Sorry there is no way to accurately measure CO2 levels beyond polar ice cap data(not millions of years) maybe a couple thousand at best. Why do people believe a theory and then do everything to prove it? If the earth was 10 million years old we would have 2 miles thick of meteorite dust. Also the seas would be a block of salt given the rate a sallination. I challenge people to look at information with an open mind and try and to understand the data. Theories are usually based on limited data and not on compilations of such. The simple fact is that we need to break away from relying on foreign energy sources, so we don't have to sacrifice our children to live stable lives.