A new study is raising more concerns about global warming in the Canadian Arctic and the potentially catastrophic effects on wildlife.

According to new data from U.S. scientists, the coverage of sea ice in the Arctic has declined for a fourth consecutive year, indicating an alarming long-term trend.

The amount of sea ice in 2005 up to September -- the month when it typically reaches its minimum -- is anticipated to be the lowest in a century.

"Having four years in a row with such low ice extents has never been seen before in the satellite record. It clearly indicates a downward trend, not just a short-term anomaly," said Walt Meier of the National Snow and Ice Data Center (NSIDC).

Scientists from NSIDC and NASA tracked the ice melt using satellite images.

The data show that on Sept. 21, 2005, the area covered by ice shrank to 5.32 million square kilometres, the lowest recorded since 1978, when satellite records became available.

"In 2005, it's the lowest on the record. We've watched that retreat from year after year," Environment Canada climatologist Tom Agnew told CTV News in Toronto.

Scientists estimate that the current rate of decline in end-of-summer Arctic ice is now approximately eight per cent per decade.

If the current rates of decline continue, the Arctic in the summertime could be completely ice-free well before the end of this century, researchers say.

There is also evidence that the ice is not building back up in the winter, leaving it even more susceptible to warmer summer temperatures.

"We're concerned that it's not going to recover, that the sea ice will eventually disappear within the next fifty to a hundred years," said Agnew.

As well, the springtime melt is beginning much earlier in areas north of Alaska and Siberia. The 2005 melt season occurred about 17 days earlier than the average time.

Combining with these factors are rising Arctic temperatures. Between January and August 2005, the temperature was two to three degrees Celsius warmer than average across most of the Arctic Ocean when compared to the past 50 years.

One area where this warming impact is being felt is the Northwest Passage through the Canadian Arctic.

This summer, the passage, north of the Siberia coast, was completely ice-free between Aug. 15 and Sept. 28. In earlier centuries, many people died trying to navigate the Northwest Passage, battling bitter cold and thick ice.

Dire predictions

Scientists say the most recent estimates suggest that the last time there was an ice-free Arctic was millions of years ago.

Since then, the vast ice fields have always cooled the summer winds that sweep across them on their way south.

But with studies showing increasing hurricane intensity over the past 30 years linked to rising sea temperatures, and recent record heat waves in North America, a growing number of scientists say it's all interconnected.

Inuit living at the ocean's edge in the Arctic are seeing their bays -- once choaked with ice -- are now empty. Waves now lap the shoreline, as the permafrost softens and hunting on ice floes is becoming increasingly difficult, if at all possible.

Polar bears, dependent on the ice pack to reach their prey, are becoming thin, and birds normally confined to spots further south are now at home in the north.

"Now we're seeing the web of life kind of falling apart before our eyes," said Julia Langer of the World Wildlife Fund. "So we see how important the climate ... the stability of climate is to the stability of eco-systems."

It's a threat that's being felt as far away as Parliament Hill in Ottawa, where politicians face a growing body of scientific evidence suggesting that this is not simply nature taking its course.

"Canada must be a leader of climate change," said Environment Minister Stephan Dion. "It's important for us, for our north, for our role in the world."

Dion plans to push the climate agenda at the international climate conference in Montreal beginning Nov. 28.

In the U.S., meanwhile, Inuit hunters who are threatened by the melting of the Arctic plan to file a petition in December. They're accusing the U.S. of violating their human rights by fueling global warming.

President George Bush's administration has opted out of the Kyoto Treaty to reduce greenhouse gas emissions.

With a report by CTV's Todd Battis in Vancouver

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