Intense Warming Will Significantly Increase Cropland Ammonia Volatilization Threatening Food Security and Ecosystem Health

Elsevier, One Earth, VOLUME 3, ISSUE 1, P126-134, JULY 24, 2020
Huizhong Shen, Yilin Chen, Yongtao Hu, Limei Ran, Shu Kee Lam, Gertrude K. Pavur, Feng Zhou, Jonathan E. Pleim, and Armistead G. Russell

Cropland ammonia volatilization (VNH3,AG) is a major pathway of agricultural nitrogen loss. It remains unclear, however, how climate warming and human intervention (e.g., agricultural management) will affect VNH3,AG. Here, we use a fully coupled agroecosystem/chemical transport model and multiple climate projections to quantify the changes in climate-induced VNH3,AG over the US. We show that climate change under an intensely warming scenario will increase VNH3,AG by 81% (95% confidence interval, 69%–92%) from 2010 to 2100. The increase in VNH3,AG will cause a 10% loss of nitrogen applied, decrease crop yields by 540 Gg-N year−1, increase atmospheric burden of ammonia/ammonium by 18%, and increase ammonia/ammonium deposition to sensitive ecosystems by 14%. We have found that combining climate-adaptive agricultural practices with feasible mitigation measures can fully offset the warming-induced increase in VNH3,AG, saving 13% of applied nitrogen, increasing yields by 735 Gg-N year−1, and providing net benefits for air quality and ecosystem health.