Jonathan Overpeck
![Jonathan Overpeck](/assets/img/authors/unknown.jpg)
Jonathan Overpeck
amount both greenland high level necessary rise sea warming
We know when the sea level was that high in the past, and we know how much warming is necessary to get that amount of sea level rise from both Greenland and Antarctica.
advance climate good ice news saying sheets vulnerable warming
We're saying that this could come much faster. The ice sheets are more vulnerable to climate warming than we had thought. The only good news I see is that we know about it in advance and can do something about it if we want.
predict
What we didn't predict is that it would be so dramatic.
arctic close degrees faster results suggest threshold warmer warming wishful
The results suggest the threshold is close to the end of this century, and it could come sooner. The Arctic is already warming much faster than we thought it would. To think we're not going to get 4 to 5 degrees warmer in another 50 years is wishful thinking.
necessary warmth
This is a real eye-opener set of results. The warmth necessary to do this isn't all that great.
arctic equivalent greenland ice last melted present sea sheet three time warmer
This is a real eye-opener set of results. The last time the Arctic was significantly warmer than the present day, the Greenland Ice Sheet melted back the equivalent of two to three meters of sea level.