Climate change warms Arctic, cools Antarctica

By Deborah Zabarenko, Environment Correspondent

WASHINGTON (Reuters) - The Arctic and Antarctica are poles apart when it comes to the effects of human-fueled climate change, scientists said on Friday: in the north, it is melting sea ice, but in the south, it powers winds that chill things down.

The North and South poles are both subject to solar radiation and rising levels of climate-warming greenhouse gases, the researchers said in a telephone briefing. But Antarctica is also affected by an ozone hole hovering high above it during the austral summer.

"All the evidence points toward human-made effects playing a major role in the changes that we see at both poles and evidence that contradicts this is very hard to find," said Jennifer Francis, an atmospheric scientist at Rutgers University in New Jersey.

An examination of many previous studies about polar climate, to be published May 6 in the journal Eos, "further depletes the arsenal of those who insist that human-caused climate change is nothing to worry about," Francis said in a telephone briefing.

In the Arctic, Francis and co-authors of the research said, warming spurred by human-generated carbon dioxide emissions has combined with natural climate variations to create a "perfect Arctic storm" that caused a dramatic disappearance of sea ice last year, a trend likely to continue.

'NEW STATE'

"Natural climate variability and global warming were actually working together and they've sent the Arctic into a new state for the climate that has much less sea ice," said James Overland, an oceanographer at the U.S. National Oceanic and Atmospheric Administration. "There's very little chance for the climate to return to the conditions of 20 years ago."

In Antarctica, the ozone hole adds a new factor to an already complicated set of weather patterns, according to Gareth Marshall of the British Antarctic Survey.