As Jason said, balanced carbon emissions. The problem is that there were swamps in Alaska which made the oil field under the permafrost that many don't want to touch. I don't think we want the ice caps to melt like it was millions of years ago even with balanced carbon emissions. I am more concerned with today, not millions or billions of years ago. There are many factors which effect global warming that are unknown. Maybe we have been preventing an ice age? Who knows? I don't pretend to know the answer but I believe many scientists who make a living with CO2 research don't know either. Now just my 4 cents worth.