Rice yield benefits from historical climate warming to be negated by extreme heat in Northeast China

Abstract Rice is currently benefiting from climate warming in Northeast China, but whether such positive effects will continue in the future remains unknown. Using county-level rice yield and climate data in Northeast China from 1980-2015, we examined the impacts of individual and combined climate variables on rice yields, estimated climate-induced yield changes, and quantified the associated contributions of these climate variables. The results suggest that climate change has caused a 10.1% yield increase in Northeast China since 1980. The main reasons are the reduced chilling damage (+5.4%) and warming below the optimum growth temperature (+4.6%). The influence of warming beyond the optimum growth temperature (i.e., high-temperature extremes) is quite limited (-0.054%) at present. However, with continuous warming, the harmful impact of such high-temperature extremes will outweigh other positive climate effects when the temperature increases by 3.36°C. Therefore, high-temperature extremes cannot be ignored despite their influence on rice yield being quite limited in Northeast China. Climate change mitigation and heat tolerance breeding are thus necessary for rice production in Northeast China.