Arctic

Global warming IS a time bomb.

There may still be time to defuse it, but that requires policy-makers to take the actions that are needed, not the ineffectual actions they are discussing.

Despite the publicity that global warming has received, there is a large gap between what is understood by the relevant scientific community, and what is known by the people who need to know, the public and policymakers. Global warming is small compared to day-to-day weather fluctuations, so it is hard for people to recognize that we have a crisis – but we do.

The climate system has great inertia, caused, e.g., by the 4-kilometer-deep ocean and the thick ice sheets on Antarctica and Greenland, which have only partly responded to the human-made changes of atmospheric composition. That inertia is not our friend. It is a Trojan horse. By the time the public notices that change is underway the momentum of the climate system may be sufficient to guarantee much larger changes. The climate system can pass tipping points, such that large change continues out of our control.

The bad news is that we have already passed into a dangerous range of atmospheric carbon dioxide.

The good news is that if we act smart and promptly it is still feasible to achieve a safe level of atmospheric gases, and the actions needed to achieve that would have multiple benefits in addition to climate stability.

In his new book, A World Without Ice, geophysicist Henry Pollack explains the complex influences that Earth's ice has had on human survival, and that population growth and industrialization are now having on the survival of Earth's ice. Following is an excerpt.

By Henry Pollack

Just as the international financial system surprised the world with a major collapse in 2008, the global climate system, with its human component, is equally capable of serious surprises.

Lurking in the shadows of climate change is the possibility that the accelerations we now observe in the climate system are portends of approaching tipping points.

In my opinion, it is still feasible to solve the global warming problem before we pass tipping points that would guarantee disastrous irreversible climate change. But urgent strong actions are needed.

It is clear that the required course is technically feasible, and it would have great benefits to the public in developing and developed countries. The geophysical facts practically dictate the way.

Unfortunately, knowledge and understanding of the situation are not widespread. In addition, there is a minority of people, termed “fossil interests,” who benefit from business-as-usual. These fossil interests have enormous influence on governments worldwide, far outside their fair role in democracies.

While politicians around the world debate how to reduce human-caused greenhouse gas emissions, scientists are making some unsettling discoveries about another developing greenhouse gas problem: nature’s own emissions.

A study published this week shows that the amount of carbon locked in the Arctic permafrost is more than double previous estimates. Additionally, other research shows that the permafrost is thawing, meaning this enormous amount of carbon could be released into the atmosphere as the greenhouse gases carbon dioxide and methane.

The thawing of the permafrost is especially dangerous because it could cause a domino effect of more warming that, for now, cannot be checked by human engineering or policy.

"We now estimate the deposits contain over 1.5 trillion tons of frozen carbon, about twice as much carbon as contained in the atmosphere", said Dr. Charles Tarnocai, Agriculture and Agri-Food Canada, Ottawa, and lead author of the study, published in Global Biogeochemical Cycles.

As long as permafrost is frozen, the carbon in the soil is locked up.

But when it thaws, the carbon becomes exposed, and microbes called methanogens break down the carbon and release methane, a greenhouse gas that is 20 times more effective at trapping heat than carbon dioxide.

If you think the pollution in New York, Los Angeles or Detroit is scary, consider this: Arctic indigenous peoples often have levels of persistent organic pollutants (POPs) in their blood and breast milk that are 10 times higher than the residents of major American cities.

Individuals living near industrial hubs expect to bioaccumulate a certain amount of toxic chemicals, but for aboriginal peoples living near the Arctic Circle, thousands of miles from the sources of these chemicals, the levels are both astonishing and disturbing.

The pollution is the result of what scientists call the “grasshopper effect”, in which transboundary pollution, dispersing at the point of origin and driven by wind, re-volatilizes (or comes down to earth and oceans) thousands of miles away in the Arctic.

“All indications are that levels of POPs are increasing very dramatically in the Arctic,” says Pamela K. Miller, the executive director of Alaska Community Action on Toxics.

“A warming planet, and certainly a warming Arctic, is only going to enhance the mobilization and transport of these chemicals into the Arctic.”

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• Jeanne Roberts's blog
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The news from the poles has been grim lately.

In Antarctica, scientists are closely watching the Wilkins ice shelf after its last remaining ice bridge fractured. The massive ice shelf, the size of Connecticut, was already floating so it won't raise sea levels as it breaks up in the ocean, but its demise is a harbinger of what could come for land-base ice sheets.

On the opposite end of the globe, satellite records released today reveal that 2008-09 was another bad winter for the thinning of the Arctic sea ice. The ice cap is thinning, and a decade-long trend of melting sea ice shows no sign of stopping.

Secretary of State Hilary Clinton cited those conditions as she called on participants at the Antarctic Treaty Consultative Meeting and Arctic Council today to increase protection of Earth's polar regions. The Obama administration is urging strict limit on Antarctic tourism and increased environmental research in both regions.

"We are reminded that global warming has already had an enormous effect on our planet, and we have no time to lose," Clinton said.

Anybody who is paying the slightest bit of attention knows that Arctic summer sea ice is melting at a record pace because of warming of the atmosphere and the ocean. It is also accelerating because of feedback loops -- there's less ice to reflect solar radiation back into space and more dark water to absorb it. That means further warming and even more melting of the ice.

Now scientists have found another mechanism that is speeding the melting of the arctic: atmospheric circulation. A recent paper published in Geophysical Research Letters, suggests that since 2001 a significant change has taken place in atmospheric circulation patterns during the Arctic freezing season. Whereas previously the Arctic winds travelled East-West, they are now cycling North-South and allowing warm air further north than ever before. The change helps to account for unusually high arctic surface air temperatures and increased sea-ice melt during the following summer, and points to further evidence that a tipping point has been crossed irrevocably.

The Independent (UK) reported in an exclusive story today that scientists have discovered "chimneys" of methane -- a greenhouse gas 20 times more potent than carbon dioxide -- rising from the melting Arctic seabed.

Scientists believe sudden release of stores of methane have in the past been responsible for rapid increases in global temperatures, dramatic changes to the climate, and mass extinctions.

Orjan Gustafsson of Stockholm University in Sweden, one of the leaders of the expedition, described the scale of the methane emissions in an email exchange sent from the Russian research ship Jacob Smirnitskyi.

"We had a hectic finishing of the sampling programme yesterday and this past night," said Dr Gustafsson. "An extensive area of intense methane release was found. At earlier sites we had found elevated levels of dissolved methane. Yesterday, for the first time, we documented a field where the release was so intense that the methane did not have time to dissolve into the seawater but was rising as methane bubbles to the sea surface. These 'methane chimneys' were documented on echo sounder and with seismic [instruments]."

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• David Sassoon's blog
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A fellow named Rolf Schuttenhelm has written up a proposal to build a 300 kilometer long dam in the Bering Sea to halt Arctic melting and permafrost thawing. He suggests that a 1.5 billion cubic foot wall of rock dumped into the sea would alter temperature, water salinity and water turbulence and help the Arctic stay frozen.

It's hard to know what to make of this proposal. A quick search on Google reveals a web site that identifies a Rolf Schuttenhelm this way:

Rolf is a Dutch student from the great city of Utrecht, where he spends his time studying physical geography and getting drunk with co-students. And, besides a few other hobbies, he likes to draw cartoons.

For the first time in human history, it has become possible to circumnavigate the Arctic ice cap.

New satellite images show that both the Northwest and Northeast passages are now ice free. Professor Mark Serreze, a sea ice specialist at the National Snow and Ice Data Center (NSIDC) said the images suggested the Arctic may have entered a "death spiral" caused by global warming.

The passages are open. It's an historic event. We are going to see this more and more as the years go by.

It's news that the UK press is carrying. Here's the story in the Independent; and here's the one in the Telegraph.

But here's the one in the Houston Chronicle: it doesn't mention the historic development, only that "climatologists were eager to see whether the record low of about 1.6 million square miles" of summer ice melt in the Arctic would be duplicated again this summer.