November 27, 2006 — By Beth Duff-Brown, Associated Press
EUREKA, Nunavut Territory — Scientists
are peering into the clouds near the top of the world, trying to solve a
mystery and learn something new about global warming.
The mystery is the droplets of water in the clouds. With the North Pole
just 685 miles away, they should be frozen, yet more of them are liquid
than anyone expected.
So the scientists working out of a converted blue cargo container are
trying to determine whether the clouds are one of the causes -- or effects
-- of Earth's warming atmosphere.
"Much to our surprise, we found that Arctic clouds have got lots of
super-cooled liquid water in them. Liquid water has even been detected in
clouds at temperatures as low as minus 30 degrees Celsius (minus 22 F),"
said Taneil Uttal, chief of the Clouds and Arctic Research Group at the
Earth Systems Research Laboratory of the U.S. National Oceanic and
Atmospheric Administration (NOAA).
"If a cloud is composed of liquid water droplets in the Arctic, instead of
ice crystals, then that changes how they will interact with the earth's
surface and the atmosphere to reflect, absorb and transmit radiation,"
said Uttal.
"It's a new science, driven by the fact that everybody doing climate
predictions says that clouds are perhaps the single greatest unknown
factor in understanding global warming."
With NASA reporting that 2005 was the warmest year on record worldwide,
the debate over global warming marches on, but not here. The American and
Canadian scientists at the Eureka Weather Station in the northern Canadian
territory of Nunavut, like the Inuit who are seeing their native habitat
thaw, are beyond questioning the existence of climate change.
"If we compare the debate over the theory of evolution with the debate
over the theory of global warming -- global warming's a whole lot more
certain at the moment," said Jim Drummond, a University of Toronto physics
professor and chief investigator for the Canadian Network for the
Detection of Atmospheric Change.
"By and large," he said, "we are not now arguing about whether global
warming is going to happen; the argument has turned to: How big is it
going to be?"
Uttal, Drummond and other American and Canadian scientists recently
visited Eureka, an outpost established jointly by Canada and the United
States in 1947 and now equipped with instruments that sound like sci-fi
inventions -- the ozone spectrophotometer, for instance, or the
tropospheric lidar. (A lidar, an amalgamation of "light" and "radar," uses
laser light to detect atmospheric particles.)
The new technology helps to better understand the impact of clouds on
Earth's surface temperature. The clouds being studied here range from six
miles high to almost touching the ground.
"For a couple of decades we have known that super-cooled liquid water
droplets could exist in clouds," Uttal said. "But the prevalence of it in
Arctic clouds was not really known until these specialized sensors
starting operating in the Arctic about eight years ago."
"The really exciting thing," she said, will be the ability to track an
aerosol layer or an Asian dust cloud from their source and measure their
effect on a cloud.
Uttal noted that water clouds are more likely to warm the Arctic
atmosphere than ice clouds, since the liquid clouds retain more heat
radiated by the Earth's surface. "This means that the ice-to-water ratios
in clouds may be very important in controlling the Arctic surface
temperatures and how it melts," she said.
In Nunavut, the melting is keenly felt. "In the old days, we used to have
10 months of winter; now it's six," said Simon Awa, an Inuit leader and
deputy minister for the environment of Nunavut who was on the trip to
Eureka. "Every year we're getting winter later and later."
For these 155,000 people of Canada, Greenland, Russia and the United
States, it means less time to hunt caribou, walrus and polar bear. Studies
show that average winter temperatures have increased as much as 7 degrees
in the Arctic over the last 50 years. The permafrost -- ground that is
continually frozen for at least two years -- is thawing, imperiling polar
bears and forcing other animals to migrate farther north.
The walrus have moved farther away, said Awa. "So you're taking more time
out, away on the land hunting." Meanwhile, families back home are forced
to eat store-bought food that is costlier and less healthy.
"The majority of the world's population hasn't really felt the global
warming," said Awa. "But right now in the Arctic and in Nunavut, we're
really worried because it's already affecting us. We are a thermometer of
the world for what could happen."
Russ Schnell, director of Observatory and Global Network Operations for
NOAA, notes that climate change is cyclical -- that the planet's
vegetation, over millions of years, sucks in and spits out carbon dioxide.
"All the carbon dioxide in the coal and oil was once in the air. The
plants took it and it went into the oceans or into the ground -- and now
we're taking it back out," says Schnell.
"The cycle is the same today, only you're taking something that took
100,000 years and doing it in one hundred years," he said. "There's a
point where animals can't change fast enough, there's a point where plants
can't change fast enough, so they'll either compete it out or go extinct."