By Dan Alters
The last time carbon dioxide levels were this high, trees were growing at the South Pole. A shocking line, but true. A recent National Geographic article reports on these facts and more.
And what does it all mean? Well, unless something is done to reverse the course of greenhouse gas emissions, many birds of the northern hemisphere are marked for extinction, according to the National Audubon Society. And humans? More on that later.
Read more at Centre Daily Times.