Are We Failing the Global Warming Test?

This image shows the extent of Arctic sea ice as of Aug. 26. The orange line shows the average extent of ice at this time of year.

Photo: National Snow and Ice Data Center

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Air temperature in the Arctic in 2008 rose to a record 5 degrees (C) above normal, summer sea ice melted nearly to the record extent seen a year earlier, Greenland melted more than at any time in at least 30 years, and the warming of the ocean lead to "unprecedented" sea level rise. Creatures that live in the Arctic are suffering as a result, and the global warming bellwether threatens to cause a cascade of effects at lower latitudes, as the Earth's air conditioner sputters.

Such is the state of the Arctic, according to the government's latest Arctic report card. The report card doesn't give passing or failing grades. It just offers a summary -- "There continues to be widespread and, in some cases, dramatic evidence of an overall warming of the Arctic system." -- and a color-coded key for understanding how much we should be worried.

But even if the report doesn't say it directly, it's hard to read its proclamations about global warming influencing dramatic, unprecedented and potentially far-reaching changes there without coming to the conclusion that the United States and world is so far failing to confront global warming.

Here are the report's key findings, reprinted verbatim:

• Atmosphere
  Autumn temperatures are at a record 5º C above normal, due to the major loss of sea ice in recent years which allows more solar heating of the ocean. Winter and springtime temperatures remain relatively warm over the entire Arctic, in contrast to the 20th century and consistent with an emerging global warming influence.



• Sea Ice
  The continued significant reduction in the extent of the summer sea ice cover is a dramatic illustration of the pronounced impact increased global temperatures are having on the Arctic regions. There has also been a significant reduction in the relative amount of older, thicker ice.

• Wildlife
  Changes to Arctic wildlife populations and habitats, although mixed, present some cause for concern. Recent observations of key marine mammal populations indicate impacts to their populations and habitats may continue for some time. Reduced sea ice has already been implicated in lower body condition and reduced survival of polar bears in western Hudson Bay, and similar impacts are likely in some other sub-populations. With the record summer sea ice retreats of 2007 and 2008, walruses, in some regions of the Arctic, were forced to haul out along shores in unusually large numbers, triggering increases in trampling deaths in response to increased terrestrial disturbance. Long term impacts to this walrus re-distribution are also expected as habitats are unable to sustain the needs of concentrated walrus populations into the future. Recent estimates of wild caribou and reindeer indicate that these populations may be entering a period of declining numbers, with populations that have previously been increasing at a steady rate now showing signs of either peaking or beginning to decline. Most goose populations are experiencing increasing numbers. For some species found in the Barents Sea, near record warm water conditions are close to the limit of their adaptive capabilities.

  Given the threats (both observed and predicted) facing northern species and their habitats, there is justifiable cause for concern, particularly with regard to small or declining populations, as well as for those for which information is insufficient. For example, the lack of trend information for Arctic Char, which some northern communities greatly depend on, represents a significant knowledge gap. Another area of concern is the Barents and Bering Seas which are both experiencing ecosystem re-organizations which result in greater uncertainty for the future status of stocks. Consequently, there is a need to increase monitoring of these ecosystems for continuing change.

• Ocean
  In general, the Arctic Ocean continued to warm and freshen in 2007 under the influence of unusual atmospheric forcing and continued dramatic sea ice melt. These changes were accompanied by an unprecedented rate of sea level rise.

• Greenland
  Warming has continued around Greenland in 2007, culminating in record setting (since 1970s) melt area and amplified absorption of solar radiation. Greenland's largest glacier, among a majority of others, continued its retreat. The ice sheet lost at least 100 cubic km (24 cubic miles) of ice, making it one of the largest single contributors to global sea level rise.

• Land
  Land-based observations, while widely ranging, reflect the effects of a general warming trend. For instance, there was an increase in the relative greenness of the Arctic region, consistent with warming soil and air temperatures, earlier snow melt, and the expansion of shrubs and tree line to the north. Permafrost continues to warm, however the rate of warming in the 2000s is significantly slower than in the 1990s. There is a continued tendency for a decrease in the snow cover of the Northern Hemisphere in the months of April through October. Glaciers are shrinking in most of the world. The amount of river discharge to the Arctic Ocean is increasing.

National Snow and Ice Data Center

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