During a glacial circumstances favor stacking ice in the Greenland basin of attraction. During an inter glacial the opposite occurs. Also consider what the massive weight of the ice does to the shape of the basin over time. Slope or curve changes of the basin probably help determine when a transition occurs. Over time the Greenland basin will tend to sink during a Glacial under the added weight. Ice at lower elevations may more easily melt and sea water may undermine the ice if the land is pushed down far enough.
This is a work in progress. I am trying to combine what Wheeler said as seen here at about 24:00: https://www.youtube.com/watch?v=XDAJinQL2c0#t=1625 with the Lorenz butterfly.
The orbs are meant to represent the orbits around the global attractor as with a Lorenz butterfly. In A the global attractor is drifting warmer as seen by the excursions of the orbits into new territory. We can perhaps say something about the global attractor from what we see above the line. Thinking of what else might be happening, we have B. Maybe the orbital diameter is increasing while the attractor does not move. In C the attractor also does not move but changes its elliptical shape. C would explain steady low temperature records with increasing high temperature records.
A good explanation:
“For the doubled CO2 and the 2% solar irradiance forcings, for which the direct no-feedback responses of the global surface temperature are 1.2° and 1.3°C, respectively, the ~4°C surface warming implies respective feedback factors of
3.3 and 3.0 (5).” – Andrew A. Lacis, Gavin A. Schmidt, David Rind, Reto A. Ruedy
15 OCTOBER 2010 VOL 330 SCIENCE