dioxide-equivalent) more than Germany, the second largest exporter, and over 82% (~23 kilograms carbon dioxide-equivalent) more than Canada, the third largest exporting country. This is partially due to high levels of methane emissions from the lagoons and pits predominantly used to store manure in the United States, as well as differences across countries in the crops used for feed.
Russia and the United States are the top two exporters of wheat but also have the highest rates of emissions from production among major exporters and some of the highest when including land-use change (Figure 2). Synthetic fertilizer use is largely responsible for the United States’ high carbon footprint; it is the source of over a third of U.S. wheat emissions, but only accounts for about 10% of Russia’s.
The picture is less clear for maize since just five countries—the United States, Brazil, Argentina, Ukraine, and France—made up over 80% of global exports from 2015–2019, but emissions data from FAO-LEAP is unavailable for Brazil and land-use change data is unavailable for France. Nevertheless, the United States, which is the world’s top maize exporter, has a substantially lower carbon footprint than Argentina and Ukraine (Figure 2). Despite having the most emissions from inputs, particularly synthetic fertilizers, emissions from land-use change are relatively low in the United States. This is partially due to the high yields that fertilizers and other inputs and factors enable; U.S. maize yields in 2021 were more than twice as high as Brazil’s and about 50% higher than Argentina’s.
However, land-use change emissions for corn and other products in the United States are also generally low because the primary methods used by FAO and others to calculate emissions from land use change only consider recent land use-change. For instance, while Argentina has cleared land for corn and other crops recently, most U.S. farmland was cleared decades ago if not longer. Further research into the carbon footprint of agriculture and trade’s potential to reduce it must address this methodological shortcoming, for instance by estimating the marginal impact of new agricultural production.
The average emissions intensity of global agricultural trade is on track to increase
Unfortunately, export data from 2000 to 2019 reveals that, for many agricultural products, exports from countries with high emissions intensities are increasing more quickly than exports from countries with low emissions intensities (Figure 3). For example, compared to the United States, exports from Brazil have increased almost three times as quickly for beef, nearly three times as fast for chicken, and more than 22 times more quickly for maize. Likewise, growth in pork exports from the United States have outpaced exports from Germany and Canada.
To be clear, exports aren’t becoming more emission-intensive for all products. U.S. wheat exports fell from 2000 to 2019, while exports grew relatively quickly in countries with lower emissions intensities such as Russia, Canada, France, and Ukraine. Although Russia’s invasion of Ukraine dramatically affected agricultural production and trade, its 2022 wheat exports were estimated to be near record-high levels while U.S. exports have continued their long-term downward trend.
Nevertheless, the growth in exports from countries with relatively high carbon footprints could lead to a global rise in emissions. If this growth continues, the average carbon footprint of maize, pork, and beef exports in 2040 would be 18%, 3%, and 10% higher, respectively, than if current export patterns remained constant (Table 1). The average emissions per unit of wheat and chicken, on the other hand, would decrease by around 11% and 7%. Total emissions embodied in these exports would lead to an increase in emissions of about 63 million tonnes CO2-equivalent. This is greater than all agricultural emissions from major farm states like Texas, Iowa or California.
Next steps: Policy and research to reduce the emissions from agricultural exports
Ultimately, location matters. Concentrating production and export of agricultural goods in countries with relatively low emissions intensities could reduce global agricultural emissions. But currently, the largest exporters are rarely the most climate-efficient exporters. And recent export trends don’t provide much reason for hope that international trade will correct course without several types of interventions.
First, trade officials, advocates, and other experts should raise awareness about the climate mitigation potential that lies in agricultural trade policy.
Second, researchers should examine several questions about the environmental impacts of agricultural trade that are key to informing policy. These include:
What are the impacts of increasing export of relatively low-carbon products on importing countries’ food systems? Increasing exports can affect the course of agricultural development in importing countries in a variety of ways including by undercutting domestic production.
What is the marginal climate impact of increasing exports? Our analysis relies on the estimates of the average carbon footprint of production in different countries. However, it is possible that in any given country, the next unit of production would be substantially more or less emissions-intensive than the average e.g. if new production involves deforestation or other land-use change.
How can subnational differences in emissions be leveraged? For instance, if one region of a country produces beef with a lower footprint than other regions, are there ways to concentrate future export growth in that region?
What are the non-climate tradeoffs of increasing exports? While reducing GHG emissions is critical, other types of environmental impacts such as nutrient pollution and resource use such as water use must be considered too.
Third, policy makers should consider different trade policies to shift agricultural production and exports from high emissions to low emissions countries. One option is to incorporate agricultural products into a renewed WTO Environmental Goods Agreement that aims to reduce tariffs for environmentally beneficial products. Countries should also examine how reducing trade barriers through bilateral or multilateral agreements could lower emissions. For instance, China applies a greater tariff on U.S. beef than on beef from Australia and several other countries with more emissions-intensive beef than the United States. Negotiating reductions on the tariffs on U.S. beef could therefore reduce the carbon footprint of Chinese beef imports. It could, however, also spur increased beef consumption, negating some of the climate benefits. These calculations, therefore, warrant careful study.
Likewise, the United States and other major exports should examine how trade promotion programs can be used to expand international demand for exports that replace higher-carbon products. For example, promotion of U.S. beef could reduce global agricultural products if it displaces other countries’ imports of higher-carbon beef. Providing additional support to companies and industries seeking to export goods produced using climate-smart practices could further enhance the climate benefits. Currently, U.S. Department of Agriculture trade programs, such as the Market Access Program (MAP) and Foreign Market Development Program (FMD), do not take into account the carbon footprint, or other environmental impacts, of products.
Finally, governments should continue aiming to reduce the carbon footprint of production within countries using a wide variety of policy instruments. For example, public investment in agricultural research is critical to developing technologies and practices that cut emissions and boost yields, which is important for reducing land use change. Reducing trade barriers for productivity-enhancing and emissions-reducing technologies can also help producers across the world adopt more climate-friendly practices. Likewise, investments from high-income countries in international research and other agricultural development efforts in lower-income countries can enhance their productivity and environmental footprint.
Ultimately, reducing the agricultural sector’s greenhouse gas emissions is a pressing challenge, and, given the interconnectedness of our food system, it demands global solutions that can account for international trade. To achieve global agricultural emissions reductions, policymakers should consider a wide range of trade policy options and researchers should aim to provide them with the data, analysis, and tools needed to make more informed decisions.
We use FAOSTAT for data on export quantities of “Meat, chicken,” "Meat, pork" and "Meat, cattle, boneless, (beef & veal)", downloaded September 2021. We use FAOLEAP v1.0 for estimates of the carbon footprint of crop production by country. We use estimates of livestock carbon footprints from Kim et al. (2019), which calculated them using FAO GLEAM-i v2.0 revision 3. 2040 projections were calculated by linearly extrapolating export trends from the 2000–2019 trends. Estimates of 2040 emissions rely on the assumption that countries’ emissions intensities remain.