Wednesday May 2, 2:52 AM     Reuters
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Arctic ice cap melting 30 years ahead of forecast*

By Deborah Zabarenko, Environment Correspondent

WASHINGTON (Reuters) - The Arctic ice cap is melting much faster than
expected and is now about 30 years ahead of predictions made by the
Intergovernmental Panel on Climate Change, a U.S. ice expert said on
Tuesday.

This means the ocean at the top of the world could be free or nearly
free of summer ice by 2020, three decades sooner than the global panel's
gloomiest forecast of 2050.

No ice on the Arctic Ocean during summer would be a major spur to global
warming, said Ted Scambos, a glaciologist at the National Snow and Ice
Center in Colorado.

"Right now ... the Arctic helps keep the Earth cool," Scambos said in a
telephone interview. "Without that Arctic ice, or with much less of it,
the Earth will warm much faster."

That is because the ice reflects light and heat; when it is gone, the
much darker land or sea will absorb more light and heat, making it more
difficult for the planet to cool down, even in winter, he said.

Scambos and co-authors of the study, published in the journal
Geophysical Research Letters, used satellite data and visual
confirmation of Arctic ice to reach their conclusions, a far different
picture than that obtained from computer models used by the scientists
of the intergovernmental panel.

"The IPCC report was very careful, very thorough and cautious, so they
erred on the side of what would certainly occur as opposed to what might
occur," Scambos said in a telephone interview.

ICE-FREE SUMMER

The wide possibility of what might occur included a much later melt up
north, or a much earlier one, Scambos said.

"It appears we're on pace about 30 years earlier than expected to reach
a state where we don't have sea ice or at least not very much in late
summer in the Arctic Ocean," he said.

He discounted the notion that the sharp warming trend in the Arctic
might be due to natural climate cycles. "There aren't many periods in
history that are this dramatic in terms of natural variability," Scambos
said.

He said he had no doubt that this was caused in large part by greenhouse
gases in the atmosphere, which he said was the only thing capable of
changing Earth on such a large scale over so many latitudes.

Asked what could fix the problem -- the topic of a new report by the
intergovernmental panel to be released on Friday in Bangkok -- Scambos
said a large volcanic eruption might hold Arctic ice melting at bay for
a few years.

But he saw a continued warm-up as inevitable in the coming decades.

"Long-term and for the next 50 years, I think even the new report will
agree that we're in for quite a bit of warming," Scambos said.

"We just barely now, I think, have enough time and enough collective
will to be able to get through this century in good shape, but it means
we have to start acting now and in a big way."