A paper out this week by Gong et al. finds that anthropogenic nitrogen emissions have a net cooling effect of -0.34 watts per square meter. They write:
“Specifically, the long-lived greenhouse gas nitrous oxide (N2O) contributes to warming of the atmosphere, whereas short-lived ammonium (NH4+) and nitrate (NO3−) aerosols generated from ammonia (NH3) and nitrogen oxide (NOx) gases can scatter solar radiation and thereby cool the atmosphere. NOx furthermore plays a pivotal role in various atmospheric chemical reactions, regulating the lifetimes and thus mole fractions of other gases, such as the greenhouse gases methane (CH4) and ozone (O3). Furthermore, fertilizer application and deposition of atmospheric Nr [reactive nitrogen] on land and ocean can alleviate N limitation in terrestrial or marine ecosystems and facilitate carbon sequestration…”
https://www.nature.com/articles/s41586-024-07714-4
DB2