By MALCOLM RITTER, AP Science Writer Malcolm Ritter, Ap Science Writer 1 hr
50 mins ago
Beijing had its coldest morning in almost 40 years and its biggest snowfall
since 1951. Britain is suffering through its longest cold snap since 1981. And
freezing weather is gripping the Deep South, including Florida's orange groves
and beaches.
Whatever happened to global warming?
Such weather doesn't seem to fit with warnings from scientists that the Earth
is warming because of greenhouse gases. But experts say the cold snap doesn't
disprove global warming at all it's just a blip in the long-term heating
trend.
"It's part of natural variability," said Gerald Meehl, a senior scientist at
the National Center for Atmospheric Research in Boulder, Colo. With global
warming, he said, "we'll still have record cold temperatures. We'll just have
fewer of them."
Deke Arndt of the National Climatic Data Center in Asheville, N.C., noted that
2009 will rank among the 10 warmest years for Earth since 1880.
Scientists say man-made climate change does have the potential to cause more
frequent and more severe weather extremes, such as heat waves, storms, floods,
droughts and even cold spells. But experts interviewed by The Associated Press
did not connect the current frigid blast to climate change.
So what is going on?
"We basically have seen just a big outbreak of Arctic air" over populated areas
of the Northern Hemisphere, Arndt said. "The Arctic air has really turned
itself loose on us."
In the atmosphere, large rivers of air travel roughly west to east around the
globe between the Arctic and the tropics. This air flow acts like a fence to
keep Arctic air confined.
But recently, this air flow has become bent into a pronounced zigzag pattern,
meandering north and south. If you live in a place where it brings air up from
the south, you get warm weather. In fact, record highs were reported this week
in Washington state and Alaska.
But in the eastern United States, like some other unlucky parts of the globe,
Arctic air is swooping down from the north. And that's how you get a
temperature of 3 degrees in Beijing, a reading of minus-42 in mainland Norway,
and 18 inches of snow in parts of Britain, where a member of Parliament who
said the snow "clearly indicates a cooling trend" was jeered by colleagues.
The zigzag pattern arises naturally from time to time, but it is not clear why
it's so strong right now, said Michelle L'Heureux, a meteorologist at the
Climate Prediction Center of the National Oceanic and Atmospheric
Administration. The center says the pattern should begin to weaken in a week or
two.
Jeff Masters, director of meteorology for Weather Underground, a forecasting
service, said he expects more typical winter weather across North America early
next week.
That will be welcome news in the South, where farmers have been trying to
salvage millions of dollars' worth of strawberries and other crops.
On Miami Beach, tourists bundled up in woolen winter coats and hooded
sweatshirts Wednesday beneath a clear blue sky. Some brazenly let the water
wash over their feet and a few even lay out in bikinis and swimming trunks. A
brisk wind blew and temperatures hovered in the 50s.
"Last year we were swimming every day," said Olivia Ruedinger of Hamburg,
Germany. "I miss that."
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Raphael Satter in London, Cara Anna in Beijing, and Christine Armario in Miami
contributed to this report.