Future extreme temperature and its impact on rice yield in China

Rice in China is increasingly suffered from extreme temperature stress (ETS) with ongoing climate change. It is projected that ETS would increase notably across the world in the future. However, the spatio-temporal change of ETS in main rice planting areas in China is still unclear; and the future yield loss caused by ETS (YLETS) has seldom been investigated quantitatively. In this study, we first investigated the spatio-temporal change of ETS across China under 20 climate change scenarios consisting of five global climate models and four Representative Carbon Pathways (2.6, 4.5, 6.0, and 8.5). Then, using a process-based crop model (MCWLA-Rice), its 30 sets of model parameters and the 20 climate change scenarios, we conducted a super-ensemble assessment to investigate the YLETS over 2020-2049, relative to the baseline period (1980-2009), across China. The results showed that, an increased heat ETS and a decreased cold ETS would be expected for most areas. As a result, a large spatial variability of yield loss would be expected in the future, including severely cold stress for region I (northeastern China, single rice) and region IV (southern China, early rice), but severely heat stress for region III (the middle and lower reaches of Yangtze River, single rice) and region IV (southern China, late rice). Comparing yield loss from both ETS, a decreased change in yield loss would be mainly expected in region I (northeastern China, single rice), while an increased change for region III (the middle and lower reaches of Yangtze River, single rice) and IV (southern China, late rice), with less change for region II (southwestern China, single rice) and IV (southern China, early rice). Finally, some adaptation measures were proposed for the ETS-sensitive areas. Our findings are useful to develop effective policies to cope with climate risk and relieve ETS disasters.