Abstract

Significance N 2 O has 300 times the global warming potential of CO 2 on a 100-y timescale, and is of major importance for stratospheric ozone depletion. The climate sensitivity of N 2 O emissions is poorly known, which makes it difficult to project how changing fertilizer use and climate will impact radiative forcing and the ozone layer. Here, atmospheric inverse analyses reveal that direct and indirect N 2 O emissions from the US Corn Belt are highly sensitive to perturbations in temperature and precipitation. We combine top-down constraints on these emissions with a land surface model to evaluate the climate feedback on N 2 O emissions. Our results show that, as the world becomes warmer and wetter, such feedbacks will pose a major challenge to N 2 O mitigation efforts.