As was said before, the increased insolation relative to conditions today were due to differences in orbital eccentricity and axial tilt (the 20ka precession cycle changed which hemisphere was effected). Eccentricity was greater, so the orbit was more elliptical than now, and thus the Earth came closer to the Sun during the northern hemisphere summer. The higher insolation as a result of this was significant. Enough to be responsible for around 50% of the melt, the remaining melt is attributed to temperature rise and changes in albedo, particularly on the ice sheet during melt conditions.
Solar intensity variations during the solar cycle amount to changes in the order of 0.01%. It cannot account for these changes. Plus diminishing sunspot numbers are an indication of lower intensity periods which is out of phase with the Eemian conditions.
Cosmic rays caused quite a stir a while age, though research and shown that the effect is minimal and their role in cloud formation is less than originally proposed. Again, even if there were increased cosmic rays and their role was significant, the phenomena would be out of phase with the Eemian conditions as cloud generation due to increased cosmic rays would have a cooling effect.
I think you have the resolution of the ice core and stomatal CO2 record ass-about. Ice core records are annual for the shallower parts becoming decadal to multi-decadal at depth. The stomata records are temporally much coarser (Holocene studies have dating errors greater than ±100 years) and rely on correct identification and work best with a consistent single species. And yes there are discrepancies between stomatal and ice core CO2 for the Holocene and the Eemian. The stomata data appear to be much more variable, one Holocene study has CO2 variations ranging from 220ppmv to 400ppmv to 200ppmv in 300 years of which would require staggering amounts of CO2 to be added and then removed from the atmosphere in an unrealistic time frame 12,500 years ago.
But are you suggesting that the increase in Eemian temperature and sea levels can be better explained by a rise in CO2?
"I think what happened then is going to happen again. Or his happening again."
So what do you think is happening again?
