Atmospheric Methane (CH4) levels, 1840–present

All CH4 concentrations are annual averages, except that the 2025 value is a preliminary projected estimate, based on partial-year data.

To see precise methane concentrations, hover your mouse cursor over the blue graph trace. (However, all values are shown with about one more significant digit than is warranted by the precision of the measurements, and the ice core values are less accurate than the Mauna Loa measurements.)

For a discussion of methane's atmospheric lifetime, radiative forcing, and warming effect, see:
https://sealevel.info/methane.html

Click here for a downloadable, bookmarkable image (or take a screenshot with PrtScn or the Windows Snipping Tool).

Average atmospheric methane levels are very slightly lower in the southern hemisphere, such as at Cape Grim, Tasmania.

1840-1992 data (in light blue) is from https://cdiac.ess-dive.lbl.gov/ftp/trends/atm_meth/EthCH498B.txt (ice cores), interpolated (saved here).

1984-present data (in dark blue) is from https://gml.noaa.gov/webdata/ccgg/trends/ch4/ch4_annmean_gl.txt (measurements at Mauna Loa Observatory, HI), except that the 2024 figure is preliminary, projected from NOAA's July seasonally-adjusted monthly Mauna Loa measurements (the “trend” column).

Here's another website with a nice graph of methane levels: methanelevels.org.

We also have a similar graph for carbon dioxide (CO2), and a combined graph with both CO2 and CH4.

 

SeaLevel.info

 

Last modified: 23-Dec-2025 (version 38)