When climate expert Gunter Weller first came to Alaska decades ago, he'd pour Scotch into ice-cube trays and watch the Arctic chill flash-freeze the booze into tasty little cubes on the short walk to a party. But over time, he says, the greenhouse effect has warmed Alaska more quickly than other parts of the world, and his Scotch seldom freezes anymore.
Such observable changes in everyday life on the edge of the Arctic are turning global-warming skeptics into believers, Weller says. They also are raising troubling questions in a place where the economy is largely dependent on oil production.
While experts estimate temperatures worldwide have increased about 1 degree in the last century, Arctic winters have warmed much more quickly, as much as 10 degrees in the past 30 years, Weller said.
"All the signals are very consistent," said Weller, a retired University of Alaska geophysics professor and executive director of Arctic Climate Impact Assessment. "It's warmer. There's less sea ice. Permafrost is thawing. Glaciers are melting. There's less river and lake ice. The whole physical environment has changed very dramatically."
The greenhouse effect - an increase in carbon dioxide in the atmosphere that traps heat - is strengthened in Alaska by prevailing winds that bring southern warmth north, Weller said.
Alaska has long been a hotbed of contrarian views on global warming. For one thing, it's difficult to get people who cope with months of bitter cold up in arms about warmer temperatures. Brush the snow off a car bumper and you might find an "Alaskans for Global Warming" sticker.
And then there's the oil industry. North Slope crude has been Alaska's economic lifeblood for more than two decades. Besides the industry's high-dollar wages, oil taxes and royalties fuel state government, relieving Alaskans of any personal state tax burden and fattening the Alaska Permanent Fund, a massive savings account that sends each resident an annual check. People don't like to hear what Weller had to say to a committee of the state Legislature recently:
"What we need to do really is stop burning of fossil fuels, and that is not an easy thing to do," Weller told the House Resources Committee. His presentation drew only a muted challenge from lawmakers who have hastened in the past to condemn global warming as anti-oil propaganda and embrace other theories.
"Why is yours so much more irrefutable?" asked Republican Rep. Joe Green, a retired petroleum engineer who represents part of Anchorage.
"I think there is no longer a controversy about the impact of the greenhouse effect on the climate," Weller replied.
"I certainly questioned the cause of global warming," said Rep. Hugh Fate, a Republican who figures the sub-zero winters at his home in Alaska's interior began to grow milder in the mid-1970s. "It's certainly real and we're going to have to address it."
But while Fate accepts the impact of increased carbon dioxide in the atmosphere, he still balks at laying the blame entirely on fossil fuels.
"There's no question we have elevated carbon dioxide. We need to certainly watch very carefully the emissions," Fate said. "Even if it were from natural causes, we don't want to exacerbate this. But we also have to be concerned about the cost of doing business. It's a balance we're going to have to attain."
The signs of warming are all around.
The start of this year's Iditarod Trail Sled Dog Race had to be moved north because warm weather made the trail too dangerous for the mushers and their dogs. In recent years, mushers have complained of the warm weather's effect on dogs bred to run in subzero temperatures.
The jackpot in the Nenana Ice Classic, a popular lottery based on the spring breakup of the Tanana River, has been going to people who guess the ice will break earlier in the year.
Winter sea ice in the Bering Sea, Chukchi Sea and Arctic Ocean is about half as thick as it was 30 years ago, Weller said, perhaps posing risks for seals and walrus that many Alaska Native villagers depend upon for food.
Glaciers are shrinking, although experts caution that's not entirely due to climate change. Just a few miles from the state Capitol, tourists can compare the Mendenhall Glacier with historical photographs showing the massive river of ice extending hundreds of yards farther into the lake it feeds.
For Alaskans happy enough to avoid those days when vinyl car upholstery shattered in the extreme cold, these changes may not seem such a big deal. But Weller said the consequences of climate change in Alaska can be just as significant as scorched deserts in the agricultural Midwest or rising sea levels flooding the Florida Keys.
Rising water could swamp low-lying villages on the Yukon River delta and even the Prudhoe Bay oil fields within a few decades. Melting permafrost could be a more immediate concern because of the many structures built on the frozen ground.
"While it melts, problems occur," Weller said. "Roads collapse. Houses collapse. Pipelines have to be re-engineered."
Weller said the news isn't all bad. Warmer temperatures and less sea ice could aid oil exploration and ease winter transportation problems. Agriculture could flourish as a longer growing season combines with the near-constant sunlight of Alaska's summer, which already produces gargantuan specimens of some vegetables in the Southcentral part of the state.
But some consequences likely can't be judged. What will warmer weather do to the complex marine ecosystems that nourish Alaska's bountiful fisheries? A longer growing season could spur tree growth in the state's forests, but would that be offset by more severe insect infestations and increased fire danger?
Any answer to those questions would be only speculation, Weller said.
"There's no need to panic," Weller said. "There's a need to look at this intelligently and think what kind of strategies we might want to put into place to meet these challenges, because challenges they will be, and we need to be prepared for them."