Every once in a while, someone will try to argue with me that the observed rise in the concentration of CO2 is because it’s “measured on a volcano”. But is it? The most frequently cited CO2 measurements are from Dr. Keeling’s measurements on Mauna Loa. Yes, this is a volcano. But Keeling took measurements at other locations as well.
Scripps Institution of Oceanography had several monitoring sites scattered throughout the World, mostly on remote islands in the Pacific. The Mauna Loa record is just the one that extends back furthest in time. We can see that all of the observations show excellent agreement.
There is something remarkable about that graph: no matter where the measurements were taken, the CO2 concentration is always about the same. There are squiggles due to the annual cycle that aren’t the same, but that’s because of the location of the sites. The Antarctica station, (SPO – cyan), has almost no annual cycle because of its remote location.