Nonlinear temperature effects indicate severe damages to U.S. crop yields under climate change

Area of Science:

• Agricultural Science
• Climate Science
• Economics

Background:

• The US is a major global producer of corn and soybeans, vital for world food supply.
• Understanding crop yield responses to temperature is critical for food security.

Purpose of the Study:

• To analyze the impact of daily temperature distribution on corn, soybean, and cotton yields.
• To quantify the nonlinear and asymmetric relationship between temperature and crop yields.
• To project future yield changes under different climate warming scenarios.

Main Methods:

• Paired county-level crop yield data with a fine-scale daily weather dataset.
• Analyzed time-series and cross-sectional variations in temperature and yield.
• Utilized the Hadley III climate model for future projections.

Main Results:

• Optimal temperatures for yields: 29°C for corn, 30°C for soybeans, 32°C for cotton.
• Temperatures exceeding these thresholds cause significantly steeper yield declines.
• Predicted yield decreases of 30-46% (slow warming) to 63-82% (rapid warming) by century's end.

Conclusions:

• Crop yield response to temperature is nonlinear and asymmetric, suggesting limited historical adaptation.
• Future climate warming poses a substantial threat to US agricultural productivity.
• Urgent adaptation strategies may be needed to mitigate significant yield losses.