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Science Forum Index » Environment Forum » Climatologists Admit That They're Clueless
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| Reggie |
 Posted: Wed Apr 30, 2008 7:56 pm |
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Guest
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Lots of climate-change studies, still few certainties
The Arctic can be frustrating for scientists trying to predict global
warming.
By Robert c. CowEn
Science columnist Robert Cowen discusses an integrated investigation
of the effects of climate change in the Arctic.
The Arctic can be frustrating for scientists trying to predict climate
change. They know Arctic climate is changing faster than expected. Yet
they don't understand what's happening today well enough to trust
computer projections of what may happen there tomorrow. Two weeks ago,
Nature published a review of this challenge, featuring Greenland's
situation. It concluded that lack of a full-court press to understand
what's happening in the Arctic today "could turn out to be one of the
most short-sighted allocations of [climate research] resources."
Actually, a lot of Arctic research is going on. Halfway through the
International Polar "Year" (March 2007 to March 2009), about 60
countries are involved with about 160 projects. Such efforts are
rapidly building a patchwork of new knowledge. Yet, as Nature points
out, they aren't a "systematic" learning process. Scientists can't
build computer-based climate models on disparate research that turns
up something "totally different" every research season.
The situation in Greenland illustrates this point. Scientists know
that the ice flow from Greenland into the sea is speeding up. They
have suspected that summer meltwater is draining down beneath the ice
and lubricating its flow – therefore accelerating it further.
Some wondered if it could penetrate thousands of feet of rock-hard
ice. Research reported two weeks ago online in Science Express
supplied the answer. Sarah Das at the Woods Hole Oceanographic
Institution, Ian Joughin at the University of Washington, and their
colleagues describe how, in 2006, a 2.2-square-mile lake with 11.6
billion gallons of water drained away in 24 hours. Most of it went in
90 minutes. Dr. Das calls this "clear evidence" that summer meltwater
pools "can actually drive a crack through the ice sheet" all the way
to the bottom. Once there, it can speed up glacial flow by 50 to 100
percent in some broad areas of the ice sheet.
That's an important discovery. But outflow glaciers on the coast that
channel glacial ice to the sea hardly sped up at all in 2006.
Something else seems to be at work.
Scientists' knowledge of ice-flow mechanisms remains too patchy for
prime-time climate forecasting.
So, too, is their knowledge of the continuing loss of Arctic Ocean ice
cover. Last week, Jennifer Kay at the National Center for Atmospheric
Research in Boulder and colleagues explained in Geophysical Research
Letters that summer cloud cover has become an important factor in that
loss. Cloud cover didn't matter that much in the past when the ocean
was largely ice covered. The ice reflected much of the sunlight back
to space.
But now there's more exposed water to soak up sunshine. The warmer
water melts ice from below, thinning it out. Dr. Kay says that "a
single unusually clear summer can now have a dramatic impact." This is
one more factor to add to the changes in winds and currents that
affect sea ice, the relative importance of which is still unknown.
As Nature said two weeks ago, it will take a systemic well-funded
effort by "the entire polar research community" to turn the present
patchwork of programs into a pursuit for useful understanding. |
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| V-for-Vendicar |
| Posted: Wed Apr 30, 2008 10:30 pm |
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Guest
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"Reggie" <Liberal'sWorstNightmare@home.org> wrote
Quote: Lots of climate-change studies, still few certainties
The Arctic can be frustrating for scientists trying to predict global
warming.
By Robert c. CowEn
Science columnist Robert Cowen discusses an integrated investigation
of the effects of climate change in the Arctic.
The Arctic can be frustrating for scientists trying to predict climate
change. They know Arctic climate is changing faster than expected. Yet
they don't understand what's happening today well enough to trust
computer projections of what may happen there tomorrow. Two weeks ago,
Nature published a review of this challenge, featuring Greenland's
situation. It concluded that lack of a full-court press to understand
what's happening in the Arctic today "could turn out to be one of the
most short-sighted allocations of [climate research] resources."
Actually, a lot of Arctic research is going on. Halfway through the
International Polar "Year" (March 2007 to March 2009), about 60
countries are involved with about 160 projects. Such efforts are
rapidly building a patchwork of new knowledge. Yet, as Nature points
out, they aren't a "systematic" learning process. Scientists can't
build computer-based climate models on disparate research that turns
up something "totally different" every research season.
The situation in Greenland illustrates this point. Scientists know
that the ice flow from Greenland into the sea is speeding up. They
have suspected that summer meltwater is draining down beneath the ice
and lubricating its flow - therefore accelerating it further.
Some wondered if it could penetrate thousands of feet of rock-hard
ice. Research reported two weeks ago online in Science Express
supplied the answer. Sarah Das at the Woods Hole Oceanographic
Institution, Ian Joughin at the University of Washington, and their
colleagues describe how, in 2006, a 2.2-square-mile lake with 11.6
billion gallons of water drained away in 24 hours. Most of it went in
90 minutes. Dr. Das calls this "clear evidence" that summer meltwater
pools "can actually drive a crack through the ice sheet" all the way
to the bottom. Once there, it can speed up glacial flow by 50 to 100
percent in some broad areas of the ice sheet.
That's an important discovery. But outflow glaciers on the coast that
channel glacial ice to the sea hardly sped up at all in 2006.
Something else seems to be at work.
Scientists' knowledge of ice-flow mechanisms remains too patchy for
prime-time climate forecasting.
So, too, is their knowledge of the continuing loss of Arctic Ocean ice
cover. Last week, Jennifer Kay at the National Center for Atmospheric
Research in Boulder and colleagues explained in Geophysical Research
Letters that summer cloud cover has become an important factor in that
loss. Cloud cover didn't matter that much in the past when the ocean
was largely ice covered. The ice reflected much of the sunlight back
to space.
But now there's more exposed water to soak up sunshine. The warmer
water melts ice from below, thinning it out. Dr. Kay says that "a
single unusually clear summer can now have a dramatic impact." This is
one more factor to add to the changes in winds and currents that
affect sea ice, the relative importance of which is still unknown.
As Nature said two weeks ago, it will take a systemic well-funded
effort by "the entire polar research community" to turn the present
patchwork of programs into a pursuit for useful understanding.
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| V-for-Vendicar |
| Posted: Wed Apr 30, 2008 10:31 pm |
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Guest
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"Reggie" <Liberal'sWorstNightmare@home.org> wrote
Quote: Lots of climate-change studies, still few certainties
The Arctic can be frustrating for scientists trying to predict global
warming.
By Robert c. CowEn
There is one certainty. Global temperatures are rising rapidly and CO2 is
the cause. |
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| Frank Arthur |
| Posted: Thu May 01, 2008 7:53 am |
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"Reggie" <Liberal'sWorstNightmare@home.org>
The Greenland ice sheet shrank by 50 cubic miles last year. Were it to
melt completely, sea levels would rise 20 feet-which would leave large
areas of Washington, D.C., including the Mall, between the Lincoln
Memorial and the Washington Monument, underwater.
While Washington Slept
The Queen of England is afraid. International C.E.O.'s are nervous.
And the scientific establishment is loud and clear. If global warming
isn't halted, devastating sea-level rises will be inevitable by 2100.
So how did this virtual certainty get labeled a "liberal hoax" in the
U.S.? Try the same tactics Big Tobacco used to deny the dangers of
smoking.
by Mark Hertsgaard May 2006
Ten months before Hurricane Katrina left much of New Orleans
underwater, Queen Elizabeth II had a private conversation with Prime
Minister Tony Blair about George W. Bush. The Queen's tradition of
meeting once a week with Britain's elected head of government to
discuss matters of state-usually on Tuesday evenings in Buckingham
Palace and always alone, to ensure maximum confidentiality-goes back
to 1952, the year she ascended the throne. In all that time, the
contents of those chats rarely if ever leaked.
So it was extraordinary when London's Observer reported, on October
31, 2004, that the Queen had "made a rare intervention in world
politics" by telling Blair of "her grave concerns over the White
House's stance on global warming." The Observer did not name its
sources, but one of them subsequently spoke to Vanity Fair.
"The Queen first of all made it clear that Buckingham Palace would be
happy to help raise awareness about the climate problem," says the
source, a high-level environmental expert who was briefed about the
conversation. "[She was] definitely concerned about the American
position and hoped the prime minister could help change [it]."
Press aides for both the Queen and the prime minister declined to
comment on the meeting, as is their habit. But days after the Observer
story appeared, the Queen indeed raised awareness by presiding over
the opening of a British-German conference on climate change, in
Berlin. "I might just point out, that's a pretty unusual thing for her
to do," says Sir David King, Britain's chief scientific adviser. "She
doesn't take part in anything that would be overtly political." King,
who has briefed the Queen on climate change, would not comment on the
Observer report except to say, "If it were true, it wouldn't surprise
me."
With spring arriving in England three weeks earlier than it did 50
years ago, the Queen could now see signs of climate change with her
own eyes. Sandringham, her country estate north of London, overlooks
Britain's premier bird-watching spot: the vast North Sea wetlands
known as the Wash. A lifelong outdoorswoman, the Queen had doubtless
observed the V-shaped flocks of pink-footed geese that descend on the
Wash every winter. But in recent years, says Mark Avery, conservation
director of the Royal Society for the Protection of Birds, she also
would have seen a species new to the area: little egrets. These shiny
white birds are native to Southern Europe, Avery says, "but in the
last 5 to 10 years they have spread very rapidly to Northern Europe.
We can't prove this is because of rising temperatures, but it sure
looks like it."
Temperatures are rising, the Queen learned from King and other
scientists, because greenhouse gases are trapping heat in the
atmosphere. Carbon dioxide, the most prevalent of such gases, is
released whenever fossil fuels are burned or forests catch fire.
Global warming, the scientists explained, threatens to raise sea
levels as much as three feet by the end of the 21st century, thanks to
melting glaciers and swollen oceans. (Water expands when heated.)
Unless greenhouse-gas emissions are curbed, warns James Hansen of
NASA, global temperatures could climb 2 to 3 degrees Celsius by 2100.
Such a rise would leave little of Manhattan but the skyscrapers.
This would leave much of eastern England, including areas near
Sandringham, underwater. Global warming would also bring more heat
waves like the one in the summer of 2003 that killed 31,000 people
across Europe. It might even shut down the Gulf Stream, the flow of
warm water from the Gulf of Mexico that gives Europe its mild climate.
If the Gulf Stream were to halt-and it has already slowed 30 percent
since 1992-Europe's temperatures would plunge, agriculture would
collapse, London would no longer feel like New York but like
Anchorage.
The Queen, says King, "got it" on climate change, and she wasn't
alone. "Everyone in this country, from the political parties to the
scientific establishment, to the Archbishop of Canterbury, to our oil
companies and the larger business community, has come to a popular
consensus about climate change-a sense of alarm and a conviction that
action is needed now, not in the future," says Tony Juniper, executive
director of the British arm of the environmental group Friends of the
Earth.
At the time of his meeting with the Queen, Blair was being attacked on
climate change from all ideological sides, with even the Conservatives
charging that he was not doing enough. Yet Blair's statements on the
issue went far beyond those of most world leaders. He had called the
Kyoto Protocol, which has been ratified by 162 countries and requires
industrial nations to reduce greenhouse-gas emissions 5 percent below
1990 levels, "not radical enough." The world's climate scientists,
Blair pointed out, had estimated that 60 percent cuts in emissions
were needed, and he committed Britain to reaching that goal by 2050.
But it wouldn't matter how much Britain cut its greenhouse-gas
emissions if other nations didn't do the same. The U.S. was key, not
only because it was the world's largest emitter but because its
refusal to reduce emissions led China, India, Brazil, and other large
developing countries to ask why they should do so. All this Blair had
also said publicly. In 2001 he criticized the Bush administration for
withdrawing from the Kyoto Protocol. In 2004 he said it was essential
to bring the U.S. into the global effort against climate change,
despite its opposition to Kyoto. |
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