Spring Frost Intensity and Crop Yield Loss: A Global Analysis under Climate Change

Spring frost is an extreme weather event that can significantly affect food security. However, the intensity of spring frosts and their impacts on crops on a large scale are not well documented in the context of global warming. 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 defined intensity factor indices, including temperature difference, temperature fluctuation, and the 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 found that the intensity factor indices increased with temperature anomaly, and these intensity factors were positively correlated with crop yield loss. Furthermore, multiple linear regression and principal component analysis suggested that temperature anomaly not only caused the intensity of spring frost to increase but also, together with intensity factors (temperature fluctuation and the duration of spring frost events), exacerbated yield loss, while temperature difference decreased yield loss.

These findings are important for evaluating the impacts of climate change on food security.