Scientists confirm earth's energy is out of balance

Gretchen Cook-Anderson/Erica Hupp
Headquarters, Washington April 29, 2005
(Phone: 202/358-0836/1237)

RELEASE: 05-111

SCIENTISTS CONFIRM EARTH'S ENERGY IS OUT OF BALANCE

Scientists have concluded more energy is being absorbed from the sun
than is emitted back to space, throwing the Earth's energy "out of balance"
and warming the globe.

Scientists from NASA, Columbia University, New York, and Lawrence Berkeley
National Laboratory, Berkeley, Calif. used satellites, data from buoys and
computer models to study the Earth's oceans. They confirmed the energy
imbalance by using precise measurements of increasing ocean heat content
over the past 10 years.

The study reveals Earth's energy imbalance is large by standards of the
planet's history. The imbalance is 0.85 watts per meter squared. That will
cause an additional warming of 0.6 degrees Celsius (1 degree Fahrenheit) by
the end of this century.

To understand the difference, think of a one-watt light bulb shining over an
area of one square meter (10.76 square feet). Although it doesn't seem like
much, adding up the number of feet around the world creates a big effect. To
put this number into perspective, an imbalance of one-watt per square meter,
maintained for the past 10,000 years is enough to melt ice equivalent to one
kilometer (.6 mile) of sea level, if there were that much ice.

"The energy imbalance is an expected consequence of increasing atmospheric
pollution, especially carbon dioxide, methane, ozone, and black carbon
particles. These pollutants block the Earth's heat radiation from escaping
to space, and they increase absorption of sunlight," said Jim Hansen of
NASA's Goddard Institute for Space Studies, New York. He is the lead author
of the new study, which is in this week's Science Magazine Science Express.

As the Earth warms it emits more heat. Eventually the Earth will be back in
balance, if the greenhouse gas emissions are kept at the same level of
today. Scientists know it takes the ocean longer to warm than the land. The
lag in the ocean's response has practical consequences. It means there is an
additional global warming of about one degree Fahrenheit that is already in
the pipeline. Even if there were no further increase of human-made gases in
the air, climate would continue to warm that much over the next century.

Warmer world-wide water temperatures also affect other things. "Warmer
waters increase the likelihood of accelerated ice sheet disintegration and
sea level rise during this century," Hansen said. Since 1993, sea levels
have been measured by satellite altimeters. Data has shown they have risen
by approximately 3.1 centimeters or 1.26 inches per decade.

Although 3.1 centimeters is a small change, the rate of increase is twice as
large as in the preceding century. There are positive feedbacks that come
into play, as the area of ice melt increases. The researchers agree
monitoring ice sheets and sea level is necessary to best ensure the system
is in balance.

For more information and images about this story on the Internet, visit:

http://www.nasa.gov/vision/earth/env...th_energy.html



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Jacques :-)

www.spacepatches.info