Agriculture is a favorite target among those looking for somewhere to place blame for greenhouse gas emissions. However, recent research from the Environmental Protection Agency (EPA) shows that agriculture has made more progress in cutting emissions than any other industry in the US. According to the report, “Inventory of US Greenhouse Gas Emissions and Sinks: 1990-2022”, US greenhouse gas emissions increased from 2021 to 2022 by +1.3% but agricultural emissions dropped -1.8%.
EPA’s report shows emissions from agriculture totaled 634 million metric tons in CO2 (Carbon Dioxide) equivalents, or 9.99% of all U.S. emissions, during 2022. This represents a decrease of 12 million metric tons, or -1.8%, from 2021, while marking the lowest US agricultural greenhouse gas emissions since 2012. That also puts agriculture’s contributions to total US emissions behind transportation (28%), electric power (25%) and the industrial sector (23%), though slightly ahead of the commercial sector (7%) and the residential sector (6%).
US agricultural greenhouse gas emissions include sources such as livestock enteric fermentation and manure management, N2O (Nitrous Oxide) emitted from managed agricultural soils from fertilizers and other management practices, and fossil fuel combustion from agricultural equipment. Indirect emissions from electricity in the agricultural sector are about 5% of sector emissions.
In 2022, agricultural soil management was the largest source of N2O emissions. Nitrous oxide (N2O) is produced by biological processes that occur in soil and water and by a variety of anthropogenic activities in the agricultural, energy, industrial, and waste management fields. While total N2O emissions are much lower than CO2 emissions, N2O is 265 times more powerful than CO2 at trapping heat in the atmosphere over a 100-year time frame. And while agricultural soil management represents approximately 50% of all agricultural emissions, it’s only 4.6% of total U.S. emissions.
Overall, N2O emissions in the United States in 2022 accounted for 398.8 MMT, representing a decrease of -3.4% since 1990 and a decrease of -2.5% since 2021. N2O emissions from agricultural soil management increased by +0.7 % from 1990 to 2022. However, that compares to a more than +10% increase in from “stationary combustion”, the second largest source of N2O emissions in 2022, and a nearly +50% increase in the wastewater management sector, the third largest source of N2O emissions.
Enteric fermentation was the largest source of CH4 (Methane) emissions in the United States in 2022. From 1990 to 2022, emissions from enteric fermentation have increased by +5.2%, according to EPA. However, from 2021 to 2022, emissions decreased by -2%, largely driven by a decrease in beef cattle populations.
Overall, livestock-related emissions from enteric fermentation and manure management contributed 192 million metric tons and 82 million metric tons, respectively, to total US emissions. These two emission sources represented 46% of agricultural emissions, but only 4.3% of total U.S. emissions.
Other agricultural emission sources include methane from rice cultivation at 19 million metric tons, CO2 from urea fertilization at 5.3 million metric tons, CO2 from liming at 3.3 million metric tons, and CO2 from field burning at 0.8 million metric tons. Combined, these remaining categories represented less than 5% of agricultural emissions and 0.4% of U.S. emissions.
AFBF economist Daniel Munch notes that a comparison of 2022 emissions to 1990 emissions shows U.S. agricultural emissions have increased by 6.4%. However, that’s not the full story. Productivity is increasing, and emissions are on the decline relative to this productivity and population increase. Compared to 1948, farmers and ranchers are producing nearly three times more in output per unit of input they use. Even more impressive, productivity – and production – is rising while agricultural land used is declining. Acreage in operation has declined by -323 million acres since 1950, almost double the size of Texas. This means that farmers and ranchers continue to produce more using fewer resources and the additional decrease in agricultural emissions shows that voluntary, market-based incentives are helping farmers and ranchers accomplish this.
For example, Munch says between 1990 and 2022, U.S. dairy farmers have increased milk output by +53%, going from 148 billion pounds to 226 billion pounds to meet increasing global demand for products like cheese, butter, and dairy powders. During this same timeframe, emissions from enteric fermentation from dairy cattle per billion pounds of milk produced have dropped -26%, going from 293 million metric tons to 216 million metric tons per billion pounds of milk produced. It’s a similar story for red meat. In 1990, U.S. farmers produced 39 billion pounds of red meat; this grew 44% to 55.6 billion pounds in 2022. In the same timeframe, greenhouse gas emissions from enteric fermentation from beef cattle dropped -28%. Munch says that, accounting for productivity gains, the +6.4% increase in agricultural emissions drops to a -25% decline since 1990. Read the full analysis HERE.
“The latest numbers demonstrate farmers’ and ranchers’ commitment to growing the food and fiber America’s families rely on while improving the land, air, and water, a benefit to the farm and the climate,” said American Farm Bureau Federation President Zippy Duvall in a press release. “The latest numbers should also serve as inspiration to lawmakers who can build on this progress by passing a farm bill, which not only provides a safety net for farmers, but also helps them meet sustainability goals.” (Sources: EPA, AFBF)
