Ammonia has been feeding the world for decades as a fertilizer and is now rapidly emerging as a carbon-free fuel for shipping and industry. But if we focus only on CO₂ emissions, we risk creating new nitrogen problems, warns nitrogen expert Jan Willem Erisman in an article published in the journal One Earth.

Still, Erisman warns against focusing only on “green” production. “We mainly see ammonia as a climate-friendly fuel for ships, as it does not produce CO₂ emissions,” he says. “But during use, ammonia can leak into soil, water, or air, and burning it releases nitrous oxide and nitrogen oxides.”

Nitrous oxide is a powerful greenhouse gas, while nitrogen oxides contribute to air pollution, such as ozone and fine particles. Through rainfall, nitrogen oxides end up in seas and oceans, causing over-fertilization, which is another threat to biodiversity

NOX has a CO2e impact of 275x or thereabouts from memory. Atmospheric concentrations have been increasing alarmingly, see this chart, selects N2O from the drop down list

https://capegrim.csiro.au/