"A lot of people say it’s too late to debate this claim (CO2 causes global warming) ...
... (but ) there’s very little evidence that CO2 drives temperature when you look closely.
... Even after 1750 they move together 15% of the time, and apart the rest of the time.
... the analysis ... went back thousands of years.
From 7500 BC on, and especially about 4800 BC until 1500 AD, CO2 and temperature, or the proxies we hope represent them, moved in opposite directions for thousands of years.
How can it be, if CO2 is the “Principal Control Knob Governing Earth’s Temperature“?
... back when we didn’t even know why CO2 was rising except we knew it wasn’t human beings.
... the claim that CO2 drives temperature does not depend on there being two kinds, one natural that does not and one man-made that does.
The theory stands or falls by whether CO2 of any sort drives temperature.
And historically it does not.
... Once we get to 1750 ... Humans were releasing enough (CO2) to drive the increase.
... Well, from 1750 to 1850, using IPCC WG1AR5, PI says temperature kept falling.
And even Michael Mann agrees.
There’s another 100 years of rising CO2 and falling temperature?
... basically from the invention of agriculture until the invention of the telegraph, the planet saw rising CO2 and falling temperature.
So where did this idea that CO2 even correlates with temperature increase, let alone causes it, come from?
Perhaps the more recent past?
After 1850 we have even better data, in the form of direct if very patchy and incomplete thermometer temperature records, and some direct CO2 data too.
... (there are ) stretches when temperature does not rise (negative or neutral) and one such period is… 1850 to 1929.
... from 1930 to 1944 CO2 rises and so does temperature.
Except from 1945 to 1980, CO2 keeps rising but temperature does not.
It is basically flat (the data say slightly negative but we dispute the precision).
... from 8000 BC to 1980 AD there’s no reason, outside one anomalous 15-year interval, to think rising CO2 means rising temperature.
So where did the idea come from?
... from 1981 to 2000 both rose, and the AGW movement was born and grew into a giant in that brief period.
... From 2001 to 2012, CO2 surged onward and… temperature stalled again.
Even though CO2 was now rising faster than between 1981 and 2000.
Mind you from 2013 to 2019 CO2 kept rising, naturally ... And even faster. And temperature rose. Gotcha 2.0!
From 10,000 years of data, much of it speculative, we have 42 years with CO2 and temperature rising together and over 9900 years without.
... CO2 causes warming is a theory ... even looking just at 1750-2019, it was falsified for 228 years and corroborated for 42.
Which comes out to 84.45% vs 15.55%.
Not a bet you’d take with $100,
let alone your whole economy, is it?"