Monthly Average Atmospheric N2O

What is the Monthly Average Atmospheric N2O?

This is the average amount of nitrous oxide (N2O) that is in the atmosphere in a given month. The monthly average highlights the seasonal variation. The graph shows the last 3 years to highlight the seasonal variation.


Nitrous oxide has a large warming effect, with a Global Warming Potential (GWP) that is 273 times greater than CO2. Like CO2, but unlike methane, it stays in the atmosphere for a long time, on average 116 years. Besides its warming potential, nitrous oxide is also important because it depletes the ozone layer, which protects us from the Sun’s ultraviolet rays.

Wikipedia: Nitrous oxide Atmospheric occurrence
IPCC: AR6, Full Report, Section 5.2.3.1 Atmosphere

Units and measures

The primary unit here is parts per billion (ppb), which describes the average concentration of atmospheric methane per year. The secondary unit here is megatonnes, which describes the average weight of atmospheric methane per year. We show this to be able to relate to emissions, which are commonly expressed in megatonnes.

Wikipedia: Parts-per notation
Wikipedia: Megatonne

Insights from this chart

There is a light global seasonal cycle, with higher growth rates between October and March and less growth between April and September. Seasonal variation occurs both in the natural surface emissions and in the natural breakdown in the stratosphere.

Wikipedia: Methane in Earth's Atmosphere
caltech.edu: Seasonal cycle of N2O: Analysis of data

About the data

The National Oceanic and Atmospheric Administration (NOAA) Global Monitoring Laboratory provides monthly atmospheric nitrous oxide data.

Data sources

Globally averaged marine surface monthly mean data ESRL's Global Monitoring Laboratory of the National Oceanic and Atmospheric Administration
Credits: Lan, X., K.W. Thoning, and E.J. Dlugokencky (2022): Trends in globally-averaged CH4, N2O, and SF6 determined from NOAA Global Monitoring Laboratory measurements. Version 2022-10, https://doi.org/10.15138/P8XG-AA10Update cycle: monthlyDelay: ~ 3 months