This study investigates the impact of warming temperatures on summer carbon sequestration in the U.S. Corn Belt using a decadal time series of hourly CO2 concentration measurements. The analysis reveals that while warming has a positive effect on early crop growth CO2 uptake, it reduces net CO2 uptake during the peak growing season in both croplands and natural ecosystems. Future summer temperature increases are projected to decrease annual CO2 sequestration in the Corn Belt by 10–20%, challenging the assumption that warming consistently benefits CO2 sequestration in northern mid-latitude ecosystems.

Zhongjie Yu, Timothy J. Griffis, John M. Baker