The Impacts of Warming Temperatures on US Sorghum Yields and the Potential for Adaptation

Abstract

Growing evidence suggests that climate change will have significant negative effects on agricultural productivity across many highly concentrated production regions. Much empirical analysis has begun to focus on both short‐ and long‐run adaptation within these regions. US sorghum production has received relatively less attention than other commonly grown grains, such as corn and wheat, despite that it is one of the top five grains grown in the US and ranks in the top ten of all crops grown globally. We match farm‐level yield outcomes with fine‐scale gridded weather data to generate a panel of Kansas sorghum producers totaling 45,971 observations spread across 7,298 farms and thirty‐eight years. Fixed effects regressions leverage substantial cross‐sectional and temporal variation in yields and weather to estimate the effect of warming temperatures on yields. Results suggest that sorghum is quite sensitive to warming temperatures—as moderate increases of 2°C in growing season temperatures lead to an average 24% reduction in yields—thereby raising doubts about its potential for offsetting climate change impacts relative to other crops. We also consider whether warming impacts can be lessened through growing season adjustments and find very little support for this form of adaptation. A cross‐sectional identification approach that encapsulates additional forms of adaptation also finds limited adaptation potential for sorghum producers. As a possible upside, we find evidence that sorghum's ability to withstand extreme heat has decreased by 70% over time, suggesting that there might exist currently outdated production practices and/or seed varieties that could help offset warming impacts.