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Dragonflies, open water reveal rapid Arctic change

Hudson Bay Mountains

Summer of 2007: A Time of Great Discontent

At the top of Hudson Bay, "we still have ice year-round, but there's been a little bit of changes. Different kinds of insects and different kind of birds that come around our area now." In the summer of 2007, both anecdotal and quantifiable evidence emerged that showed dramatic changes are taking place in the Far North at a faster pace than anyone imagined. "The summer of 2007 was stunning." The Northern Hemisphere is normally covered with 7.5 to 8.5 million square kilometres of ice on average. But on Sept. 17, 2007, scientists calculated that the amount of sea ice hit a new record low of just 4.2 million square kilometres. The fabled Northwest Passage is normally still choked with ice during the summer. At its usual low point, 14 per cent of the shipping route remains covered with ice, which prevents ships from passing unless escorted by icebreakers. This year, just 2 per cent was covered with ice, resulting in the second consecutive summer during which an unaided sailboat could pass through. "Along the 2,300 kilometres of the Northwest Passage you're going around ice for about 20 kilometres as opposed to the usual 400." Experts say it was the peculiar weather Mother Nature offered up last summer - whatever caused it - that is largely to blame for the recent UNUSUAL events. There was a high-pressure system that sat over the Arctic for much of the summer. It shooed away clouds, leaving the sun alone to beat down. That created higher ocean temperatures, which in turn accelerated the melt. UNUSUAL winds compressed sea ice, pushing it into the Transpolar Drift Stream and into warmer water where melting happened more quickly. On Melville Island north of the Arctic Circle, the mean temperature has been reported at just under 5 C in July since records were first kept in the 1950s. "What we observed through much of July [2007] were temperatures in the 15-to-20 C range. The highest temperature recorded was almost 22 C." While the summer melt usually sinks 50 centimetres into the permafrost, the melt depth was down at least a metre or more this year. That caused land to fracture, as well as large slides and flooding. One piece of land slid down a hill and dammed a river 200 metres across. "It's not surprising that this kind of thing could happen, but it's the scale and how rapidly it could occur. The impact of this, even if it's the only time it happens for the next decade, could be felt on the system for many, many years." This year, the dire warnings piled up. Until now, climate models were predicting that the Arctic would be free of sea ice in the summertime by 2040, 2050 or at the latest 2100. Now, 2030 is a more realistic date for that biggest melt of all. "We're a decade ahead of the worst-case scenario." "Sea-ice conditions would have to be substantially better than even the most conservative computer simulations of warming and sea ice" in order to prevent the projected drop in the number of polar bears. NASA warned that with so much Arctic ice melt, the planet may be hitting a tipping point. The thaw may become a self-sustaining acceleration. As the ice shrinks, so does the amount of reflective snow and ice, which in turn leaves the ocean to draw in more heat from the sun. Warmer waters, of course, melt ice more quickly. The Potsdam Institute for Climate Impact Research in Germany has pronounced that Arctic sea ice has "already tipped."

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