Although we show that the models do an excellent job, our primary results are based on data. We know the ice sheets melted. We know how much warmth it took to melt them. And that...

We need to start serious measures to reduce greenhouse gases within the next decade. If we don’t do something soon, we’re committed to four to six meters (13 to 20 feet) of sea-level rise in...

If we decide to keep on the track we’re on now and just keep on warming, because of greenhouse gas pollution, then we could easily cook those ice sheets more rapidly.

As [Hurricane] Katrina pointed out, we only need a meter [about 3.2 feet] of sea-level rise to make much of New Orleans unlivable. The same goes for a number of coastal areas.

Although ice-sheet disintegration and the subsequent sea-level rise lags behind rising temperatures, the process will become irreversible sometime in the second half of the 21st century unless something is done to reduce human emissions of...

What we didn’t predict is that it would be so dramatic.

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...

A lot of the stories you read make it sound like there’s uncertainty. There’s not uncertainty.

After that we’ll be committed to multiple more meters of sea level rise that will occur at rates of up to a meter?or three feet?per one hundred years.

I believe the retreat of sea ice in the Arctic is very likely a manifestation of human-caused global warming. Global temperature increases are accelerating, and so is sea-ice retreat. Humans are almost certainly the cause...

It’s hard to imagine why we’re wanting to rebuild if we’re going to allow global warming.

Mother Nature is changing even faster than models suggested it would in the Arctic.

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.

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...

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...