How global warming alters future maize yield and water use efficiency in China

Abstract

Agricultural production is highly sensitive to climate change. Scientifically evaluating the impact of climate change on agriculture lays a foundation for stakeholders to make evidence-based decisions. However, the potential changes to China's maize production and water use efficiency (WUE) under the 1.5 °C and 2.0 °C global warming (GW1.5 and GW2.0) scenarios still remain unclear. In this study, the spatiotemporal changes in China's maize yield and WUE relative to the reference period (1986–2005) under GW1.5 and GW2.0 were simulated using the calibrated and validated CERES-Maize model. The climate of GW1.5 could be beneficial for maize yield and WUE, but these benefits declined when warming reached 2.0 °C above the pre-industrial level. Under GW2.0, China's main food-producing regions became high-risk areas for maize yield reductions. The decrease of maize yield in the north spring maize zone and Huanghuai Plain spring–summer maize zone were both higher than that in other planting zones. Increasing risk of yield reduction and a looming water use crisis are likely to bring unprecedented challenges to sustainable agricultural development. Controlling the temperature rise within 1.5 °C would reduce the yield reduction risk in each planting zone by 11.01–75.69%, which is conducive to ensuring China's food security.