Impact of Spring Frost Intensity on Global Crop Yield Under Climate Change

Spring frost is an extreme weather event that can severely impact food security. However, the extent of its effects on crops on a large scale, particularly in the context of global warming, is not well-documented. In this study, we analyzed temperature data, global production data of three major crops (corn, soybeans, and winter wheat) from 1981 to 2016, and global temperature anomaly data to investigate the impacts of spring frost on crop yield. We also developed intensity factor indices, including temperature difference, temperature fluctuation, and duration of spring frost events, to measure the intensity of spring frost events. Our results showed that the number of spring frost events decreased due to global warming, but the yield loss of crops impacted by spring frosts increased from 1981-2001 to 1986-2016. Specifically, corn's yield loss increased by 5.63 percentage points, soybean's yield loss rose from 12.32% to 15.01%, and winter wheat's yield loss increased from 16.42% to 18.99%. We also observed that the intensity factor indices increased with temperature anomaly and were positively correlated with crop yield loss. Furthermore, our multiple linear regression and principal component analysis suggested that temperature anomaly not only increased the intensity of spring frost but also, together with intensity factors, exacerbated the yield loss, while temperature difference reduced the yield loss. These findings are crucial for evaluating the impacts of climate change on food security.