Major Crops Contribute Significantly to Global Greenhouse Gas Emissions

A recent study led by Cornell University and Land & Carbon Lab indicates that in 2020, croplands emitted nearly 5% of global net greenhouse gas emissions, surpassing those from global shipping and equating to emissions from tropical primary forest loss.

Four crops—rice, maize (corn), wheat, and oil palm—are responsible for 67% of these emissions. The primary sources include draining peatlands (35%), flooding fields for rice cultivation (35%), and the use of synthetic fertilizers (23%).

Draining peatlands exposes carbon-rich soils, leading to significant carbon dioxide release. Flooded rice fields emit methane due to oxygen-deprived conditions that favor methane-producing microbes. Synthetic fertilizers contribute to nitrous oxide emissions when excess nitrogen is converted by soil microbes.

The six highest-emitting countries—China, Indonesia, India, United States, Thailand, and Brazil—account for 61% of global crop emissions. China, Indonesia, India, and Thailand's emissions are largely due to rice production, while Brazil and the U.S. emissions are driven more by fertilizer use.

To mitigate these emissions, the study suggests adopting climate-smart agricultural practices tailored to local conditions, such as improved water and residue management in rice cultivation and optimized fertilizer application.