[Dan Evans]

High carbon dioxide levels have , historically, always followed warm periods.......more living critters eating and (your own favorite term for flatulence goes here) "

I always assumed it was because warmer seas can't hold as much dissolved CO2.

[capt. norm]

I always assumed it was because warmer seas can't hold as much dissolved CO2.

Totally valid point, that walked right past me tonight.

With the Pacific waters dropping in temperature, and right now it's in the deeper waters, the ability of the ocean waters to absorb CO₂ increase substantially.

[cogitator]

I always assumed it was because warmer seas can't hold as much dissolved CO2.

Correct, and also due to increased bacterial respiration in bogs ocurring in permafrost as continental glaciers recede.

Glacial/interglacial periods appear to be primarily triggered by the points where Milankovitch cycles either positively or negatively superimpose (all 3 of them, usually). These points mark places where solar insolation will be rapidly increasing or decreasing over a relatively short (geologically) time interval. Once the cooling or warming has been initiated, CO2 feedback ensues, pushing the system warmer or colder.