Scientists split on ice melt impact

Faster than expected ice melting this summer prompts warning that the Arctic could be ice-free in the summers within five years

BY PJ HELLER | BOULDER, CO | August 16, 2008


The shore of the Arctic Ocean is shown here covered with snow and ice. The blue sky with clouds is reflected in the water strip located in the crack of the ice shield. Some forecasters are predicting the Ocean could be ice-free in the summers within five years.
Credit: George Burba

Will global warming cause the Arctic to be ice-free in the summer within five years?

Yes, say some scientists, who warn that the ice melt is occurring faster than previously predicted and will cause major environmental damage, ranging from changing weather patterns to rising sea levels which will threaten scores of Pacific islands and low-lying areas.

No, say others, who insist that global warming is nothing more than a scam and that the ice melt in the Arctic is something that simply happens every year.

The latest salvo in the ongoing debate came with a report in a British newspaper warning that the meltdown in the Arctic was occurring at an unprecedented rate and that it could be ice free in the summer of 2013.

If that were to occur, scientists believe it would be the first time in 125,000 years that the ocean was free of summertime ice.

Mark Serreze, a senior scientist at the U.S. National Snow and Ice Data Center (NSIDC) in Boulder, said a "reasonable" time line for a total summer ice loss would be 2030.

Even that estimate is down from previous predictions.

"Had you asked me and some of my colleagues a few years ago, we would have said you would have an ice free Arctic Ocean anywhere from 2050, 2070 to 2100, because this was pretty much what our climate models were forecasting," Serreze said.

"But we know we're losing the ice a lot faster than any of these projections," he said. "There seems to be some aspects of this big loss that we still don’t have a handle on — some processes that are missing that we don’t have a handle on — so every time we look at the problem we keep revising our numbers earlier and earlier.

"My view is that 2013 or five years is just too aggressive," he said. "I just can't see it going in five years."

Even so, in the first 10 days of August, the amount of Arctic sea ice had declined by 390,000 square miles, according NSIDC said. The loss was blamed on a series of strong storms that broke up thin ice in the Beaufort and Chikchi seas.

The decline comes after Arctic sea ice in 2007 fell to its lowest levels ever — 39 percent below the long-term average from 1979 to 2000 — based on satellite measurements that began in 1979. The decline has been estimated at as much as 50 percent since the 1950s.

Serreze said the 2007 record loss was caused by the "perfect storm" with a warm windy weather pattern that helped melt the ice.

"This year we didn't have a perfect storm," he added. "Either way, it's not looking good."

In announcing the 2007 results, Serreze said, "Computer projections have consistently shown that as global temperatures rise, the sea ice cover will begin to shrink. While a number of natural factors have certainly contributed to the overall decline in sea ice, the effects of greenhouse warming are now coming through loud and clear."

Others, however, have disputed that statement.

John L. Daly, a "greenhouse skeptic" who died in 2004, was among those who have insisted that science has it all wrong when it comes to global warming.

"There is nothing in the data to suggest anything but natural cycles at work. As we can see from recent history, both the extent and thickness of Arctic sea ice is certainly subject to variation," he wrote. "But it would be a mistake to assume that a brief period during which the Arctic is in a thinning cycle is anything more than that — a cycle. We know from past history that it has been subject to earlier retreats . . . "

John Coleman, who founded The Weather Channel and now works as a meteorologist for a San Diego television station, is among those who also insist global warming is bad science.

"It is the greatest scam in history," Coleman has repeatedly insisted. "I am amazed, appalled and highly offended by it. Global warming: It is a scam.

"There is no significant manmade global warming under way and the science on which the computer projections of weather chaos are based is badly flawed," he wrote on the station's Web site.

"The constant urgent message is that global warming is happening now, and as the Arctic ice cap melts the climate disaster is beginning to unfold before our eyes," he said.

Such reports, he maintained, were simply "not true."

"The simple meteorological facts are that the melt happens every year," Coleman said. "In the spring and summer some of the ice melts and in the fall and winter it reforms again."

Serreze says what skeptics such as Coleman and Daly fail to understand is the basic physics behind global warming.

"The problem with the naysayer arguments that this is just some 'natural cycle' is that they refuse to understand that climate doesn't just doesn’t change by itself," he said. "Something has to force it. We know what's forcing it.

"If they are to dismiss this huge body of evidence that we're seeing clearly now in response to higher greenhouse gas concentration, they have to come up with another mechanism," he said. "Simply dismissing this as a natural cycle is a cop out.

"They're dead wrong," Serreze added. "We know why we're losing ice, because it's warming up. The Arctic like the rest of the globe is warming. We always knew that the Arctic would be the place that would be really sensitive to change, that's where you see it first. It's just what were seeing. It's just that the pace of change is catching us by surprise."

Coleman's rap on global warming is also at odds with other scientists, including members of the Intergovernmental Panel on Climate Change, which was established by the World Meteorological Organization and the United Nations Environment Program.

In its latest report, it said that sub-regions of the Arctic (and Antarctic) "have shown the most rapid rates of warming in recent years. The impacts of this climate change in the polar regions over the next 100 years will exceed the impacts forecast for many other regions and will produce feedbacks that will have globally significant consequences.

"However," it noted, "the complexity of response in biological and human systems, and the fact that these systems are subject to multiple stressors, means that future impacts remain very difficult to predict."

Serreze said the ice melts would have both environmental and human impacts.

"The growing recognition is that losing that ice cover can have impact on weather that extends well beyond the Arctic," he said, noting that the actual implications for regions are still not clearly known.

"This is a line of inquiry that seems to be very much still very much in its infancy," he said. "The changes are happening almost too fast for us to keep up with what some of those implications could be. We're only just starting to learn."

A bigger impact would be from a human standpoint, as the Arctic becomes accessible to various countries, raising questions about sovereignty, ecological and economic issues, particularly oil and gas exploration.

In June, a study by NSIDC and the National Center for Atmospheric Research reported that the rapid loss of sea ice could more than triple the rate of climate warming over northern Alaska, Canada and Russia.

"The rapid loss of sea ice can trigger widespread changes that would be felt across the region," said Andrew Slater, NSIDC research scientist and a co-author on the study.

Serreze said he was not a "doom sayer" when it came to climate change.

"My view on this is, yes, climate change is here," he said. "It's not 20 or 30 years down the road. It's here and the longer we wait to do something about it the worse things are going to be."


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