Green Times

Global warming is hitting the Arctic harder and faster than scientists expected, causing unforeseen changes to the frigid region’s ice, wildlife, atmosphere and oceans, the conservation group WWF said.The most prominent differences observed over the last three years include a “massively accelerated” decline in summer sea ice and “much greater” shrinking of the Greenland Ice Sheet, the environmental campaign group, known in the U.S. as the World Wildlife Fund, said in a 123-page report today.

“We’re seeing more rapid temperature-warming,” Ted Scambos, lead scientist at the National Snow and Ice Data Center in Boulder, Colorado, said by phone. The best explanation is “a trigger from greenhouse gases,” he said. Scambos wasn’t involved in the WWF report.

Conserving Arctic ecosystems requires slashing emissions blamed for climate change and reducing human activities that threaten the region that stretches between the North Pole and the northern timberlines of Eurasia and North America, the WWF said.

“Whatever happens in the Arctic is of global concern,” Martin Sommerkorn, climate change adviser at WWF and the study’s author, said today in a phone interview from Norway’s Lofoten Islands, inside the Arctic Circle. “We’re going into a very uncertain future where we don’t understand the changes that are already happening with global climate change.”

Twice as Fast

Aside from greenhouse-gas emissions, other stressing factors affecting the Arctic include the construction of oil and gas installations, shipping, and contaminants including soot, Sommerkorn said. Governments, businesses, local communities and conservationists need to work together to manage the frozen north’s ecosystems, and help them adapt, he said.

The conservation group prepared its report by referring to recent papers in scientific journals such as Science and Nature and also to reports last year by the United Nations Intergovernmental Panel on Climate Change, which shared the Nobel Peace Prize with former U.S. Vice President Al Gore.

The UN panel said that temperatures in the Arctic are increasing at almost twice the global rate. The warmer weather is melting ice in the sea and in Greenland, which contains enough water to raise global sea levels by 7 meters (23 feet).

Sea ice shrank in September to the smallest area on record, covering 22 percent less of the ocean than the previous low in September 2005, according to the NSIDC. That means it’s not premature to start talking about a “tipping point,” beyond which seasonal melt has sufficient momentum that it continues even without further forcing by temperature, Scambos said.

Tipping Point

“There’s a good chance we have crossed already” a tipping point, Scambos said. “The models for Arctic sea ice extent anticipated that greenhouse gas-forcing along the lines of business-as-usual increases in the atmosphere would lead to an ice-free Arctic by around 2060 to 2080.

“The trend now appears to be more like 2030, and a number of folks are pointing out that the response is likely to be non- linear and could be potentially a rather abrupt transition to an ice-free Arctic Ocean in a decade or two,” Scambos said.

Melting of the sea ice doesn’t raise water levels because it already rests in the oceans. Melting of ice caps such as on Greenland does contribute to rising sea levels, though a complete melt of the ice sheet isn’t likely this millennium, according to the IPCC, which forecasts sea levels will rise by 18 to 59 centimeters (7 to 23 inches) by 2100.

Other effects observed in recent years include increasing temperatures in the Arctic, “pronounced warming” of the Atlantic Ocean adjacent to the Arctic, a warming of the permafrost and declines in some population groups of polar bears, according to the WWF report.

Polar Bears

One study “predicts that by middle of this century, polar bears will be restricted to the northern tip of Canada and the northern tip of Greenland,” Sommerkorn said. “What we are going to see is about a two-thirds reduction of the ice polar bear population.”

The study’s author also warned of the potential for changes in the Arctic to create so-called “feedback loops,” whereby warmer temperatures trigger changes that generate more warming. An example is the exposure of ocean by melting sea ice. The dark water absorbs more of the sun’s energy than the reflective ice. Another is the potential release of carbon locked up in permafrost soils, Sommerkorn said.

“The Arctic is the place that warms the fastest, and it’s the place where that warming can trigger these amplification feedbacks,” Sommerkorn said. “No other system will react that quickly with that high a potential of making things worse.”
Source: Bloomberg, USA