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SCIENTISTS SAY ARCTIC ONCE WAS TROPICAL
By Seth Borenstein
Associated Press
May 31, 2006
http://news.yahoo.com/s/ap/20060531/ap_on_sc/hot_arctic
WASHINGTON - Scientists have found what might have been the
ideal ancient
vacation hotspot with a 74-degree Fahrenheit average
temperature, alligator
ancestors and palm trees. It's smack in the middle of the
Arctic.
First-of-its-kind core samples dug up from deep beneath the
Arctic Ocean
floor show that 55 million years ago an area near the North Pole
was
practically a subtropical paradise, three new studies show.
The scientists say their findings are a glimpse backward into a
much
warmer-than-thought polar region heated by run-amok greenhouse
gases that
came about naturally.
Skeptics of man-made causes of global warming have nothing to
rejoice over,
however. The researchers say their studies appearing in
Thursday's issue of
Nature also offer a peek at just how bad conditions can get.
"It probably was (a tropical paradise) but the mosquitoes were
probably the
size of your head," said Yale geology professor Mark Pagani, a
study
co-author.
And what a watery, swampy world it must have been.
"Imagine a world where there are dense sequoia trees and cypress
trees like
in Florida that ring the Arctic Ocean," said Pagani, a member of
the
multinational Arctic Coring Expedition that conducted the
research.
Millions of years ago the Earth experienced an extended period
of natural
global warming. But around 55 million years ago there was a
sudden
supercharged spike of carbon dioxide that accelerated the
greenhouse effect.
Scientists already knew this "thermal event" happened but are
not sure what
caused it. Perhaps massive releases of methane from the ocean,
the
continent-sized burning of trees, lots of volcanic eruptions.
Many experts figured that while the rest of the world got really
hot, the
polar regions were still comfortably cooler, maybe about 52
degrees
Fahrenheit.
But the new research found the polar average was closer to 74
degrees. So
instead of Boston-like weather year-round, the Arctic was more
like Miami
North. Way north.
"It's the first time we've looked at the Arctic, and man, it was
a big
surprise to us," said study co-author Kathryn Moran, an
oceanographer at the
University of Rhode Island. "It's a new look to how the Earth
can respond to
these peaks in carbon dioxide."
It's enough to make Santa Claus break into a sweat.
The 74-degree temperature, based on core samples which act as a
climatic
time capsule, was probably the year-round average, but because
data is so
limited it might also be just the summertime average,
researchers said.
What's troubling is that this hints that future projections for
warming,
several degrees over the next century, may be on the low end,
said study
lead author Appy Sluijs of the Institute of Environmental
Biology at Utrecht
University in the Netherlands.
Also it shows that what happened 55 million years ago was proof
that too
much carbon dioxide -- more than four times current levels --
can cause
global warming, said another co-author Henk Brinkhuis at Utrecht
University.
Purdue University atmospheric sciences professor Gabriel Bowen,
who was not
part of the team, praised the work and said it showed that
"there are
tipping points in our (climate) system that can throw us to
these
conditions."
And the new research also gave scientists the idea that a simple
fern may
have helped pull Earth from a hothouse to an icehouse by sucking
up massive
amounts of carbon dioxide. Unfortunately, this natural solution
to global
warming was not exactly quick: It took about a million years.
With all that heat and massive freshwater lakes forming in the
Arctic, a
fern called Azolla started growing and growing. Azolla, still
found in warm
regions today, grew so deep, so wide that eventually it started
sucking up
carbon dioxide, Brinkhuis theorized. And that helped put the
cool back in
the Arctic.
Bowen said he has a hard time accepting that part of the
research, but
Brinkhuis said the studies show tons upon tons of thick mats of
Azolla
covered the Arctic and moved south.
"This could actually contribute to push the world to a cooling
mode,"
Brinkhuis said, but only after it got hotter first and then it
would take at
least 800,000 years to cool back down. It's not something to
look forward
to, he said.
............
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