2010 Arctic sea ice


in Canada, Geek stuff, Politics, Science, The environment

The extent of Arctic sea ice has dipped below where it was at this time of year in 2007, the worst year recorded for sea ice. Within the next few months, we will see whether it goes on to set a new record low. If so, perhaps it could be the sort of dramatic event that drives people to take climate change more seriously.

It is important to understand that the maximum extent of sea ice during the winter is a less important climatic indicator than the minimum extent in summer. The Arctic is always going to be cold and dark in the winter, when it is hardly receiving any sunlight. As a result, at least a thin layer of ice will form, establishing a large extent of frozen ocean. What is vanishing is the multi-year ice, which endures from year to year. Climate deniers trumpeted how the maximum extent of ice this year was close to the 1979 to 2000 average, yet the major trend in ice extent and volume is ever downwards.

If the Arctic ends up ice-free in the summer, there will be numerous consequences. Species that depend on sea ice – including narwhals, seals, and polar bears – will be threatened. Also, migration between the Pacific and Atlantic will likely allow the emergence of invasive species. Because losing summer sea ice means losing a big white sheet that reflects sunlight back into space, it would also cause further warming.

{ 7 comments… read them below or add one }

R.K. May 27, 2010 at 11:38 am

perhaps it could be the sort of dramatic event that drives people to take climate change more seriously

This seems unlikely. The sort of people who care about Arctic ice are already engaged on the climate issue. For the public at large, it is too distant and abstract to act as a real motivator.

Milan May 28, 2010 at 10:51 am

Unfortunately, that is probably true.

That said, there may still be an important subset of people who:

a) Aren’t yet convinced that climate change is dangerous, and that aggressive action should be taken to stop it; and,

b) Could be convinced of that by Arctic sea ice vanishing at a frightening rate.

These could include some of the intelligent people who nonetheless believe that technology will magically save us, or that adapting to climate change will be cheaper and easier than stopping it.

'ereComes May 30, 2010 at 3:49 am

Yes the extent is now statistically well below 2007 levels and we haven’t yet reached the part of the year where the rate of loss is at its greatest. There appears to be a reasonable probability that 2010 will be another record year for Arctic sea ice minimums.

. June 15, 2010 at 5:41 pm

“Every month between June and September, the environmental arctic change programme of America’s Arctic Research Consortium releases a “sea ice outlook” in which teams of researchers estimate how much ice will be left by September. The 2010 numbers are expected to become public in the next week or two.

In 2009 more than a dozen teams took on the challenge, and all of them failed to one degree or another. The group that came the closest to predicting the September sea-ice minimum (which was 5.36m square kilometres) was the one from the University of Washington, which had the figure chalked in as 5.2m square kilometres, overestimating the extent of the melting by an area five times that of Belgium. The University of Washington’s team made that prediction by “heuristic reasoning”—aka educated guesswork. The teams that relied more on modelling the processes involved, or on statistics from years gone by, did worse. All the teams overestimated the ice loss, some of them by more than 1m square kilometres.

Will it ever be possible to model Arctic sea-ice decline accurately? One bedevilling factor is that weather plays an outsize role in sea-ice conditions. A couple of high winds here, an abnormal cold snap there, and ice cover that had looked fragile can suddenly appear robust. Last summer the weather in August and September was dramatically different from that in June and July, when the initial predictions were made, which probably partly explains why everyone overestimated the extent of the melt. The record-breaking low in 2007 came in large part from a pattern of atmospheric highs that settled over the central Arctic, with winds pushing ice away from the Siberian coast and sending warmer temperatures coursing northward. Weather patterns such as this simply cannot be understood well enough months in advance to help inform sea-ice predictions.”

. June 15, 2010 at 5:45 pm

Three views of sea ice

Category: climate betting • sea ice
Posted on: May 23, 2010 4:35 PM, by William M. Connolley

The troops are getting restive. What wil happen to this year’s sea ice? Rumours abound.

So, it is not too late to join in the great predict-sea-ice-this-year party. My entry this year is “the same as” last year: linear trend since 1979, this time *not* omitting 2007 or 2008. As I recall, last year RMG was kind enough to work out what that came to in real numbers; perhaps he will again. As before, the possibility of a bet only really makes sense if people actually think very differently from me: which would be, either they think that there will be substantial ice growth this year, or some sudden collapse.

So, there you go: usual money on offer, which is to say “unlimited”, in the sense that so far no-one has wanted to take me close to my limit. If you manage to get there I’ll let you know.

Milan September 15, 2010 at 10:08 am

As reported on Climate Progress, sea ice volume may have been at its lowest observed level ever this year. The amount of multi-year ice is also at a record low, though the extent of this year’s sea ice was greater than the all-time minimum in 2007:

. September 24, 2010 at 10:04 am

Arctic Sea Ice Volume Anomaly, via DeSmogBlog

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