Those intent on denying human involvement in global warming often like to point to what natural causes that they feel explain away the phenomena. “It’s sunspots”, they’ll say, or “Shifts in the Earth’s orbit.”

Meanwhile, for climate scientists and the rest of us the evidence has been quite good for a while that global warming and climate change are being propelled by human activities like pollution from greenhouse gases such as carbon dioxide. Now, as if we didn’t have enough evidence already, a new study just released shows that if it wasn’t for us, the Arctic would be cooling instead of melting.

Arctic temperatures have been dropping for the last 2,000 years. Since 1900, temperature anomaly has turned positive, indicating temperatures started becoming warmer than the long term average, new research indicates. The study, which incorporates geologic records and computer simulations, provides new evidence that the Arctic would be cooling if not for greenhouse gas emissions that are overpowering natural climate patterns. The Summer temperature anomaly changed from about — 1 to + 1 which is a very large change.

The international study, led by Northern Arizona University and the National Center for Atmospheric Research (NCAR), will be published in the September 4 edition of Science. It was primarily funded by the National Science Foundation, NCAR’s sponsor.

“This result is particularly important because the Arctic, perhaps more than any other region on Earth, is facing dramatic impacts from climate change,” says NCAR scientist David Schneider, one of the co-authors. “This study provides us with a long-term record that reveals how greenhouse gases from human activities are overwhelming the Arctic’s natural climate system.”

“If it hadn’t been for the increase in human-produced greenhouse gases, summer temperatures in the Arctic should have cooled gradually over the last century,” says Bette Otto-Bliesner, an NCAR scientist who participated in the study.

So there you have it. We are influencing the climate not just enough to cancel out a two millenium long cooling trend, but we’ve actually reversed the process. Anyone denying human responsibility for global warming can now do so only as a matter of stubborn, ignorant belief. it has nothing to do with science, or the facts.

Another decision left-over from the Bush Administration is coming to a point where the new administration has to decide whether or not to support it. This time it’s proposed oil and gas lease, and the public comment period just ended.

More than 150,000 people have asked the federal government to halt plans currently underway to open 73.4 million acres of the Arctic Ocean to oil and gas leasing – the largest block of Arctic Ocean waters yet to be offered to the oil and gas industry.

In the public comment period that closed today, thousands of people from across the country asked the Department of Interior’s Minerals Management Service to call for a timeout on all industrial activity in the Arctic, until a precautionary conservation and energy plan is developed.

Of course, if the previous administration were still in charge, public comments wouldn’t amount to much in the face of the oil companies wishes. The new guys have talked a lot about change, here’s an opportunity to put it to the test.

There’s a new kind of cold war potentially brewing out there.

Russia will not allow itself to be left behind in the race to exploit the resources of the Arctic now being opened up by global warming, the Kremlin’s special representative for the region said in an interview.

Scientists say the ice is receding so fast that drilling for oil and gas high in the Arctic will soon become routine and cargo ships could sail between the Atlantic and Pacific along a new shipping lane much shorter than the routes used now.

Those lucrative prospects have unleashed fierce competition between nations with Arctic coastlines — led by the United States and Russia — to assert their influence.

“Fierce competition” between two old adversaries who once threatened each other with nuclear annihilation? Sounds like the kind of situation where the potential for conflict should be resolved before it happens. Luckily, it will be a few years at least before working in the arctic becomes routine.

And as far as a competition to exploit the arctic goes, if land area and coastline are any advantage, Canada should be a major player.

– 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.

as a greenhouse gas, methane makes CO2 look like a piker. The scary thought is there’s tons of the stuff locked up under the oceans and in the arctic permafrost. There’s already mounting evidence that global warming is beginning to release the methane.

The East Siberian Sea is bubbling with methane, a powerful greenhouse gas, being released from underwater reserves, according to a recent expedition.

This could be a sign that global warming is thawing underwater permafrost, which is releasing methane that has been locked away for many thousands of years.

If these methane emissions from the Arctic speed up, it could cause “really serious climate consequences,” said expedition member Igor Semiletov of the University of Alaska, Fairbanks.

Semiletov and colleagues have traveled along the Siberian coast—this year they covered 13,000 miles (22,000 kilometers)—while monitoring methane concentrations in the air and observing the seas.

“According to our data, more than 50 percent of the Arctic Siberian shelf is serving as a source of methane to the atmosphere,” Semiletov said.

One problem with following the news about global warming and climate change is that the more you learn the harder it is not to believe we’re already headed towards some kind of major catastrophe. A sudden, major release of methane from the arctic regions would be a worst-case, nightmare scenario, one that we better be doing everything we can to avoid.

Eric Larsen is an explorer who isn’t afraid to think big.

In 2009, renowned Arctic Explorer Eric Larsen will begin an unprecedented journey to the top, bottom and roof of the world. During a continuous 365-day period, Larsen will mount major unsupported expeditions to the North and South Poles and an expedition to the summit of Mt. Everest. This feat has never been completed in one year. To date, only 15 people (no Americans) in history have been to all three ‘poles’. The expedition’s objectives are:

Complete the first-ever expedition to Mt. Everest, the North Pole and South Pole in a continuous 365-day period

Promote clean energy solutions, advocate strategies for reducing carbon emissions post Kyoto 2012 and collect relevant scientific data

Produce a documentary film, book and educational CD-ROM that focuses on global warming, teamwork and the spirit of adventure

Develop a post expedition multi-media lecture series

To call this an ambitious undertaking is to be guilty of gross understatement. Eric is currently on his way to the South Pole, and one of the great things about the internet is that people can follow along. You can learn more about the expeditions, and follow along on the journeys at both Eric’s personal website, and at Save The Poles.

You’d think by now that the Interior Department and U.S. Fish and Wildlife would be starting to take the hint and do the right thing before being sued and forced into it by a court decision, but you’d be wrong.

The U.S. Interior Department will designate within two years protected areas of the Arctic that are considered critical habitat for polar bears and cannot be harmed by oil development as part of a legal settlement with environmental groups on Monday.

The Interior Department formally listed polar bears as threatened in May, but did not create protected areas for them.

it’s a game the Bush Administration has been playing throughout its term, using critical habitat designation as a way of getting around enforcing the regulations governing management of threatened or endangered species. it’s all about protecting the ability of oil companies in the arctic to “Drill, baby, drill” without regard to the impact on the land, water, or the animals who live there.

One U.S Fish and Wildlife official was good for a chuckle inducing quote, however.

The partial settlement, filed on Monday in U.S. District Court in Oakland, California, establishes a June 30, 2010, deadline for the critical habitat designation that was considered important to the species.

“We certainly intended to make a decision on critical habitat anyway,” said Bruce Woods, spokesman for the U.S. Fish and Wildlife Service’s Alaska headquarters.

You’ll notice he doesn’t say anything about when or where they intended to do that. If only our current wildlife officials were as good at managing wildlife as they are in parsing words, they just might not be getting sued all the time. And the rest of us could pay for protecting the outdoors and the wildlife that lives there, instead of having our tax dollars go towards defending lawsuits.

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.

Auyuittuq National Park in the Canadian Park has been closed for a very simple and unusual reason. It’s melting.

A major national park in Canada’s Arctic has been largely closed after record high temperatures caused flooding that washed away hiking trails and forced the evacuation of tourists, an official said on Friday.

Every year around 500 people visit Auyuittuq National Park, which covers more than 7,300 square miles on Baffin Island and is dominated by the giant Penny ice cap. The park is popular with hikers and skiers.

As a song once put it, “Now there’s your sign of the times.”