The Emissions Benefits of Irrigation Far Outweigh the Impacts of the Emissions They Produce, According to Study

      Agricultural greenhouse gas (GHG) emissions in the form of land use and land conversion account for nearly a quarter of global GHG emissions. A study published in Proceedings of the National Academy of Sciences (PNAS) notes that agricultural practices “drive both direct, on-farm emissions, and indirect land use change emissions through yield effects.” Specifically, the authors compare the direct emissions of irrigation to the yield increase benefits that irrigation provides in terms of spared land use, which provide indirect emissions reduction benefits.

     The study considers land sparing and avoiding the conversion of forest lands to grasslands and croplands.

“Due to land sparing, US irrigation provides an estimated gross GHG benefit of 6.86 Gt CO2e, while producing 0.019 Gt CO2e of direct emissions annually.”

     That is a huge emissions benefit, about 363 times less emissions with irrigation than would have been emitted without it.

     The researchers, from Colorado State University, simply stress that irrigation allows more crops to be grown on less land, and their study quantifies how much, and it is quite a benefit. According to Phys.org

“We’re able to show this large benefit of U.S. irrigation to greenhouse gas emissions from the food system,” said co-author Nathan Mueller, a CSU associate professor in the departments of Ecosystems Science and Sustainability and Soil and Crop Sciences.”

“Yet, when we talk about water use, particularly in the Western U.S., there are trade-offs with every use and trade-offs beyond food and beyond greenhouse gas emissions. Our work provides one piece of the puzzle to help examine some of the very complicated societal cost-benefit questions surrounding water use.”

     CSU alumnus Alex Brown’s family has been farming and ranching in Colorado’s Yuma County for 120 years on the same land. It is one of the state’s top agricultural producing counties. He notes that farmers in the area take conservation seriously.

“Irrigation is a powerful adaptation strategy,” Driscoll, the study lead, added. “It increases productivity; it increases resilience to heat and drought stress, and of course, maintaining and increasing agricultural production is a critical priority.”

“At the same time, we need to reduce food system emissions, so understanding how these two challenges interest with one another is a priority. This work allows us to grasp some of those trade-offs and synergies a little better.”

 

   

 

References:

 

Greenhouse gas benefits of agricultural irrigation far outweigh emissions costs, study finds. Jayme DeLoss, Colorado State University, edited by Sadie Harley, reviewed by Robert Egan. Phy.org. September 15, 2026. Greenhouse gas benefits of agricultural irrigation far outweigh emissions costs, study finds

Global greenhouse gas cobenefits of US irrigated agriculture. Avery W. Driscoll, Justin A. Johnson, Joey E. Blumberg, Alison E. King, Seth A. Spawn-Lee, and Nathaniel D. Muelle. PNAS. Vol. 123 | No. 39.  Global greenhouse gas cobenefits of US irrigated agriculture | PNAS