Newsgroup: it.politica.internazionale
Titolo: Global Warming Study Predicts Wild Ride

Published on Saturday, October 21, 2006 by the Associated Press
Global Warming Study Predicts Wild Ride
by Seth Borenstein
 
WASHINGTON - The world - especially the Western United States, the
Mediterranean region and Brazil - will likely suffer more extended
droughts, heavy rainfalls and longer heat waves over the next century
because of global warming, a new study forecasts.
A man walks with a dog along a dry cracked reservoir bed in Alcora,
eastern Spain in this 2005 file photo. The world - especially the
Western United States, the Mediterranean region and Brazil - will
likely suffer more extended droughts, heavy rainfalls and longer heat
waves over the next century because of global warming, a new study
forecasts. (AP Photo/Fernando Bustamante)
But the prediction of a future of nasty extreme weather also includes
fewer freezes and a longer growing season.
In a preview of a major international multiyear report on climate
change that comes out next year, a study out of the National Center
for Atmospheric Research details what nine of the world's top computer
models predict for the lurching of climate at its most extreme.
"It's going to be a wild ride, especially for specific regions," said
study lead author Claudia Tebaldi, a scientist at the federally funded
academic research center.
Tebaldi pointed to the Western U.S., Mediterranean nations and Brazil
as "hot spots" that will get extremes at their worst, according to the
computer models.
And some places, such as the Pacific Northwest, are predicted to get a
strange double whammy of longer dry spells punctuated by heavier
rainfall.
As the world warms, there will be more rain likely in the tropical
Pacific Ocean, and that will change the air flow for certain areas,
much like El Nino weather oscillations now do, said study co-author
Gerald Meehl, a top computer modeler at the research center. Those
changes will affect the U.S. West, Australia and Brazil, even though
it's on South America's eastern coast.
For the Mediterranean, the issue has more to do with rainfall in the
tropical Atlantic Ocean changing air currents, he said.
"Extreme events are the kinds of things that have the biggest impacts,
not only on humans, but on mammals and ecosystems," Meehl said. The
study, to be published in the December issue of the peer-reviewed
journal Climatic Change, "gives us stronger and more compelling
evidence that these changes in extremes are more likely."
The researchers took 10 international agreed-upon indices that measure
climate extremes - five that deal with temperature and five with
precipitation - and ran computer models for the world through the year
2099. What Tebaldi called the scariest results had to do with heat
waves and warm nights. Everything about heat waves - their intensity,
length and occurrence - worsens.
"The changes are very significant there," Tebaldi said. "It's enough
to say we're in for a bad future."
The measurement of warm nights saw the biggest forecast changes. Every
part of the globe is predicted to experience a tremendous increase in
the number of nights during which the low temperature is extremely
high. Those warm night temperatures that should happen only once every
decade will likely occur at least every other year by the time we
reach 2099, if not more frequently, Tebaldi said.
Warm nights are crucial because Chicago's 1995 heat wave demonstrated
that after three straight hot nights, people start dying, Meehl said.
However, heat wave deaths are decreasing in the United States because
society has learned to adapt better, using air conditioning, noted
University of Alabama at Huntsville atmospheric sciences professor
John Christy. He is one of a minority of climate scientists who
downplay the seriousness of global warming.
Similarly, the days when the temperature drops below freezing will
plummet worldwide. That's not necessarily a good thing, because fewer
frost days will likely bring dramatic change in wildlife, especially
bug infestation, Tebaldi said.
"It's a disruption of the equilibrium that's been going for many
centuries," Tebaldi said. But she noted that a lengthier growing
season in general is good.
"This notion of the greening of the planet ... generally is a positive
benefit," Christy said.
Christy, who did not participate in the study but acknowledges that
global warming is real and man-made, said an increase in nighttime low
temperatures makes much more sense than the rain-and-drought forecasts
of the paper.
One of the larger changes in precipitation predicted is in the
intensity of rain and snowfall. That means, Tebaldi said, "when it
rains, it rains more" even if it doesn't rain as often.
Tebaldi's assessment jibes with the National Climatic Data Center's
tracking of extreme events in the United States, said David
Easterling, chief of the center's scientific services. Easterling's
group has created a massive climate extreme index that measures the
weather in America. Last year, the United States experienced the
second most extreme year in 95 years; the worst year was in 1998.
On the Net
"Going to the Extremes" study:
http://www.cgd.ucar.edu/ccr/publications/klu-multimodel-extremes-revised.pdf
U.S. government's climate extreme index:
http://www.ncdc.noaa.gov/oa/climate/research/cei/cei.html
© Copyright 2006 The Associated Press

 by Seth Borenstein
Dobbiamo avere fede, non dobbiamo ma dubitare che Egli ci salverà dalla catastrofe.
Lui, il dio Mercato, saprà trovare la soluzione, saprà fare ciò che è giusto, 
perché Egli ci ama: siamo il suo popolo di consumatori, e non vorrebbe mai 
abbandonarci.

 abbandonarci.
Mercato u akbar!