Cheeky C(h)MIP (part 1)

Pilfering the CMIP6 atmospheric CO2 data

In HADCRUT Global Temperature Anomaly (part 1) I introduced folk to the world reference atmospheric CO2 laboratory at Mauna Loa, a rather big, belching volcano in Hawaii. No sooner had I done this when I launched into a scatterplot of the HADCRUT5 global temperature anomaly plotted against atmospheric CO2. But I am forgetting my manners, and so today I shall formally introduce you to the monthly data series produced by this facility. Here it is:

We may note it kicks-off in March 1958 and bends slightly upward, revealing acceleration in the CO2 record. We should also note the jagged pattern, this being the seasonal variation in CO2.

Atmospheric CO2 reaches a peak during winter when the deciduous forests of the Northern Hemisphere shed their leaves and stop converting CO2 into sugars and starches, and when evergreens take a snooze during the colder winters. Despite Mauna Loa being stuck over in the Pacific at 19°32’N, and +3,700Km from the nearest substantial landmass, this natural patte…