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Committed Warming:
Climate Monitoring and Climate
Forecasts:
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Ocean’s Inertia Delays Warming
by Greenhouse Gases, but Makes it Hard to Reverse Course
Measurements of ocean warming
over the last 10 years now confirm that the Earth is out of energy balance,
said James Hansen, director of NASA’s Goddard Institute for Space Studies.
The Institute’s climate model predicted the same imbalance that is suggested
by ocean observations. This energy imbalance can explain the warming observed
in the 20th century, and also commits the planet to even more
warming in the future resulting from past emissions of greenhouse gases.
Hansen published the assertion on 28 April in Science Express1
online.
“The primary symptom
of Earth’s thermal inertia,” Hansen wrote, “is an imbalance between
the energy absorbed and emitted by the planet.” When these are
in balance, the planet neither warms nor cools.
Hansen calculates
that the surface of Earth is absorbing more energy than it is
releasing back to space as heat. The extra energy is equivalent
to one night-light shining on every square meter of the surface
of Earth. The difference (in Watts) is the energy imbalance of
the planet, which has been growing steadily since about 1960.
Full
story continues inside. . . .
_____________
1. “Earth’s
energy imbalance: confirmation and implications” by James
Hansen and 14 other colleagues (2005). Science express (online),
28 April 2005.
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The Editor is
pleased to acknowledge the assistance of John Cybulski,
Brett Ferber, David Rodenhuis, Lawrence Feinberg, and Mark
Gunzelman for critical reviews of the content of this issue. |
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Pine Marten, resident of Arctic forests
Credit: NOAA Photo Library
Arctic climate
impacts
Sea ice is considered
a “key indicator” of
climate change, as it is very sensitive to temperature changes.
Arctic Ocean ice cover has declined 15 to 20% in area over the
last 30 summers. And where there is ice, it is 10 to 15% thinner
than it used to be. The loss of ice is impacting all wildlife
that live on the ice or at the ice edge, and human societies
whose cultural fabric is interwoven with these creatures of
the North.
See "Impacts
of a Warming Arctic" and other news
of changes in the Arctic and Antarctic.
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