CO2 Levels Highest in Two Million Years

What happens when carbon dioxide levels skyrocket? Most climate scientists think they know the answer: global warming.

But to determine just how high temperatures may climb and how climate patterns may shift, researchers may need to pinpoint, for comparison, a time in our planet’s past when a similar carbon dioxide jump happened.

Doing that may have just gotten a lot tougher

…The study team, led by geochemist B