Study: U.S. farm irrigation avoids 363 times more greenhouse gas emissions than it creates

A Colorado State University study in PNAS found that irrigated agriculture in the United States prevents far more greenhouse gas emissions than it causes. By keeping crop production on existing land, irrigation avoids the need to convert natural ecosystems to farmland, and the avoided land-use emissions are roughly 363 times larger than the direct emissions from irrigation. Direct emissions mainly come from energy used to pump water, both on farms and for interbasin transfers. The researchers estimate that replacing fossil fuel pumps with electric pumps and decarbonizing the grid would cut those emissions further. The total avoided emissions equal 6.86 gigatons, more than the entire U.S. emissions total in 2024. The study is the first to compare direct and indirect emissions from U.S. irrigation. It argues that climate-smart agriculture policy should count both field-level emissions and the land-use effects of crop production. The authors note that nitrogen application and livestock methane were outside the scope.