4 April 2016

As The Science Gets Better, The News Gets Worse on Sea Level Rise

Posted by Dan Satterfield

How Antarctica's rivers of ice will behave in a warming world has been the subject of much research and and answers are now being found. Dan's photo from high above Antarctica.

How Antarctica’s rivers of ice will behave in a warming world has been the subject of much research, and the questions are now starting to be answered. Dan’s photo from high above Antarctica.

I spent the weekend reading the new paper in Nature last week that made a lot of news. (Justin Gillis at The NY Times has an excellent summary of the paper here). If you missed it, the short version is that for the first time, researchers used a series of coupled models to produce a more realistic look at what will happen to Antarctica in the coming decades and centuries. There has been a lot of uncertainty about how quickly the ice shelves could collapse, and even a decade ago the IPCC was saying that there was too much uncertainty to forecast it reliably. Since then, the science has improved, and the news has gotten worse. 

Why Antarctic ice sheets could suddenly begin to break up. From NATURE.

Why Antarctic ice sheets could suddenly begin to break up. From Pollard et. al. in NATURE. Click for larger version.

The image above is from the Nature paper, and shows why the ice sheets there are so very sensitive to sea level rise. (See the graphic above from the paper that explains this well). These rivers of ice are held in place by a block of ice that is grounded below the water, and if it breaks up, then the ice will start to flow much more rapidly into the sea. You probably know that Antarctica holds a LOT of frozen water, but the paper found that Antarctica alone could raise sea level by a meter by the end of this century if greenhouse gases are not sharply reduced. There is a great deal of confidence in the model that the researchers developed, because it predicts well what happened during the last inter-glacial (115-130 thousand years ago), and also in a very warm inter-glacial, 3 million years ago. 

NASA has news (on their excellent sea level site) today about new research that can estimate the contribution of different ice sheets in Antarctic and Greenland to rising sea level. That paper is here.  I should mention that the Nature paper also was given excellent coverage in the Guardian in London and by Chris Mooney in the Washington Post. The NY Times, and these media outlets, have consistently published accurate summaries of  new science. This is in contrast to yellow journalism practiced by the once great Wall Street Journal recently. Their recent attack on Dr. Micheal Mann was a flat-out lie and kudos to him for calling them on it. They owe him a correction (and an apology), but I wouldn’t hold my breath. If you subscribe to the WSJ, you should ask yourself if you want news that tells you what you want to hear, even if it’s wrong, or would your money be better spent funding accurate journalism that searches for the truth.

Unfortunately we live in a time when a great many people choose the first choice, and not the second. Which makes the findings from the Nature paper all the more alarming, because time is running out to do something about it.