Twenty-three million years ago, the Antarctic Ice Sheet began to shrink, going from an expanse larger than today’s to one about half its modern size. Computer models suggested a spike in carbon dioxide levels as the cause, but the evidence was elusive – until now. Ancient fossilized leaves retrieved from a lake bed in New Zealand now show for the first time that carbon dioxide levels increased dramatically over a relatively short period of time as the ice sheet began to deteriorate.
Continue to article...
No comments:
Post a Comment