Sea Ice

The steady melting of Arctic ice greatly accelerated this summer, a warning sign that some scientists worry could mean global warming has passed a tipping point. One even speculated that summer sea ice would be gone in five years. Greenland's ice sheet melted nearly 19 billion tons more than the previous high mark, and the volume of Arctic sea ice at summer's end was half what it had been four years earlier, according to new NASA satellite data obtained by the Associated Press.

SEATTLE -- Polar bears are skating on thin ice in Alaska these days: Warming temperatures have resulted in dramatic shrinkage of sea ice, leaving the bears with fewer ice floes on which to rest and hunt seals. But at least for the moment, the Endangered Species Act won't be used to control the greenhouse gas emissions that conservationists say are contributing to climate change and posing one of the biggest threats to the bears' survival. The Obama administration on Tuesday released a proposed rule that -- like an earlier version put forward under President  George W. Bush -- exempts operations outside the bears' normal territory from restrictions on activities.

Arctic sea ice is melting three times faster than many scientists had projected, U.S. researchers reported just days ahead of the next major international report on climate change. Scientists at the National Center for Atmospheric Research and the University of Colorado in Boulder on Monday said they had concluded, using actual measurements, that Arctic sea ice had declined at an average rate of about 7.8% per decade between 1953 and 2006.

In one of the most dramatic signs ever documented of how shrinking Arctic sea ice impacts polar bears, researchers at the U.S. Geological Survey in Alaska have tracked a female bear that swam nine days across the deep, frigid Beaufort Sea before reaching an ice floe 426 miles offshore. The marathon swim came at a cost: With little food likely available once she arrived, the bear lost 22% of her body weight and her year-old female cub, who set off on the journey but did not survive, the researchers said.

The discovery of a large rookery of emperor penguins in Antarctica has raised hopes that the birds were not disastrously affected by a huge iceberg last year. The appearance in the Ross Sea of an iceberg the size of Jamaica and an increase in sea ice made it almost impossible for the birds to find food, causing the deaths of thousands of penguin chicks. But researchers on a U.S.

Sea ice in the Arctic Ocean has reached its second lowest level in nearly 30 years, according to new satellite measurements released this week. The National Snow and Ice Data Center reported that sea ice in the Arctic now covers about 2.03 million square miles. The lowest point since satellite measurements began in 1979 was 1.65 million square miles set last September. With about three weeks left in the Arctic summer, this year could wind up breaking that record, according to scientists.

Nine polar bears were observed in one day swimming in open ocean off Alaska's northwest coast, an increase from previous surveys that may indicate warming conditions are forcing bears to make riskier long-distance swims to stable sea ice or land. The bears were spotted in the Chukchi Sea on a flight Saturday by a federal marine contractor, Science Applications International Corp. Observers were looking for whales but also recorded walrus and polar bears, said project director Janet Clark.

The sea ice that waxes and wanes with the seasons at the poles has long been seen as a window into the Earth's complex climate system. Any global changes are likely to be most visible--and extreme--on the frozen edges of the Earth that are most vulnerable to warming. But that ice has long frustrated legions of scientists trying to capture its vagaries. Icebreakers moving through the region and taking measurements are rare, and nonexistent in the winter when the pack ice freezes tight.

As federal marine mammal experts in Alaska scramble to study how global warming will affect walrus, polar bears and ice seals, they warn there are limit to the protections they can provide. They can restrict hunters, ship traffic and offshore petroleum activity, but they acknowledge there are limits if the animals' basic habitat -- sea ice -- disappears every summer. "Ultimately it's beyond my scope," said Joel Garlich-Miller, a walrus expert for the U.S. Fish and Wildlife Service in Anchorage.

The historic loss of sea ice seen in the Arctic in recent years is tied to widespread warming in the polar region that is increasing at a rate of more than 2 degrees per decade, according to a NASA satellite study released Thursday. Last year, the summer ice that normally clogs Arctic seas was at historically low levels. This summer, the ice remained at near record lows, and the Arctic's largest ice shelf cracked apart.

A dispute about how much the government should protect polar bears has turned into a battleground for environmentalists and some of the country's most powerful business organizations over the larger question of global warming. On Wednesday, the Interior Department filed arguments in federal court defending its decision to classify polar bears as "threatened" rather than "endangered" despite widespread shrinkage of the sea ice that forms the bears' natural habitat. What makes the issue so sensitive is that, if polar bears received the stricter endangered classification, the Obama administration would be pressured to attack the problem at its source: the petroleum, coal and manufacturing companies that emit the greenhouse gases scientists say are a major factor in climate change.

On a November evening, with the spring sun in northern Antarctica slowly setting about 11 p.m., the view from the top of the Marr Ice Piedmont ? a glacier nearly 40 miles long by 20 miles wide ? was all ice and sky. Through the dust-free atmosphere, I gazed at mountain peaks 120 miles to the south, their summits enveloped in rivers of ice that dropped sharply to the Southern Ocean. The sea itself was frozen, its surface studded with countless icebergs. The scene in front of me, devoid of any sign of man, glowed with a cool, blue purity.

Polar bears are likely to lose out to grizzly bears in fierce competition for food as climate change drives the two species into shared habitat, biologists have concluded. A study released Tuesday was based on 3-D computer modeling that compared the skull and jaw strength of the two bruins and found polar bears ill-suited to the tougher chewing demands posed by the largely vegetarian diet of their grizzly cousins. The study, funded by the National Science Foundation, was conducted by evolutionary biologists at UCLA and published in an online journal of the Public Library of Science.

1 South Africa Tourism officials are warning hotels, airlines and restaurants not to scare off tourists by hiking prices during next summer's FIFA World Cup soccer tournament. With about 500,000 sports fans expected to descend on South Africa and spend an estimated $850 million during the monthlong event, tourism officials said last month that they feared visitors would be put off by exorbitant costs as hotels and guest lodges raise their prices. Media reports have said some hotels plan to charge up to $250 for a basic room that usually costs $100 to $150.

In what would be the largest habitat zone ever established in the U.S. to protect a species from extinction, the federal government today proposed designating 200,541 square miles on the coast of Alaska as critical habitat for polar bears. Officials said the designation is not likely to further slow the pace of oil and gas development, and it crucially would not impose any controls to slow the biggest threat to polar bears, the melting of sea ice as a result of climate change. Those steps are crucial for polar bears but are being addressed separately in Congress through proposals to cap greenhouse gas emissions, said Tom Strickland, assistant Interior secretary for fish, wildlife and parks.

Two German merchant ships have traversed the fabled Northeast Passage after global warming and melting ice opened a route from South Korea along Russia's Arctic coast to Siberia. Now the German-owned ships are poised to complete their journey through the cold waters where icebergs abound, heading for Rotterdam in the Netherlands with 3,500 tons of construction parts. The merchant ships MV Beluga Fraternity and MV Beluga Foresight arrived this week in Yamburg, Siberia, their owner Beluga Shipping GmbH said Friday.

In what would be the largest habitat zone ever established in the U.S. to protect a species from extinction, the federal government today proposed designating 200,541 square miles on the coast of Alaska as critical habitat for polar bears. Officials said the designation is not likely to further slow the pace of oil and gas development, and it crucially would not impose any controls to slow the biggest threat to polar bears, the melting of sea ice as a result of climate change. Those steps are crucial for polar bears but are being addressed separately in Congress through proposals to cap greenhouse gas emissions, said Tom Strickland, assistant Interior secretary for fish, wildlife and parks.

SEATTLE -- Polar bears are skating on thin ice in Alaska these days: Warming temperatures have resulted in dramatic shrinkage of sea ice, leaving the bears with fewer ice floes on which to rest and hunt seals. But at least for the moment, the Endangered Species Act won't be used to control the greenhouse gas emissions that conservationists say are contributing to climate change and posing one of the biggest threats to the bears' survival. The Obama administration on Tuesday released a proposed rule that -- like an earlier version put forward under President  George W. Bush -- exempts operations outside the bears' normal territory from restrictions on activities.

I am beluga bait. Bobbing at the end of a rope tied around my feet, I am being slowly towed in the wake of a Zodiac, a small, inflatable boat, through the icy waters of Hudson Bay. Clad in a partly inflated rubber dry suit, I look like a Michelin Tire Man who has sprouted a snorkel as I peer into the murky brown, tannin-stained cocktail of salt and freshwater. I have come all the way to far northern Manitoba, Canada, to snorkel with beluga whales that, if they do appear out of the gloom, will likely scare the daylights out of me. As my heart races, I remember my guide suggesting I sing to attract these most vocal of whales, known as "canaries of the sea" for their high-pitched songs and rhythmic clicks.

Four miles south of the Arctic Circle, the morning sky is streaked with apricot. Frozen rivers split the tundra of the Seward Peninsula, coiling into vast lakes. And on a silent, wind-whipped pond, a lone figure, sweating and panting, shovels snow off the ice. The young woman with curly reddish hair stops, scribbles data, snaps a photo, grabs a heavy metal pick and stabs at white orbs in the thick black ice.