Greenhouse gas emissions from US irrigation pumping and implications for climate-smart irrigation policy

Avery W Driscoll; Richard T Conant; Landon T Marston; Eunkyoung Choi; Nathaniel D Mueller

doi:10.1038/s41467-024-44920-0

Greenhouse gas emissions from US irrigation pumping and implications for climate-smart irrigation policy

Nat Commun. 2024 Jan 23;15(1):675. doi: 10.1038/s41467-024-44920-0.

Authors

Avery W Driscoll¹, Richard T Conant², Landon T Marston³, Eunkyoung Choi², Nathaniel D Mueller^{4

2}

Affiliations

¹ Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA. averywdriscoll@gmail.com.
² Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, USA.
³ Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
⁴ Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA.

Abstract

Irrigation reduces crop vulnerability to drought and heat stress and thus is a promising climate change adaptation strategy. However, irrigation also produces greenhouse gas emissions through pump energy use. To assess potential conflicts between adaptive irrigation expansion and agricultural emissions mitigation efforts, we calculated county-level emissions from irrigation energy use in the US using fuel expenditures, prices, and emissions factors. Irrigation pump energy use produced 12.6 million metric tonnes CO₂e in the US in 2018 (90% CI: 10.4, 15.0), predominantly attributable to groundwater pumping. Groundwater reliance, irrigated area extent, water demand, fuel choice, and electrical grid emissions intensity drove spatial heterogeneity in emissions. Due to heavy reliance on electrical pumps, projected reductions in electrical grid emissions intensity are estimated to reduce pumping emissions by 46% by 2050, with further reductions possible through pump electrification. Quantification of irrigation-related emissions will enable targeted emissions reduction efforts and climate-smart irrigation expansion.