Important Global Warming Article

Oy. Here we go again. Two separate threads all tangled and mangled up.

The first relates to the long-term (c. 400k years) data asserting a lag of some hundreds of years between temperature and CO2, where CO2 varies over an interval of more or less 200 to 280 ppm -- based on lagged regression. The equivalent temperature variation "associated" with the CO2 variation is of the order of 10C degrees.

Here's the problem. The unstated assumption behind lagged regression is causality. The demonstrated(?) fact is only that temperature goes up and down (a lot!) and afterwards CO2 goes up and down over a range half that of where we are today. I don't think anyone asserts that the 80 ppm CO2 increase is anywhere enough to cause a 10C temperature increase! Indeed, the singular fact we're not frying at almost 390 ppm today is pretty good evidence that the regressed variables are more likely colinear rather than correlated. Something is causing CO2 to go up after temperature.

The other argument looks at the short term record, asserting rather large temperature variations over the last few millenia that can't be explained by obvious CO2 changes. Same problem and same counter-argument.

Frankly if some exogenous phenomena did cause the Medieval Warm Period to be 3C warmer (questionable), that's hardly reassuring. The implication is that whatever caused it could happen again, possibly someday superimposing its effects on top of greenhouse gas warming.

I'm no paleo-climatology expert, for sure, but some of these attempts to "disprove" greenhouse gas warming just make me gag.
 
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