The folks who deny that the globe is warming are fond of saying the computer models that show how our climate is changing are wrong.  It looks like they may be right – but not in they way they intend. The situation may be much worse as in-depth review of paleoclimate data (information about the changes in the earth’s climate stretching back millions of years) suggests that CO2 “may have at least twice the effect on global temperatures than currently projected by computer models” – which would mean that we could see changes in global average temperatures by 2100 that would render large sections of the earth uninhabitable.

Scary stuff that is described quite clearly by Joe Romm on his authoritative Climate Progress blog.

This science reinforces, yet again, the need to take aggressive action on a wide range of fronts to slash greenhouse gas emissions.