OK, then tell me what kind of thermometers they were using 400,000 years ago? F? C? K?
Did they write it down in pencil or ballpoint pen?
It's strictly speculation, they have no better idea what the temperature was than they do the color of the Dinosaurs.
Extrapolating from co2 levels doesn't work, because there are more variables involved than a direct correlation of temperature and co2 levels.
That's not science, it's voodoo.
