| Slimebeast said: Also, I never understood what triggers the glacial-interglacial periods and the differences of at least 4 degrees Celcius (or is it even +6 degrees?). I also haven't got a good explanation for the lag in CO2 concentration to temperature if CO2 is supposed to be the driving force or trigger. |
There is probably a great many different factors that influence that.
As I said before the current landmass distribution does favor an ice age by itself and that seems to be the reason why the average state of earth in the last ~2.4 million years is a glacial period, yet when solar activity is high, the gulf stream strong, the earth-sun distance relatively small ( it's very constant to be honest, but there are ever so slight variances there) and maybe concentraton of climate active gases (CO2, methane, aqueous vapor,..) high enough then glaciers may melt faster in the (northern hemnisphere) summer than they are formed in the winter and if that continues long enough then the effect amplifies itself as less glaciers means less albedo, so more sunrays hit soil/rock or water and are converted to infra-red rays.
Additionally oceans and soil may store climate active gases, but frosted soil can't emit that again, so the less perma frosted soil there is the more of these stored gases can be released to the air and warmer oceans release more of these gases aswell as for example a lot of methane is stored as methane-hydrate, which destabilizes if temperatures increase (there are complex CO2 based mechanism in the oceans aswell).
And that again is probably the main reason for the CO2 lag - these gases are emitted much more easily if it's warmer. Volcanic activity, which can be another big source of those, ofcourse is totally unrelated to global mean temperatures though.
