Climate change has increased crop water consumption in Central Asia despite less water-intensive cropping

Abstract

Climate change and land use change are crucial determinants of crop water consumption, particularly in drylands where water scarcity limits crop production. In Central Asia, the effects of land use and climate changes on crop water consumption remain unknown. We estimated the dynamics of crop water consumption by mapping annual actual evapotranspiration from Landsat imagery from 1987 to 2019 for all irrigated croplands in the Amu Darya Basin, the largest transboundary river in Central Asia. Total crop water consumption increased by 10%, while average consumption per unit area increased by 18%. Climate change was the main driver of the rising crop water consumption; land use changes towards less water-intensive cropping practices offset only 3% of this increase. Our findings underscore that crop production will become increasingly challenging amidst accelerating climatic changes and that changing cropping practices alone will be insufficient to curb the growing water scarcity without a global commitment to reducing emissions.