Arctic ice disappearance should be 'wake-up call'
The ice covering the search area for the two lost ships of Sir John Franklin's doomed Arctic expedition suddenly disappeared more than three weeks ago, eliminating any ice-related issues that might have hampered technologies deployed in the search.
"We were just lucky," said Bill Noon, captain of the Canadian Coast Guard icebreaker Sir Wilfrid Laurier. It was anchored in Victoria Strait, just west of King William Island, which is the base for the first part of this year's search operations.
"We know from our discussions with the Canadian Ice Service that as long as surface air temperatures remain above freezing, the ice cover will continue to reduce," Noon says.
The nearest ice now was 120 kilometres north of the search area.
"The high sea brought on by the high wind was responsible for a fast sudden reduction in ice concentration, not at all unusual for this area," Noon says.
But what is good for the Franklin search is not necessarily good for the planet, as decreased Arctic ice could accelerate global warming.
Noon points to Canadian Ice Service graphs that show conditions that are unusual. Ice cover in the Western Arctic this year is the lowest it's been in the past 20 years, and a third less than the average.
Even more striking, for the week of Aug. 27 , ice cover in the Western Arctic was 44 per cent less this year than the average for the same week over the past 20 years.
Decreased by almost half
In fact, Arctic ice everywhere is disappearing at a significant rate. Data gathered by satellite and planes flying over the ice, as well as submarines diving under it, indicate that the total volume of Arctic ice has diminished by almost half since 2004.
At the present rate, summer ice will disappear much sooner than previously estimated, scientists say.
"Our models of future climate, both in the Arctic and globally, are conservative when compared to the observations," says David Barber, Canada Research Chair in Arctic system science at the University of Manitoba.
"For example, the International Panel on Climate Change models don't predict a seasonally ice-free Arctic until sometime between 2050 and 2100. But our observations say this will happen much sooner. We are on a trajectory that will see a seasonally ice-free Arctic within the next decade or two. This will be the first time this has happened on Earth in a very long time," says Barber.
"Our observations show a much more rapid response to the build-up of CO2 [in the atmosphere] than we expected to find. This should be a wake-up call to the public and to policy-makers to increase efforts to address this global problem."
Barber says the shrinking Arctic ice has several impacts on the planet, both in the Arctic and globally.
"It takes much longer in the fall to form the sea ice, as you have to get rid of the heat from the upper ocean prior to freezing the surface again," Barber says.
"This delay in the fall freeze-up affects the circulation of both the Arctic Ocean and the atmosphere over the sea ice. This increases the strength of storms in the Arctic, which have impacts on local industrial development and traditional Inuit use of the ice."
Effects of the vanishing sea ice will be very widespread, says Barber.
"Weather in the Arctic can affect the climate in temperate parts of the planet. The Arctic Ocean doesn't ventilate the Atlantic and Pacific Oceans as effectively as it used to, and this leads to continued warming of these two large global oceans —therefore increasing global temperatures."
It is not only sea ice that is melting. Another major concern, says Barber, is melting glaciers, which means an increase in fresh water that enters the large oceans of the world.
This year, for example, Greenland's massive glaciers suddenly began melting in July, according to data from NASA (National Aeronautics and Space Administration), which termed it "a freak event."
"This causes sea levels to rise and has impacts globally in the form of storm surges," says Barber, who noted a good example of that being how Hurricane Isaac affected New Orleans.
Loss of both the polar icecap and glaciers would also mean less reflection, and more absorption, of the sun's heat, which could have a "snowball effect" on global warming.
"Methane can be released from sub-sea permafrost and this process appears to be accelerating," says Barber.
"This is of concern since methane is a much more powerful greenhouse gas than CO2. The take-home message here is that our CO2-enhanced warming of the Arctic could lead to much more warming globally, as the amount of methane emission to the atmosphere increases."
Data from the European Space Agency's CryoSat 2 satellite suggest that for the past eight years, 900 cubic kilometres of ice a year is disappearing from the Arctic. Recent satellite images of the entire polar icecap clearly show the shrinkage.
Seymour Laxon, a scientist at the Centre for Polar Observation and Monitoring in London, England, sees the potential for significant change in the Arctic.
"Very soon we may experience the iconic moment when, one day in the summer, we look at satellite images and see no ice coverage in the Arctic, just open water."
With files from CBC News