Interesting. Makes me wonder about all the fossil fuels the Mayans burned. What must their carbon footprint have been? And all those Mayan automobiles and coal-fired power plants. The pollution must have been incredible - to cause climate change. After all, aren't those the things that Gore and his pals have been telling us are causing climate change now and probably the end of our civilization?
Don't you think that a "smart" guy - a Nobel Prize winner even - would have sense enough to realize that if a pre-industrial civilization experienced climate change that that fact, if true, would cut against the current theory/belief that modern humans' carbon emissions are the cause of the "problem"?