Disclosing the future food security risk of China based on crop production and water scarcity under diverse socioeconomic and climate scenarios

Climate change and human development may lead to a serious crisis in food security in China, especially in areas with both water shortages and large grain production. Thus, the quantitative evaluation of future food security risk considering water scarcity is increasingly important. Here, we combined water scarcity and crop production data under different scenarios of representative concentration pathways (RCPs) and shared socioeconomic pathways (SSPs), incorporating demographic, food habit and water resource factors, to develop a new framework for measuring China's food security risk. The results show that the water scarcity and crop production-water crisis (CPWC) of China would both be aggravated during the 21st century. In particular, northern China might face more serious water scarcity than southern China and has a higher contribution rate to the national crop production-water crisis. Food scarcity in China might occur at some point in the 21st century under all SSP scenarios, except SSP1 (sustainability development pathway). The next 40 years could be the most critical period for ensuring China's food security. Moreover, by comparing the RCP2.6 and RCP6.0 scenarios, we also find that higher food production does not represent lower food security risk. The food security risk of the RCP26 scenario with higher food production was significantly higher than that of the RCP6.0 scenario at the same SSP because higher grain production comes from water shortage areas. From the perspective of societal development scenarios, SSP1 provided better results for both the risk of food security and water security in the 21st century. Our findings therefore provide useful information for a comprehensive understanding of long-term food security and water security of China.