Here’s the global average temperature anomaly since 1880 (let’s use the data from NASA, shall we?).
Now, I’ll add to that graph the data for atmospheric CO2 concentration. In fact I’ll plot (as a function of time) the quantity 0.0101 x CO2 – 3.265. The triangles in red are yearly average values measured at the Mauna Loa atmospheric observatory in Hawaii; the blue triangles are values measured in the Law Dome ice core (from Antarctica).
I could run statistical tests (OK, I already have) and confirm that the correlation between global temperature and CO2 is strong. It’s very strong. It’s most notable since about 1975; from then until the present, both CO2 and temperature have been rising.
Yet some people don’t think so. They look at the same graph — or a different graph (often one created by some climate denier) and say things like “no correlation between temperature and CO2 except for a brief period from 1980 to 1999″ and “there was a climate hiatus after 1999.”
Look at the graph. If you know how to test these propositions statistically, please do so. Please. Then ponder … what kind of thinker says those things?
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