Posted by & filed under Global Warming/Climate Change.

by Emily E. Adams and Janet Larsen, Earth Policy Institute

The North Pole is losing its ice cap. Comparing recent melt seasons with historical records spanning more than 1,400 years shows summer Arctic sea ice in free fall. Many scientists believe that the Arctic Ocean will be ice-free in the summertime within the next decade or two, and some say that this could occur as early as 2016. The last time the Arctic was completely free of ice may have been 125,000 years ago.


Late Summer Arctic Sea Ice Extent, 563-2012

Between March 20 and September 16, 2012, the Arctic lost ice covering 11.8 million square kilometers—an area larger than the United States and Mexico together, and more than in any year since satellite measurements began in 1979. At its lowest point, Arctic sea ice coverage dropped to 3.4 million square kilometers, just half the average minimum between 1979 and 2000. The 2012 minimum was 18 percent smaller than the previous record low of 2007, a drop akin to beating the world marathon record by more than 20 minutes—an extraordinary feat.


Average September Arctic Sea Ice Extent, 1979-2012

The Arctic currently undergoes an annual melt and freeze cycle, which begins in the spring when the North Pole tilts toward the sun, warming the Arctic air and water and melting sea ice and glaciers. As the sun sets over the region in the fall, the sea ice expands, continuing to thicken during the dark winter. Wind circulation patterns and storms affect exactly how much ice melts and freezes in a given year, but as temperatures have been rising over the last few decades, ice coverage in the Arctic has begun a marked decline, and in recent years the shrinkage has accelerated.


Year-round Arctic Sea Ice Extent, Historical Average and 2012

The melting of the Arctic ice cap exposes dark ocean water, which absorbs more of the sun’s energy than the reflective ice, raising regional temperatures. This in turn accelerates the ice melt and makes it more difficult for new ice to form. In these warmer conditions, the ice that does return during the winter does not grow as thick and is more prone to melting when summer returns. Throughout the 1980s, close to half of the winter ice had survived one or more melt seasons. But by the start of the 2012 melt season, only a quarter of the remaining ice was more than a year old. Because of the dramatic thinning, the total volume of sea ice is shrinking even faster than its area. In just the past 5 years the minimum volume of ice in the Arctic was slashed in half.


Average September Arctic Sea Ice Volume, 1979-2012

An ice-free Arctic could alter weather patterns around the globe. Furthermore, while the melting of floating sea ice does not directly affect sea level, the extra heat in the region is accelerating the melting of the Greenland ice sheet, a massive body of ice 3 kilometers thick. If Greenland were to lose all of its ice, sea level would go up by 7 meters. While that would not happen overnight, even a 1 meter rise in sea level, which we could easily see this century, would have devastating consequences for us all.

7 Responses to “Arctic Sea Ice in Free Fall”

  1. Øyvind holmstad

    I can ensure you the climate here has become completely mad. This summer Oslo had more rain than Bergen, the first time ever! We have summer in March and autumn in summer and so on. The old weather patterns are gone in just a few years.

    Reply
  2. Greg

    Record lows in the Arctic, balanced by record highs in Antartica (since satellites enabled accurate measurements in 1979) – I don’t think we need to worry yet.

    Reply
  3. Øyvind holmstad

    @Greg, we should not worry? Do you know that the capital of Greenland, Nuuk, this summer had a higher average temperature than Oslo? This has never happened before. Now ALL the low pressures of the Atlantic Ocean circulate above my poor country, they stop here because they are hindered by gigantic high pressures above Russia to continue their way to the West. So WE got all the rain that Russia so desperately need, suffering as they are from drought. While we drown they dry out of lack of rain.

    In addition the low pressures from the Atlantic Sea are driven farther north because of climate change. They all come up from the huge Atlantic Sea and stop just above my head. I can ensure you this summer has not been much of fun, the potatoes are drowning and the grains turn black.

    The only “good” thing is that electricity is almost for free now, as the magazines overflow constantly. But now they build several enormous power gates just through the famous Norwegian fjord landscapes to the European continent, so this want last long. What is awaiting us is expensive electrisity, destroyed fjord nature and everlasting rain. And I should not worry?

    Reply
  4. Aapo Leinonen

    This worrying. And because of these we really have to consider applying geoengineering methods quickly. I wrote a longer post were I stated my wiews more precicelly and argumented why we should use geoengineering to slow down or reverse the melting of the arctic. Of course, massive emission reductions and adapting permaculture forms of agriculture are necessary.

    You can read my arguments for geoengineerings in here: http://permaculturenews.org/2012/09/19/unintended-hazards-of-geoengineering/#comment-397116

    - Aapo

    Reply
  5. Abrahim

    Record lows in the Arctic, balanced by record highs in Antartica (since satellites enabled accurate measurements in 1979) – I don’t think we need to worry yet. ? ? ? ?

    Comment by Greg — October 13, 2012 @ 7:15 pm ? ? ? ?

    Greg where are you hiding – the Antarctic is warming up and losing ice at least as fast as the Arctic. Just Google Antarctic ice cap melting and see what you get. The Ice Shelves of the Antarctic are melting and thinning fast and with them comes the acceleration of the glacier outflows from the Antarctic Continent – a continental icecap that if it dissappears will raise sea levels over 300m & we have no need to worry ?? Really Greg ???

    Reply
  6. Øyvind Holmstad

    @Greg, you are right the ice is growing in Antarctica, but by far not enough to replace the loss of ice in Arctic. Further the growing ice in Antarctica is caused by climate change, as the temperate areas have become warmer, something that causes stronger inland winds in Antarctica, blowing the ice further out from land. You can read more about this here: http://www.forskning.no/artikler/2012/oktober/338038 (use Google Translate)

    Reply

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