Nitrous oxide emissions grew 40 percent from 1980 to 2020, accelerating climate change

Human-caused nitrous oxide emissions stem mainly from applying nitrogen fertilizers and animal waste to farms and pastures. Credit: NOAA

Emissions of nitrous oxide, the third most important human-made greenhouse gas, rose 40 percent from 1980 to 2020, according to a new report by the Global Carbon Project. The new study, published today in the journal Earth System Science Data, finds nitrous oxide is accumulating in Earth’s atmosphere faster than at any other time in human history and its current growth rate is likely unprecedented in the last 800,000 years.

Nitrous oxide, or N20 is a long-lived, potent greenhouse gas that has been accumulating in the atmosphere since the pre-industrial era. Human-made emissions of N20 come mainly from applying nitrogen fertilizers and animal waste to farmland and pastures.

N20is much less abundant in the atmosphere than carbon dioxide or methane (the two primary human-made greenhouse gases), but its global warming potential is nearly 300 times that of carbon dioxide over a 100-year time scale. N20 is also a strong ozone-depleting substance.