Climate indicators · NOAA Global Monitoring Laboratory
Nitrous oxide (N₂O)
339.9 ppb
June 2026, global monthly mean. Annual mean 2001: 316.4 ppb. 2025: 338.9 ppb.
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What it measures
The share of nitrous oxide in the air, in molecules per billion, averaged over NOAA's global sampling network.
Why it matters
Nitrous oxide comes mostly from fertiliser and manure. It is the third most important greenhouse gas and also damages the ozone layer.
Source and method
NOAA Global Monitoring Laboratory. Global monthly means as published; the latest months are preliminary.
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