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Twenty
years ago this month, government and university scientists
ventured to Antarctica to study the cause of a hole in
the stratospheric ozone layer over the southernmost continent.
Those observations were the first definitive demonstration
that humans are capable of affecting the entire global
climate system and led to the Montreal Protocol, the first
treaty to address the Earth's environment.
Today, Susan Solomon and David Hoffman, who led the research
team, met with colleagues from the National Oceanic and
Atmospheric Administration (NOAA) and the National Science
Foundation (NSF) at a news briefing in Washington, D.C.,
to reflect on the importance of the finding and discuss
its implications for the future.
"The patient hasn't recovered," said Hoffman,
who heads NOAA's global atmospheric monitoring program.
"But it's not getting any sicker. We really have
not seen any recovery in Antarctica," he said.
Hoffman also predicted it would take until 2060 for the
ozone layer to heal completely, provided humans stop all
release of man-made substances containing chlorine or
bromine.
Their work began in 1986, when NSF, NOAA and NASA rapidly
put together a research team, known as the National Ozone
Expedition, or NOZE. The purpose was to discover the cause
of a confimed depletion of ozone in the Earth's atmosphere
over Antarctica. In just two months, the team led by Solomon
of NOAA and Hoffman, who was then at the University of
Wyoming, learned most of what we know about the ozone
hole, especially the role chlorofluorocarbons, or CFCs,
in destroying the ozone layer--which protects the Earth
from ultraviolet radiation.
The danger of ozone destruction, they said, is increased
risk of cancers and cataracts, and mutations in wildlife.
Because CFCs are not considered greenhouse gases, like
carbon dioxide, they do not contribute directly to global
warming.
International negotiators meeting in Canada in 1987 produced
the Montreal Protocol, which was ratified by 29 countries
and the EEC in 1989, and called for a phase-out of CFC
production in industrialized countries.
Solomon was later awarded the National Medal of Science
for her work.
NOZE took place during a time when investigating Antarctica
was mostly the work of explorers, said Erick Chiang, who
is in charge of U.S. Antarctic operations, logistics,
telecommunications, science support and construction at
NSF. In the 1980s, dog teams were used for transportation
and communications were sent north by 75 baud teletype
machine. Visitors were required to have their wisdom teeth
removed to prevent dental problems, and power of attorney
was assigned to someone back home--just in case. And no
one had tried to fly in a research expedition in August,
as they did for NOZE.
"Planning for supporting the ozone expedition has
really been a model to support research in Antarctica,"
said Chiang.
Now, Chiang said, infrastructure for scientific research
in Antarctica are state of the art. "We now have
the ability to access the continent and move around on
it like never before," he said. Vast improvements
in technology, transportation and creature comforts are
now able to support the ambitious research themes of the
upcoming International Polar Year (IPY). The White House
Office of Science Technology and Policy has identified
NSF as the lead federal agency for coordinating U.S. IPY
activities.
Extending from March 2007 through March 2009, IPY is
envisioned as an intense scientific campaign to explore
new frontiers in polar science, improve our understanding
of the critical role of the polar regions in global processes,
and educate the public about the polar regions. NSF has
identified climate research as two of its three emphasis
areas for the upcoming International Polar Year (IPY).
The polar ice sheets are dynamic features, for example,
intimately connected with global climate change and sea
level. The West Antarctic Ice Sheet, for instance, shows
signs of instability due to climate change. Warming could
trigger its rapid collapse and possibly raise sea level
worldwide by as much as 20 feet.
In the Arctic, NSF supports Summit Camp, located at the
peak of the Greenland ice sheet. Year-round operations
study air-snow interactions, knowledge of which is crucial
for interpreting data from ice cores drilled in the area
and elsewhere.
During the past few decades, the Arctic has experienced
significant environmental changes that could have broad-reaching
consequences for human populations in the form of long-term
impacts on local ecosystems, as well as on global climate.
These environmental changes are thought to arise from
a complex interplay of physical drivers of oceanic, atmospheric
and terrestrial origin and appear to be correlated with
changes in the Polar Vortex and other related phenomena.
It is not known whether these changes are cyclical, indicating
the system may eventually return to a more familiar state,
or if they represent a trend that indicates the Arctic
may be changing. Similarly, human and natural contributions
to the changes are not fully understood.
In 2005, NOAA also identified Summit as a very good location
for monitoring springtime Arctic ozone depletion within
the stratosphere in the North. Together with NSF, they
launched a balloon campaign went it appeared a substantial
depletion could occur. Fortunately, the vortex became
disturbed before an ozone hole could form in 2005, but
additional measurements were taken in 2006 and are planned
for 2007.
A third research area will look at adaptations to life
in extreme cold and prolonged darkness. Organisms that
are adapted to polar regions often exhibit unique strategies
for survival in environments with extremes of low temperatures
and wide ranges in annual light. Recent climate changes
may expose polar organisms to greater variability in temperature
and light than they have experienced in the past. For
most polar organisms, little is known about the mechanisms
that control their adaptations to environmental change
at the cellular and genetic levels.
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National
Science Foundation -
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