The ice cover over the Arctic Ocean is continuing to get thinner, according to new data released in London on Thursday, which supports the theory that due to global warming the ocean will be largely ice-free in summer within a decade.
The Catlin Arctic Survey, completed earlier this year, provides the latest ice thickness record. The data collected by manual drilling and observations on a 450 kilometre route across the northern part of the Beaufort Sea last winter and spring suggests the survey area is comprised almost exclusively of first year ice.
This is a significant finding because the region has traditionally contained older, thicker multi-year ice, said a spokesperson of the international NGO WWF, which released the results of the survey. The average thickness of the ice-floes measured 1.8 metres, a depth considered too thin to survive the next summer's ice melt.
The findings were analysed by the Polar Ocean Physics Group at the University of Cambridge, led by Peter Wadhams, one of the world's leading experts on sea ice cover in the North Pole region.
"With a larger part of the region now first year ice, it is clearly more vulnerable," said Wadhams. "The area is now more likely to become open water each summer, bringing forward the potential date when the summer sea ice will be completely gone.
"The survey data supports the new consensus view, based on seasonal variation of ice extent and thickness, changes in temperatures, winds and especially ice composition, that the Arctic will be ice-free in summer within about 20 years, and that much of the decrease will be happening within 10 years.
"That means you'll be able to treat the Arctic as if it were essentially an open sea in the summer and have transport across the Arctic Ocean."
WWF warned that rapid warming in the Arctic risked the release of vast quantities of carbon stored in the seabed or in frozen tundra soils.
"The arctic sea ice holds a central position in our earth's climate system. Take it out of the equation and we are left with a dramatically warmer world," said Martin Sommerkorn from the WWF International Arctic Programme, which was a partner in the survey.
"Such a loss of Arctic sea ice cover has recently been assessed to set in motion powerful climate feedbacks which will have an impact far beyond the Arctic itself - self perpetuating cycles, amplifying and accelerating the consequences of global warming. This could lead to flooding affecting one quarter of the world's population, substantial increases in greenhouse gas emissions from massive carbon pools, and extreme global weather changes."
"Today's findings provide yet another urgent call for action to world leaders ahead of the UN climate summit in Copenhagen this December to rapidly and effectively curb global greenhouse gas emissions, with rich countries committing to reduce emissions by 40 percent by 2020."