Is the Arctic Sea Ice really recovering as the some people say?
Not, if you look at the evidence. Yes, if you listen to some "pundits" or some of the daily press.
The dramatic downwards trend in the annual summer extent of Arctic sea ice - and marginal increase in Antarctic sea ice have both sparked intense debate and commentary. Viewed in a global context, the amounts of polar sea ice are relatively small compared with the massive total volumes of ice in the land based ice caps of Antarctica, Greenland, and the Himalayas. If we take into account the observations of recent accelerating ice mass loss from these areas, plus the mean length, thickness and mass loss from the worlds glaciers (and we consider that the often cited Antarctic sea ice is significantly thinner on average than the Arctic sea ice, and much smaller in extent during the melt season), it is evident that the global reservoir of perennial ice is diminishing. Coupled with the evidence of mean ground permafrost temperatures in all Arctic regions rising towards critical melt threshold over the past three decades, the evidence of ongoing average ice melt is global in extent and is currently following an accelerating trend. The relatively thin layer of sea ice floating on the Arctic Ocean appears especially vulnerable, and the clear multi-decadal decline in summer extent has become one of the most compelling indicators of recent climate change.
However it has been claimed that since 2007 the Arctic ice has been recovering. What does the actual data from Arctic studies show? Here we look at recent data and multiple strands of independent evidence to see if this claim has any basis in reality. Temperature, almost by definition, is the main factor that governs seasonal melting and re-freezing of ice. The amount of Arctic sea ice can almost be regarded as a self calibrating proxy for regional temperature, but there are several inter-related dynamic factors driving the high latitude weather patterns, air and oceanic temperatures, currents, and thus ice area and thickness. These causal factors will be the subject of a future post. Certainly, average temperature over the central Arctic has increased more than in any other region of the planet over at least the last fifty years, and the average length of the ice melt season has significantly increased over the past three decades (Markus 2009, Howell 2009, Rodrigues 2009).
The “extent” of sea ice (usually defined as area of the ocean covered by more than 15% of ice) is most commonly used when discussing changes in Arctic ice. Unlike the Antarctic case, the growth of Arctic ice area in winter is constrained by the land masses which almost completely surround the Arctic Ocean.
Although at the end of March 2010 Arctic ice extent enjoyed a brief anomalous increase due to cold weather conditions in the Bering and Barents seas, this ice is thin and young, and though there is also an increased proportion of overall second year ice since 2009, much of this has formed North of the Fram Strait and also in a large lobe North of Alaska along with a proportion of the remaining multi-year ice. Based on recent patterns of ice melt and motion it is likely that the scene is set for significant loss through 2010.
Viewed in a global context the amounts of polar sea ice are small compared with the massive total volumes of ice in the land based ice caps of Greenland, Antarctica, and the Himalayas. The Arctic sea ice is a diminishing and progressively thinning layer floating on the Arctic Ocean, and this makes it increasingly fragile and vulnerable to a number of related mechanisms which are likely to further enhance ice loss. The consequences of this loss for the inhabitants of the region could be profound (Ford 2009).
Thanks for the nsidc.org link. Unfortunately your answer "yes" goes against their assessment. They say:
Is Arctic sea ice really declining?
Yes, the data show that Arctic sea ice really is in a state of ongoing decline. The reason we know this is because satellites offer us a long-term record. As of September 2007, the September rate of sea ice decline since 1979 was approximately -10 percent per decade, or 72,000 square kilometers (28,000 square miles) per year. Although the 2009 sea ice minimum was larger than the past two years, the rate of decline since 1979 increased to -11.2 percent per decade. September is the month that Arctic sea ice melts back to its lowest point, known as the annual minimum, and is an important indicator of overall ice conditions. However, sea ice in the Arctic is in decline in all months and the decline is greater and the rate faster than natural causes could account for.
- antarcticiceLv 71 decade agoFavourite answer
Try using the link Peter J supplied http://nsidc.org/arcticseaicenews/
Scroll down the page and take note of this graph
Which shows the trend of the last 30 years a little more data than 2 months
(funny how when I post NOAA data for these sort of time periods (1-3 months) deniers jump up and down and declare you can't use these sort of short term periods) (but that's denial for you)
Further down the NSIDC page you will find this graph
Which shows the percentage of ice related to it's age, the single year ice (in pink) is going to melt very quickly as summer returns and as the article states "multiyear ice has continued to decline" I guess Peter J didn't bother reading that far.
- Dana1981Lv 71 decade ago
No. The 'recovery' in sea ice extent is a very short-term effect.
"This March, low atmospheric pressure systems persisted over the Gulf of Alaska and north of Scandinavia. These pressure patterns led to unusually cold conditions and persistent northerly winds in the Bering and Barents Seas, which pushed the ice edge southward in these two regions."
"The late date of the maximum extent, though of special interest this year, is unlikely to have an impact on summer ice extent. The ice that formed late in the season is thin, and will melt quickly when temperatures rise."
The 'recovery' argument is no different whatsoever than the argument in January 2008 that global warming had been 'erased'. Two years later we're experiencing record high global temperatures. Not much of an eraser.
Apparently deniers don't learn from history. They should have been embarrassed to have made the 'global warming erased' argument 2 years ago (which almost every denier on this site did), yet now they're repeating the error with the 'sea ice recovery' argument. Both are based on 1 month's worth of data (or less). Not the brightest bulbs in the box, those deniers.
- endpovLv 71 decade ago
No, there may be ice forming in the winter months, but the ice rapidly melts during the summer months. This is where I am much more skeptical of those who are skeptical of climate change, global warming and the dangers they bring. They just do not seem to understand that glaciers and ice caps that haven't melted in thousands of years, not even in the summer months are now melting and melting permanently. You may see some ice in the winter, but not enough to reform a glacier or ice cap. This is just one of the things that confirm that the "pundits", as you have mentioned, really do not know what they are talking about...
And, yes, the Arctic ice is really declining...
- JimZLv 71 decade ago
Peter provided a link which showed the extent of sea ice is recovering yet you don't like it so you ignore it. Do you favor a return of glaciers with extents of ice to Chicago and New York. If not, then why do you fret over a little bit of sea ice melting? You may not of heard about it, but we have generally warmed in the last several centuries. When that happens, glaciers generally recede and sea ice is lessened. In no other time would any rational person fret or worry about that. We live in warm wonderful times. Hopefully it will persist and that sea ice will remain minimal.
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- Anonymous1 decade ago