Top ten weather stories for 2008: story two

Table of Contents

2. The Great Arctic Thaw Continues

Map of Canada with affected regions highlighted

While news of this year's ice loss in Arctic waters was not as stunning as last year, the trend to thinner and newer sea ice continued to surprise scientists around the world on many fronts:

  • On September 12, the sea ice extent in the Arctic Ocean dropped to 4.52 million square kilometres, coming close to last year's record low of 4.13 million square kilometres. Because ice was thinner in 2008 (less than a metre thick in places), overall ice volumes were less than that in any other year. That we got all the way to the second-lowest ice extent in the melt season, following the coldest winter in eight years, is remarkable and reflects the dramatic and sudden change underway at the top of the world.
  • For August 2008, the rate of sea ice melt was the greatest ever. Satellite images showed ice declining at a rate of 84,686 square km per day in August, compared to 63,191 square km per day a year earlier.
  • In 2008, vast stretches of water in the western Arctic, including the Beaufort Sea, were almost clear of ice. For the first time in recorded history, the navigable deep water routes of the fabled Northwest Passage over the top of North America, and the Northeast Passage over the top of Russia, were simultaneously free of ice. The year 2008 also marked the third consecutive summer that ships could easily navigate the Northwest Passage without hitting, or being blocked by, sea ice.
  • Canadian Arctic waters had much less permanent ice compared to the same time last year. Only 11 per cent of the Canadian Arctic waters comprised thick, multi-year ice. In 2007, old ice accounted for 15.5%. Most of the old, hard ice either melted or was flushed into the Atlantic Ocean, where it disintegrated. Today, more than 70 per cent of the Arctic sea ice is new, thin, salty and less than a year old.
  • More stunning news in 2008 was the dramatic disappearance of nearly one-quarter of the massive, ancient ice shelves on Ellesmere Island. The 70m-thick ice that covered 9,000 square kilometres a century ago has been chiseled down to just 1,000 square kilometres today, underscoring the rapidity and irreversibility of changes taking place in the North.
  • The calving of glaciers from Greenland led to nearly 1,000 icebergs off Canada's east coast, more than in the previous four years combined. Some icebergs made it as far south as the site where the RMS Titanic sank on her maiden voyage in 1912. At times, the sizable icebergs ceased production of the offshore oil fields.
  • Also noteworthy, the ice extent in the Baltic Sea was the lowest since records began in 1720. Latvia and most of Finland had their warmest winter since 1925. Norway's winter temperature was the second highest on record.

The unprecedented shrinkage of Arctic sea ice is a direct response to several years of favourable winds pushing old ice into the Atlantic. Also important: persistent, year-round warming in the North and a dramatic transformation of its surface from a highly reflective white snow or ice to dark, heat-absorbing sea water. Remarkable changes in the North are generally consistent with what scientists say we can expect as a result of climate change, but it comes much earlier than anticipated.

Scientists are still unclear how the rapid disappearance of the Arctic ice will influence weather in Canada's North or elsewhere in the world. The Arctic is the world's refrigerator and is a key factor in stabilizing global climates. Whether it will be prolonged drought in North America's Great Plains, warming of the Gulf Stream or increased storminess in Western Europe, it will be hard to deny that the vanishing ice at the top of the world is not, in part, a contributing factor.


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