And neither is the ice on Greenland:
Evidence buried in Greenland’s bedrock shows the island’s massive ice sheet melted nearly completely at least once in the last 2.6 million years. This suggests that Greenland’s ice may be less stable than previously believed.
Two studies on this disagree as to the amount of melt, but they agree that the ice sheet mostly melted. Which is of course bad:
If all of Greenland’s ice melted, it would raise sea levels by seven metres. Models suggest that Greenland could become ice-free as soon as 2,500 years from now, depending on the concentration of greenhouse gases in the atmosphere3.
The latest papers add to a growing understanding of how Greenland’s ice has shifted over millions of years.
On the other hand, if this ice melted 2.6 million years ago, I’m going to assume that we didn’t do it. It also brings into question how well all the other studies took into account natural factors such as the sun, clouds and naturally occurring Co2 sources.