The Greenland and Antarctic ice sheets are melting faster.

Posted by Greg Laden on March 8, 2011
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These masses of ice are now contributing more new meltwater to the world’s seas than all other melting ice combined.

The Greenland and Antarctic ice sheets are losing mass at an accelerating pace, according to a new NASA-funded satellite study. The findings of the study — the longest to date of changes in polar ice sheet mass — suggest these ice sheets are overtaking ice loss from Earth’s mountain glaciers and ice caps to become the dominant contributor to global sea level rise, much sooner than model forecasts have predicted.

The nearly 20-year study reveals that in 2006, a year in which comparable results for mass loss in mountain glaciers and ice caps are available from a separate study conducted using other methods, the Greenland and Antarctic ice sheets lost a combined mass of 475 gigatonnes a year on average. That’s enough to raise global sea level by an average of 1.3 millimeters (.05 inches) a year. (A gigatonne is one billion metric tons, or more than 2.2 trillion pounds.)

The pace at which the polar ice sheets are losing mass was found to be accelerating rapidly. Each year over the course of the study, the two ice sheets lost a combined average of 36.3 gigatonnes more than they did the year before. In comparison, the 2006 study of mountain glaciers and ice caps estimated their loss at 402 gigatonnes a year on average, with a year-over-year acceleration rate three times smaller than that of the ice sheets.

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Total ice sheet mass balance between 1992 and 2009, as measured for Greenland (top), Antarctica (middle) and the cumulative sum of both ice sheets (bottom), in gigatonnes per year, as measured by the two different methods used by the researchers: the mass budget method (solid black circles) and time-variable gravity measurements from the NASA/German Aerospace Center’s Gravity Recovery and Climate Experiment (Grace) satellites (solid red triangles). Image credit: NASA/JPL-UC Irvine-Utrecht University-National Center for Atmospheric Research

This will result in a greater increase in sea level of the medium to long term than previously estimated. Unless you live in Kiribati, in which case you’ll be fine.

Lots more details here.

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Comments

  1. #1 Daniel A
    March 13, 2011

    This melting at such an alarmingly fast rate is very surprising and in fact scary. The fact that global sea level is rising by 1.3 millimeters on average per year is dangerous to mankind and our ecosystem. And that this rate of rise in sea level is continuously increasing is something that we should be worrying about. Al Gore’s The Inconvenient Truth also illustrates the effects of the melting ice caps on human civilizations. It is predicted in his film that in a short number of years, cities around the world will be underwater. It appears that, based on this article, these effects will occur even sooner than expected. I find it disappointing that many times throughout history and again in this situation, humans deal with large scale problems only once their effects are felt and something is needed to be done. This, among many other environmental issues, are unsolved and will remain that way until we are forced to make an ultimatum. Hopefully people with authoritative positions will soon realize a step should be taken in advance to prevent a bigger problem from occurring in the future. More worldwide collaboration on the topic would be a start.

  2. #2 Marcia
    April 23, 2011

    Do you ever look at Google Earth? What do you make of the profile in the ocean, near the North Pole; who’s face is that –God or the devil? Also what’s with the black holes up there.. Is the world ending next year? I have a bad feeling about all this bad weather.. I so hope I am wrong…I’m a worried realist mom..

  3. #3 seema
    June 26, 2011

    nice