It’s been a while since we took a look at conditions on the Arctic ice cap. It would be nice to have some good news to pass along for a change, but that just doesn’t seem to be in the cards.

Out in the Arctic Ocean, about 200 miles (322 km ) north of the nearest human settlement, the future of the world’s climate is written in the patterns of ice patches on the water’s surface.

Old, “multiyear” ice — the glue that holds the polar ice cap together and forms the Arctic’s defense against encroaching warming — is slowly disintegrating, a process that is plain to see from the air.

Thick ice floes used to be kilometers (miles) wide just over a decade ago, said Jim Overland, a sea-ice expert with the U.S. National Oceanic and Atmospheric Administration, who has been surveying the site since the 1990s.

Now the narrow floes — with bright-white tops and a blue underwater glow — are just meters (yards) wide, observed Overland as he studied the patterns from the window of a U.S. Coast Guard C-130 aircraft.

The dense, high-quality ice is not coming back, Overland said.

The arctic ice cap is a major component of the entire world’s climate. If it disappears, and all evidence right now is that it’s a matter of when, not if, it could have a profound effect on the balance of weather patterns all around the Earth. That’s a future we are looking at unless real efforts are made to prevent it, and with all the opposition to doing anything from everyone who profits from things as they are, and the people they’ve convinced that global warming isn’t something we have anything to do with or can do anything about, it’s hard to see how that will happen.

I’m becoming more and more afraid that nothing meaningful will be done about what we’re doing to the environment until some major catastrophe occurs, and by then, for millions of people, it will be too late.

And it’s not because they’re looking for a good place to get a tan.

For only the second time in memory — the first was two years ago — thousands of walruses are coming ashore on Alaska’s Arctic coast. Chukchi Sea ice has retreated far to the north, beyond the productive waters of the continental shelf where the animals usually forage for food. Experts fear the walruses are expending much more energy foraging from shore — traveling farther than they would if they could haul out on sea ice over food beds. On Tuesday, the U.S. Fish and Wildlife Service moved Pacific walruses one step forward in the process of endangered-species listing.

The problem for walruses is that they are not able to swim indefinitely,m they need a place to rest between hunts. That place has historically been on the Arctic ice, but with the ice melting they’ve had to move to shore, where they’re more susceptible to predators and the effects of over-crowding. Add in the increased swimming distance to fishing grounds, and life is getting tougher for walruses in Alaska.

One reason it’s easy for some people, and politicians like Senator James Inhofe to deny the existence of global warming and climate change is that climate is a process that takes place over long periods of time, and there can always be short-term changes, like a cool Summer or early Winter that don’t seem to fit in with the idea of a warming planet.

But we’re getting more and more data about what’s happening to the Earth’s climate as a whole, and one of the most important pieces of evidence for global warming is the steady, over time, shrinking of the arctic ice cap.

Arctic sea ice has thinned between the winters of 2004 and 2008, with thin seasonal ice replacing thick older ice as the dominant type for the first time on record, according to the first basin-wide estimate of the thickness and volume of the Arctic Ocean’s ice cover.

The total area covered by the thicker, older “multi-year” ice that has survived one or more summers shrank by 42 percent over the four year period.

Based on data from a NASA Earth-orbiting spacecraft, the study provides further evidence for the rapid, ongoing transformation of the Arctic’s ice cover.

Anyone who doubts that the earth’s climate is getting warmer is, in effect, walking on thin ice. What generally happens is that such a person denies what’s going on until the ice breaks beneath them. In a larger sense, they are waiting for a catastrophe to wake them up to what’s going on. The rest of us don’t feel like waiting for that catastrophe to happen before we do something about it. That’s what the debate over global warming really comes own to, those of us who want to try and do something to avoid a catastrophe, and those who, for whatever reasons, will never really do anything until the ice collapses beneath their feet.

– image courtesy of the National Snow and Ice Data Center

For people interested in climate change, the extent of Arctic ice formation in the Winter and melt in the Summer has become a matter of annual interest. A good way to keep track of how the ice is doing is on the National Snow and Ice Data Center’s website, which features photos, graphs, and analysis of ice formation and what it could mean for the continued existence of the arctic ice cap. Here’s an excerpt from their latest report.

Arctic sea ice in 2008 was notable for several reasons. The year continued the negative trend in summer sea ice extent, with the second-lowest summer minimum since record-keeping began in 1979. 2008 sea ice also showed well-below-average ice extents throughout the entire year.

The ice cover in 2008 began the year heavily influenced by the record-breaking 2007 melt season. Because so much ice had melted out during the previous summer, a vast expanse of ocean was exposed to low winter air temperatures, encouraging ice growth. Although still well below average, March 2008 saw slightly greater ice extent at the annual maximum than measured in recent years. However, the ice was also thin: less than a year old and vulnerable to melting in summer. Even the geographic North Pole was covered with thin ice, capturing the imaginations of many in the media and general public.

If the possible melting of the North Pole has captured your imagination, head on over to the National Snow and Ice Data Center to get the latest news on ice conditions in the (mostly) frozen Arctic.

The latest information on the arctic ice cap goes down, I guess, as news that isn’t quite as bad as it might have been, not as good as was hoped.

Following a record-breaking season of arctic sea ice decline in 2007, NASA scientists have kept a close watch on the 2008 melt season. Although the melt season did not break the record for ice loss, NASA data are showing that for a four-week period in August 2008, sea ice melted faster during that period than ever before.

The reason it’s not as good of news as was hoped is that the Winter ice cap was actually fairly close to normal, and scientists had thought that might mean a less pervasive melt this Summer. No such luck.

“I was not expecting that ice cover at the end of summer this year would be as bad as 2007 because winter ice cover was almost normal,” said Joey Comiso of NASA’s Goddard Space Flight Center in Greenbelt, Md. “We saw a lot of cooling in the Arctic that we believe was associated with La Niña. Sea ice in Canada had recovered and even expanded in the Bering Sea and Baffin Bay. Overall, sea ice recovered to almost average levels. That was a good sign that this year might not be as bad as last year.”

While yearly results may change from time to time, there is no doubt that the overall trend is toward increased melting, and eventual total loss of the Arctic ice cap. The world that generations to come live in is going to be a very different place than the one we live in now, unless some drastic changes are made in the way we affect the environment, and soon.

For more information, check out NASA’s page on the latest arctic ice report, including pictures and an animation depicting the ebb and flow of the ice.

A couple of stories popped up today about greenland and the Arctic Ocean. In case you’re wondering, the ice is still melting. Fast.

Rapidly melting ice on Alaska’s Arctic is opening up a new navigable ocean in the extreme north, allowing oil tankers, fishing vessels and even cruise ships to venture into a realm once trolled mostly by indigenous hunters.

The Coast Guard expects so much traffic that it opened two temporary stations on the nation’s northernmost waters, anticipating the day when an ocean the size of the contiguous United States could be ice-free for most of the summer.

I bet the chance to be among the first to traverse the Arctic Ocean from one end to the other wil be a pretty popular cruise opportunity.

Meanwhile in Greenland, the ice is cracking.

In northern Greenland, a part of the Arctic that had seemed immune from global warming, new satellite images show a growing giant crack and an 11-square-mile chunk of ice hemorrhaging off a major glacier, scientists said Thursday.

And that’s led the university professor who spotted the wounds in the massive Petermann glacier to predict disintegration of a major portion of the Northern Hemisphere’s largest floating glacier within the year.

The major drama of our times is being played out in the landscape and seascape of what were once the most isolated and desolate places on Earth.

For years now estimates of when the arctic ice could melt and open up the ocean have been continually moved forward. Now the estimate is about as forward as it can get. It could happen this Summer.

It seems unthinkable, but for the first time in human history, ice is on course to disappear entirely from the North Pole this year.

The disappearance of the Arctic sea ice, making it possible to reach the Pole sailing in a boat through open water, would be one of the most dramatic – and worrying – examples of the impact of global warming on the planet. Scientists say the ice at 90 degrees north may well have melted away by the summer.

It’s true that last year the ice opened up enough to allow a ship to get through, but the scientists in the above article are talking about an open expanse of water, including a “totally ice-free North Pole”.

it may just be a dramatic enough event to draw the world’s attention and put to rest any remaining doubt about whether or not the world’s climate is changing.

There’s been quite a bit of talk lately about the plight of polar bears, shrinking arctice ice cuts in to their food supply and habitat. The latest round of stories seems to indicate that polar bears aren’t licked yet. Or in environmental parlance, threatened, not endangered.

The polar bear, a symbol of Canada’s far north as well as the effects of climate change on the sensitive Arctic environment, is in trouble, but it is not endangered or threatened with extinction, a Canadian advisory panel said on Friday.

The Committee on the Status of Endangered Wildlife in Canada gave the polar bear its weakest classification, that of “special concern”, but the Canadian government would nonetheless have to develop a management plan to protect the animals if it agrees with the new label.

But while polar bears, which get a lot of public attention, are maybe doing a bit better than thought, another large marine mammal, the narwhal, which doesn’t get anywhere the amount of press the polar bear does, is facing tougher times.

The narwhal, a whale with a long spiral tusk that inspired the myth of the unicorn, edged out the polar bear for the ranking of most potentially vulnerable in a climate change risk analysis of Arctic marine mammals.

The study was published this week in the peer-reviewed journal Ecological Applications. Polar bears are considered marine mammals because they are dependent on the water and are included as a species in the U.S. Marine Mammal Protection Act.

Narwhals are more dependent on a heavy ice cover in the Arctic, so changing conditions could affect them harder than some other animals, like polar bears. Whatever happens, there’s no denying that life is changing for a lot of animals that have made the arctic ice their home. It’s a way of life that quite really could disappear in our lifetimes.

There was a lot of talk this year about the dramatic increase in the rate of melting ice in the arctic. It’s winter in the arctic now, but on the other end of the world there’s growing evidence that the antarctic ice cap is also starting to see an increase in the amount of melting ice:

Climatic changes appear to be destabilizing vast ice sheets of western Antarctica that had previously seemed relatively protected from global warming, researchers reported yesterday, raising the prospect of faster sea-level rise than current estimates.

While the overall loss is a tiny fraction of the miles-deep ice that covers much of Antarctica, scientists said the new finding is important because the continent holds about 90 percent of Earth’s ice, and until now, large-scale ice loss there had been limited to the peninsula that juts out toward the tip of South America. In addition, researchers found that the rate of ice loss in the affected areas has accelerated over the past 10 years — as it has on most glaciers and ice sheets around the world.

In the past, ice melt in Antarctica has been mostly seen in the peninsula that juts off the continent towards South America. Now there has been a substantial increase in the amount of melting ice in western Antarctica, nearing the same levels as seen in Greenland. The difference in Antarctica is that much of the land is near sea level, and melting glaciers could much more easily slide off the continent and into the ocean than in the mountainous areas of Greenland.

Antarctica holds about ninety percent of the Earth’s ice, and while the current changes are affecting only a small percentage of the ice cap, the potential for dramatic change is clear. If a good chunk of the Antarctic ice cap slid off into the ocean, the affects would be world-wide and dramatic, a possible rise of sea levels by several meters. It;s looking more and more like the next fifty years or so will not be a good time to be living by the shoreline.

One of the problems with human behavior is that we tend to deal with major catastrophes after they happen, instead of planning ahead to deal with them before they happen. It’s hard to believe that the world we grew up in and live in could suddenly change in a way that changes millions of lives. But that’s exactly the possibility that looms before us now, and if we don’t start planning for it and doing whatever we can to prevent it, it’s going to happen.

The study that has sparked the news reports about Antarctic ice melt was conducted by Eric Rignol and associates and is due to be published in Nature Geoscience. An advance abstract of the report is available online.

Possibly the biggest environmental story of 2007 was the sudden and dramatic increase in the melting of the arctic ice cap. Blowing away all previous estimates, the Northwest Passage opened up and the latest projection has the ice cap melting completely in five or six years.

Naturally, scientists have been looking for an explanation, and one is starting to emerge. There may be a natural process involved, which taken together with man-made global warming is rapidly increasing the rate of ice melt in the arctic:

There’s a natural cause that may account for much of the Arctic warming, which has melted sea ice, ice sheets and glaciers, according to a study published Thursday in the journal Nature. New research points a finger at a natural and cyclical increase in the amount of energy in the atmosphere that moves from south to north around the Arctic Circle.

But that energy transfer, which comes with storms that head north because of ocean currents, is not acting alone either, scientists say. Another upcoming study concludes that the combination of both that natural energy transfer increase and man-made global warming serve as a one-two punch that is pushing the Arctic over the edge.

Rune Graversen, the Nature study co-author and a meteorology researcher at Stockholm University in Sweden, said a shift in energy transfer explains the thawing more, including what’s happening in the atmosphere, but does not contradict consensus global warming science.

Oceanographer James Overland, who reviewed Graversen’s study for Nature, said the research dovetails with an upcoming article of his which concludes that the Arctic thawing is a combination of the two.

“If we didn’t have the little extra kick from global warming then we wouldn’t have gone past the threshold for the change in sea ice,” said Overland, of the National Oceanic and Atmospheric Administration’s lab in Seattle.

Seems to me that the lesson to be learned here is that we still don’t know nearly enough about the causes of long-term climate change on Earth, and the ways those long-term processes can suddenly become short-term and catastrophic. Think, for example, of an abandoned car parked near a cliff. Years of rain, snow, and wind slowly move the car towards the edge of a cliff, then a bunch of kids come along and push the car over, with sudden and violent results for the car. Right now, we’re the kids giving the car a push, and we still haven’t figured out what happens when it hits bottom. In fact, some of us are still insisting the car will never fall.