[cogitator]

but it also happens to prove that global warming is a natural cycle, because all of the CO2 + high temp periods are before the Industrial Revolution...indeed, most of them are before we had civilizations. ... *It doesn't prove it, it only proves that at times of high temp we also have high CO2. The high temps could be causing the high CO2 by causing it to outgas from the increasingly warmer oceans.

A little research will demonstrate that previous glacial-interglacial cycles were initiated by maxima and minima of Milankovitch-cycle solar insolation variability. Once a warming or cooling trend was initiated (increasing solar insolation after a minima, decreasing solar insolation after a maxima) CO2 feedback amplified either trend. Solar insolation variability alone is insufficient to explain the full temperature range in the ice core record -- the only factor with sufficient radiative effects is atmospheric CO2.

That's why temperatures and CO2 move together, even though the initial rise in temperature precedes the initiation of increasing atmospheric CO2. (Also applies to a decreasing temperature trend.)

[Publius6961]

BUMP!