Arctic ice cap to disappear in 20-30 years: study

Elodie Mazein Yahoo News 15 Oct 09;

LONDON (AFP) – The Arctic ice cap will disappear completely in summer months within 20 to 30 years, a polar research team said as they presented findings from an expedition led by adventurer Pen Hadow.

It is likely to be largely ice-free during the warmer months within a decade, the experts added.

Veteran polar explorer Hadow and two other Britons went out on the Arctic ice cap for 73 days during the northern spring, taking more than 6,000 measurements and observations of the sea ice.

The raw data they collected from March to May has been analysed, producing some stark predictions about the state of the ice cap.

"The summer ice cover will completely vanish in 20 to 30 years but in less than that it will have considerably retreated," said Professor Peter Wadhams, head of the polar ocean physics group at Britain's prestigious Cambridge University.

"In about 10 years, the Arctic ice will be considered as open sea."

Starting off from northern Canada, Hadow, Martin Hartley and Ann Daniels skied over the ice cap to measure the thickness of the remaining ice, assessing its density and the depth of overlying snow, as well as taking weather and sea temperature readings.

Across their 450-kilometre (290 mile) route, the average thickness of the ice floes was 1.8 metres (six feet), while it was 4.8 metres when incorporating the compressed ridges of ice.

"An average thickness of 1.8 metres is typical of first year ice, which is more vulnerable in the summer. And the multi-year ice is shrinking back more rapidly," said Wadhams.

"It's a concrete example of global change in action.

"With a larger part of the region now in first year ice, it is clearly more vulnerable. 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."

Doctor Martin Sommerkorn, senior climate change adviser for the World Wide Fund for Nature's international Arctic programme, said the survey painted a sombre picture of the ice meltdown, which was happening "faster than we thought".

"Remove the Arctic ice cap and we are left with a very different and much warmer world," he said.

Loss of sea ice cover will "set in motion powerful climate feedbacks which will have an impact far beyond the Arctic itself," he added.

"This could lead to flooding affecting one quarter of the world's population, substantial increases in greenhouse gas emission 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 United Nations climate summit in Copenhagen in December to rapidly and effectively curb global greenhouse gas emissions."

Arctic to be 'ice-free in summer'
David Shukman, BBC News 14 Oct 09;

The Arctic Ocean could be largely ice-free and open to shipping during the summer in as little as ten years' time, a top polar specialist has said.

"It's like man is taking the lid off the northern part of the planet," said Professor Peter Wadhams, from the University of Cambridge.

Professor Wadhams has been studying the Arctic ice since the 1960s.

He was speaking in central London at the launch of the findings of the Catlin Arctic Survey.

The expedition trekked across 435km of ice earlier this year.

Led by explorer Pen Hadow, the team's measurements found that the ice-floes were on average 1.8m thick - typical of so-called "first year" ice formed during the past winter and most vulnerable to melting.

The survey route - to the north of Canada - had been expected to cross areas of older "multi-year" ice which is thicker and more resilient.

When the ridges of ice between floes are included, the expedition found an average thickness of 4.8m.

Professor Wadhams said: "The Catlin Arctic 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."

According to Professor Wadhams, faster shipping and easier access to oil and gas reserves were among short-term benefits of the melting.

But in the longer-term, losing a permanent feature of the planet risked accelerated warming, changing patterns of circulation in the oceans and atmosphere, and having unknown effects on ecosystems through the acidification of waters.

Pen Hadow and his companions Ann Daniels and Martin Hartley endured ferocious weather - including a wind chill of minus 70 - delayed resupply flights and starvation rations during the expedition from 1 March to 7 May.

When I met them on the ice, as part of a BBC team that joined the pick-up flight, all three had lost weight and were evidently tired from the ordeal.

The expedition had been blighted by equipment failures. A pioneering radar system, designed to measure the ice while being dragged over the ice, broke down within days. Another device to measure the water beneath the ice never functioned at all.

Incremental step

The technical breakdowns forced the team to rely on hand-drilling through the ice which slowed progress and meant the team's planned destination of the North Pole had to be abandoned.

Pen Hadow admitted that the expedition had not led to "a giant leap forward in understanding" but had been useful as an incremental step in the science of answering the key questions about the Arctic.

His view was backed by Professor Wadhams who said the expedition had provided information about the ice that was not available from satellites and that no submarines had been available to science at that time either.

Pen Hadow said he was shocked by the image of how "in my lifetime we're looking at changing how the planet looks from space."

He also described how polar explorers were having to change their methods from the days when sledges could be pulled by dogs over the ice.

"Dogs can swim but they can't tow a sledge through water which is what's needed now."

"Now we have to wear immersion suits and swim and we need sledges that can float. I can foresee needing sledges that are more like canoes that you also pull over the ice."

Explorers: North Pole summers ice free in 10 years
Maresa Patience, Associated Press Yahoo News 14 Oct 09;

LONDON – The North Pole will turn into an open sea during summer within a decade, according to data released Wednesday by a team of explorers who trekked through the Arctic for three months

The Catlin Arctic Survey team, led by explorer Pen Hadow, measured the thickness of the ice as it sledged and hiked through the northern part of the Beaufort Sea in the north Pole earlier this year during a research project. Their findings show that most of the ice in the region is first-year ice that is only around 1.8 meters (six feet) deep and will melt next summer. The region has traditionally contained, thicker multiyear ice which does not melt as rapidly.

"With a larger part of the region now first-year ice, it is clearly more vulnerable," said Professor Peter Wadhams, part of the Polar Ocean Physics Group at the University of Cambridge which analyzed the data. "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."

Wadhams said the Catlin Arctic Survey data supports the new consensus that the Arctic will be ice-free in summer within 20 years, and that much of the decrease will happen within 10 years.

Martin Sommerkorn of the World Wildlife Fund said the Arctic sea holds a central position in the earth's climate system. "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," he said.

He added: "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."

Global warming has raised the stakes in the scramble for sovereignty in the Arctic because shrinking polar ice could someday open resource development and new shipping lanes. The rapid melting of ice has raised speculation that the Northwest Passage linking the Atlantic and Pacific oceans could one day become a regular shipping lane.

The results come as negotiators prepare to meet in Copenhagen in December to draft a global climate pact.

Arctic To Be Ice-Free In Summer In 20 Years: Scientist
Peter Griffiths, PlanetArk 16 Oct 09;

LONDON - Global warming will leave the Arctic Ocean ice-free during the summer within 20 years, raising sea levels and harming wildlife such as seals and polar bears, a leading British polar scientist said on Thursday.

Peter Wadhams, professor of ocean physics at the University of Cambridge, said much of the melting will take place within a decade, although the winter ice will stay for hundreds of years.

The changes will mean the top of the Earth will appear blue rather than white when photographed from space and ships will have a new sea route north of Russia.

Scientists say evidence of melting Arctic ice is one of the clearest signs of global warming and it should send a warning to world leaders meeting in Copenhagen in December for U.N. talks on a new climate treaty.

"The 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," Wadhams said in a statement. "Much of the decrease will be happening within 10 years."

Wadhams, one of the world's leading experts on sea ice cover in the North Pole region, compared ice thickness measurements taken by a Royal Navy submarine in 2007 with evidence gathered by the British explorer Pen Hadow earlier this year.

Hadow and his team on the Catlin Arctic Survey drilled 1,500 holes to gather evidence during a 280-mile walk across the Arctic. They found the average thickness of ice-floes was 1.8 meters, a depth considered too thin to survive the summer's ice melt.

Sometimes referred to as the Earth's air-conditioner, the Arctic Sea plays a vital role in the world's climate. As Arctic ice melts in summer, it exposes the darker-colored ocean water, which absorbs sunlight instead of reflecting it, accelerating the effect of global warming.

Dr Martin Sommerkorn, from the environmental charity WWF's Arctic program, which worked on the survey, said the predicted loss of ice could have wide-reaching affects around the world.

"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," he said.

"This could lead to flooding affecting one-quarter of the world's population, substantial increases in greenhouse gas emissions .... and extreme global weather changes."

Britain's Energy and Climate Change Secretary Ed Miliband said the research "sets out the stark realities of climate change."

"This further strengthens the case for an ambitious global deal in Copenhagen," he added.

(Editing by Jon Boyle)