A climate change modeling paper published in the latest issue of Nature, an internationally renowned academic journal, found that most staple crops may suffer severe yield losses due to climate change, even if mitigation measures to limit the impact of climate change are taken into account. The study evaluated six staple crops, corn, soybeans, rice, wheat, cassava and sorghum, and found that only rice might be able to avoid severe losses.
The paper introduced that climate change is expected to affect the global food system, but people are still uncertain about the extent of its impact and how adaptation measures such as changing agricultural methods will mitigate these impacts. Previous studies have focused on results in specific regions such as the United States, but have reached conflicting conclusions on the impact of adaptation measures. Some modeling shows that adaptation measures may affect global agricultural productivity. However, few studies have focused on the adaptation of real-world producers at the global level.
In this study, Andrew Hultgren, co-corresponding author of the paper, University of Illinois at Urbana-Champaign, and Solomon Hsiang of Stanford University, together with collaborators, compiled a dataset of six staple crops, including corn, soybeans, rice, wheat, cassava and sorghum, based on data from 12,658 regions in 54 countries to estimate the impact of producer adaptation measures in the 21st century.
The authors of the paper estimate that for every 1°C increase in temperature above pre-industrial levels, the daily output per person will decrease by 120 calories, equivalent to 4.4% of the current daily consumption. They believe that under a high-emission scenario, corn production in the United States, eastern China, central Asia, southern Africa, and the Middle East may decrease by up to 40% by the end of the 21st century, wheat losses in Europe, Africa, and South America will be 15%-25%, and wheat losses in China, Russia, the United States, and Canada will be 30%-40%. They also noted that income growth and the implementation of adaptation strategies could reduce global losses by 23% by 2050 and 34% by 2100 compared to a scenario without adaptation measures.
The authors said the study found that the decline of today's breadbasket regions with suitable climates but limited adaptive capacity would drive global impacts, with significant losses in low-income regions. They concluded that further adaptation measures and consideration of cropland expansion may be needed in the future to ensure food security and mitigate climate impacts.
