Pagani : CO2 level in atmosphere portends major changes . ( 0.9˚F ) of the potential temperature rise . He says research on the past shows the dangers of high levels of greenhouse gases . 35 million years ago 's CO2 levels comparable to time when Mark Pagani had little ice , sea was 200 feet higher . Pagani : With more CNN , we hark back to when crocodiles and sub-tropical plants inhabited the poles .
Pagani : CO2 level in atmosphere portends major changes . He says research on the past shows the dangers of high levels of greenhouse gases . 35 million years ago 's CO2 levels comparable to time when Mark Pagani had little ice , sea was 200 feet higher . Pagani : With more CNN , we hark back to when crocodiles and sub-tropical plants inhabited the poles .