Peter Wadhams, professor of ocean physics at Cambridge, said cargo ships would no longer need to rely on special ice-breaking vessels to cross from the Pacific to the Atlantic via the Northwest Passage. The route would be ice-free for months every year, cutting more than 4800km from the normal journey from East Asia to Europe via the Suez canal.
“The North Pole will be exposed in 10 years. You would be able to sail a Japanese car carrier across the North Pole and out into the Atlantic,” Professor Wadhams said. “The ice will retreat to a zone north of Greenland and Ellesmere Island by 2020 and that area will be less than half the present summer area. The change in the Arctic summer sea ice is the biggest impact global warming is having on the physical appearance of the planet.”
This month, the National Snow and Ice Data Centre, which is part of the University of Colorado, said Arctic ice coverage was the third-lowest since satellite records began in 1979. The coverage was greater than in 2007 and last year largely because of cloudy skies during late summer. Each of the past five years has been one of the five lowest years.
Professor Wadhams, who was on board the submarine supervising sonar measurements of the ice, said Mr Hadow’s findings confirmed the underlying trend was towards increasingly thin and patchy ice cover.
Mr Hadow and his two team members spent 73 days between March 1 and May 7 this year walking 450km across the Arctic while taking measurements. They drilled 1500 holes and found the average thickness of ice floes was 1.8m. This was too thin to have survived the previous year’s summer melting and indicated the ice had been formed in open sea during the winter.
Mr Hadow said future expeditions to the Arctic in summer would need to change their techniques and equipment to cope with more frequent stretches of open water. “A hundred years ago, explorers used dogs to haul sledges and then we went through the stage of people hauling sledges,” he said. “Now we have people wearing immersion suits and needing to swim, with the sledge floating. I foresee a time when the sledge will become more of a canoe.”
Martin Summerkorn, climate change adviser to the WWF Arctic Program, said the loss of sea ice predicted by the study would have profound consequences beyond the polar region.
Without ice to reflect sunlight, the Arctic Ocean would warm faster, resulting in the release of greenhouse gases stored in the Arctic permafrost soils. These soils contain twice as much carbon as is in the atmosphere.
Mr Summerkorn said the warming of the Arctic surface waters would accelerate the melting of the Greenland ice sheet, speeding up the sea-level rise.
“This could lead to flooding affecting one quarter of the world’s population and extreme global weather changes,” he said.