Climate change: Melting away under your feet
An ice-free North Pole could soon become reality. The consequences reach far beyond the Arctic
James Tulloch
© Plainpicture
If Peter Wadhams is correct, flags at the North Pole will soon have to be attached to buoys. For more than 40 years, the Cambridge physicist has been hitching rides on icebreakers and nuclear submarines, pitching camp on ice floes, observing the ebb and flow of Arctic sea ice. He is convinced that by, if not before, in summertime that ice will melt away.
To put this in perspective, in the, Arctic sea ice usually covered about 3.01 million square miles (8 million square kilometres) at its lowest ebb in September – an area the size of Brazil. These days, September ice extent is about half that (the record low was 1.3 million square miles (3.4 million square kilometres). In other words, the Arctic has already lost ice the size of the Indian subcontinent.
“It is a different world,” says Wadhams. “When I first went nearly all the ice was multiyear ice – heavy, thick, rugged stuff. It was very tough to travel on and very impressive. Now it is just first-year ice. There is nothing to it. It is very flat and thin, only a meter thick instead of three meters. In the past, we could camp on the ice and supply it by air. Now, if you set up a runway, the ice breaks up.”
Peter Wadhams
Leads the Polar Ocean Physics group at Cambridge University studying the effects of global warming on sea ice, icebergs and the polar oceans. This involves work in the Arctic and Antarctic from nuclear submarines, autonomous underwater vehicles (AUVs), icebreakers, aircraft and drifting ice camps. He has led over 40 polar field expeditions. He began his career in ocean science as a research assistant for a year aboard the Canadian research ship “Hudson” on the “Hudson-70” expedition which accomplished the first circumnavigation of the Americas.
A once-formidable landscape is wasting away: and there is nothing we can do about it. Hence the mournful title of Wadhams’ upcoming book: A Farewell to Ice (to be published in September).
“We are past the point of no return,” he says. “The Arctic is warming about three times faster than elsewhere. Every feedback is tending to accelerate warming and ice retreat. There is no countervailing force that is going to save the ice or bring it back.”
MELTING POINTS
The main culprit is warming air temperatures – aided and abetted by warmer water from the Atlantic Ocean infiltrating the Arctic, and new wind patterns that blow first-year ice out of the Arctic before it can thicken and become multiyear ice.
Feedbacks reinforce the cycle of decline. For instance, when sea ice retreats it leaves open water, which generates winds and waves. Waves penetrate and break up the ice, a process Wadhams is studying with the US Navy.
The downward trend continues. As of July 18, after the warmest Arctic winter on record and record low sea ice extents in every month except March, the National Snow & Ice Data Center shows this year’s sea ice extent is neck-and-neck with the record low levels.
Should ice extent dip below 1 million square kilometres (386,000 square miles), the Arctic would be considered sea ice-free.
“September ice is going to vanish first but July, August and October will not be far behind,” says Wadhams. “It will be like the Antarctic where you have an ice-free summer about four months long.”
CONSEQUENCES FOR CLIMATE AND SEA LEVELS
Although that may be great news for cargo ships shuttling between Asia and the West, for people affected by climate change it is very bad news indeed. Wadhams identifies three consequences.
First and foremost is the darkening of the Arctic, which accelerates global warming. White ice reflects the Sun’s heat like a giant parasol – the albedo effect. When the parasol contracts it leaves dark open water, which absorbs heat. Warmer water inhibits ice formation and heats the air over Arctic coastlines, encouraging snowmelt and darkening the land. Earth’s reduced albedo is a major contributor to global warming, say researchers at the Scripps Institution of Oceanography. They calculate that since the darkening Arctic has had the same effect as one quarter of global CO2 emissions.
Based on preliminary findings from his ongoing research, Wadhams is even more pessimistic. “That paper is outdated because it didn’t take account of snowline retreat in summer,” he says. “If you add the two effects together, then it is equivalent to about half of the effect of CO2 emissions.”
Second is the threat of a gigantic release of methane, a greenhouse gas more than 25 times as potent as CO2 over a 100-year period. As the Arctic Ocean warms, it thaws seabed permafrost which releases trapped methane. Recent expeditions have discovered methane plumes in the East Siberian and Kara Seas, says Wadhams, who calculates that Arctic methane emissions could add 0.6 degrees Celsius to global temperatures.
Third is accelerated global sea level rises – almost certainly more than a meter this century – due to warmer Arctic air melting ice on land, particularly the Greenland ice sheet.
ARCTIC DEATH SPIRAL OR ALARMISM?
Wadhams’s predictions are controversial, some say alarmist. He attracts criticism for the severity of his warnings and the frequency with which he sounds the alarm. This is largely because he is far more pessimistic than the consensus view represented by the Intergovernmental Panel on Climate Change (IPCC) – Arctic sea ice will persist until mid-century at least.
What to do about it
Because the world is wedded to fossil fuels, Wadhams believes our only hope is geoengineering.
“Marine cloud brightening, where you inject water vapour into the bottoms of cloud to increase their reflectivity, could have an effect,” he suggests. This would increase the albedo effect, cooling the Arctic region. “If targeted right, you wouldn’t have to cool down the whole world to bring the ice back.”
Geoengineering methods like this can put a sticking plaster on global warming and protect us from its worst effects. But ultimately, the only way to save the world and bring us to a long-term sustainable climate future is to actually find ways of taking carbon out of the atmosphere (a process called DAC – direct air capture) at a reasonable cost. According to Wadhams, we need a massive research programme on DAC – it is by far the most important field of research for the human race.
So is he guilty of crying wolf?
“I haven’t cried wolf yet,” he chuckles. “My cry has been that the trend leads us towards zero ice or soon after. If we don’t go to zero or a year or two later then my predictions will be unfulfilled.” That said, he argues that the IPCC’s stance is preposterous.
“You can’t go to the Arctic and see the trends over 30 years and not arrive at zero ice very soon. So how come they are predicting to ? Because their models aren’t any good. My opponents are not so much climate change deniers but climate modellers who don’t go to the Arctic.”
Wadhams has been going to the Arctic ever since he landed a research assistant’s job aboard the first ship to circumnavigate the Americas in. Over that time he has seen Arctic peoples forced to move villages away from fast-eroding coastlines. If his predictions about “the Arctic death spiral” are correct, the impacts will uproot many more people worldwide.
This summer, he scheduled a research trip to Greenland but had to postpone until next year. The reason: not enough ice.
