Irrigated agriculture has important implications for achieving the United Nations Sustainable Development Goals. However, there is a lack of systematic and quantitative analyses of its impacts on food–energy–water–CO₂ nexus. Here we studied impacts of irrigated agriculture on food–energy–water–CO₂ nexus across food sending systems (the North China Plain (NCP)), food receiving systems (the rest of China) and spillover systems (Hubei Province, affected by interactions between sending and receiving systems), using life cycle assessment, model scenarios, and the framework of metacoupling (socioeconomic-environmental interactions within and across borders). Results indicated that food supply from the NCP promoted food sustainability in the rest of China, but the NCP consumed over four times more water than its total annual renewable water, with large variations in food–energy–water–CO₂ nexus across counties. Although Hubei Province was seldom directly involved in the food trade, it experienced substantial losses in water and land due to the construction of the South-to-North Water Transfer Project which aims to alleviate water shortages in the NCP. This study suggests the need to understand impacts of agriculture on food–energy–water–CO₂ nexus in other parts of the world to achieve global sustainability.

Groundwater depletion will reduce cropping intensity in India, and canal irrigation cannot fully substitute for this loss.

India relies on groundwater irrigation to produce staple grain crops that provide over half of the calories consumed by its over 1.3 billion people. While groundwater has helped India achieve grain self-sufficiency, aquifers have been overexploited across much of the country and its implications for crop production are unclear. To understand how groundwater depletion affects staple grain (wheat, rice, maize, pearl millet, and sorghum) production in India, we ran district-level panel regressions using agricultural census, groundwater observation, and gridded weather datasets over a ten-year study period (2004–2013). We find that nationally, declining groundwater levels are associated with significant reductions in yield, cropped area, and production for wheat, rice, and maize in the winter season. Despite the negative impacts of groundwater depletion on crop production, we find little evidence that farmers are switching from planting more water-intensive to less water-intensive grains. Using profit-based decision modeling, we further investigated the effects of agricultural energy prices on crop choice in the monsoon season across Haryana and Punjab, which are responsible for over 60% of India’s grain production, have high electricity subsidies, and have rapidly depleting water tables. We find that eliminating energy subsidies for groundwater pumping would likely not encourage farmers to switch to planting less water-intensive crops, though sensitivity analyses suggest that it could encourage the adoption of increased water conservation efforts. In summary, our analyses reveal a discernable impact of groundwater depletion on crop production in India and suggest that reducing or removing energy subsidies may largely affect water use but not crop choice.