What caused global warming 40 million years ago?

Whatever you think about today's prognosis for global warming, there's no denying that the planet has been a lot hotter in the past. Now we know some of that heat was generated by carbon dioxide emissions 40 million years ago. » 11/05/10 3:18pm 11/05/10 3:18pm

How flowers completely changed Earth's weather 100 million years ago

Wondering why the weather is so strange lately? Why it's raining all the time in certain parts of the globe, but really dry in others? It's all because of flowers. » 6/16/10 12:58pm 6/16/10 12:58pm