Comparison of Winter Wheat Climatically Suitable Regions in China during 2069–2098 under Medium and High Greenhouse Gas Emission Scenarios

By adopting future climate projection data with a resolution of 1° (latitude)× 1° (longitude) driven by regional climate models during the base period from 1981 to 2005 and from 2069 to 2098 under representative concentration pathway (RCP) 4.5 and 8.5 along with temperature, radiation, and precipitation indicators, the spatial distribution characteristics of thermal resources, planting boundary, theoretical growth period, and climatically suitable region of winter wheat in China were analyzed and compared under RCP4.5 and RCP8.5. The main findings of this study are as follows: Compared with the base period, there were significant differences in China’s thermal resources, winter wheat planting conditions, and climatically suitable region under RCP4.5 and RCP8.5. Most importantly, compared with RCP4.5, the thermal resources are projected to increase in most areas in China during 2069–2098 under RCP8.5. The northern and southern boundaries of winter wheat are projected to move northward and eastward; and therefore, the cultivable area would consequently increase. In most areas, the theoretically suitable sowing date would be delayed, theoretical maturity date would shift to an earlier date and, as a result, the potential growing season would be shortened. Meanwhile, allocation of radiation−temperature−precipitation in the potential growing season improved the climate suitability of winter wheat. However, because winter wheat is a chimonophilous crop that is sensitive to high-temperature stress, the negative effects under RCP8.5, such as extremely hot weather and asymmetric warming, are likely to offset the favorable effects of the allocation of radiation−temperature−precipitation mentioned above; thus probably reducing the planting suitability of winter wheat. Therefore, future research should be devoted to mitigating climate change in order to ensure the security of China’s food production.