Warming Troposphere Disproves Skeptics' Satellite Argument
Troposphere Is Warming Too, Decades Of Data Show
Planetark.org, Nov. 16, 2010
Not
only is Earth's surface warming, but the troposphere -- the lowest
level of the atmosphere, where weather occurs -- is heating up too, U.S.
and British meteorologists reported on Monday.
In
a review of four decades of data on troposphere temperatures, the
scientists found that warming in this key atmospheric layer was
occurring, just as many researchers expected it would as more greenhouse
gases built up and trapped heat close to the Earth.
This
study aims to put to rest a controversy that began 20 years ago, when a
1990 scientific report based on satellite observations raised questions
about whether the troposphere was warming, even as Earth's surface
temperatures climbed.
The
original discrepancy between what the climate models predicted and what
satellites and weather balloons measured had to do with how the
observations were made, according to Dian Seidel, research meteorologist
for the U.S. National Oceanic and Atmospheric Administration.
It
was relatively easy to track surface temperatures, since most weather
stations sat on or close to the ground, Seidel said by telephone from
NOAA's Air Resources Laboratory in Silver Spring, Maryland, outside
Washington.
Measuring
temperature in the troposphere is more complicated. Starting in the
late 1950s, scientists dangled weather instruments from big balloons,
with the data sent back to researchers by radio transmission as the
balloons rose through the six miles of the troposphere.
BALLOONS AND SATELLITES
The
first satellite data on troposphere temperature was gathered in 1979,
but neither weather balloons nor these early satellite weather
observations were accurate measures of climate change, Seidel said.
"They're
weather balloons and weather satellites, they're not climate balloons
and climate satellites," she said. "They're not calibrated precisely
enough to monitor small changes in climate that we expect to see."
When
the 1990 study was published, showing a lack of warming in the
troposphere especially in the tropics, it prompted some to question the
reality of surface warming and whether climate models could be relied
upon, NOAA said in a statement.
This
latest paper reviewed 195 cited papers, climate model results and
atmospheric data sets, and found no fundamental discrepancy between what
was predicted and what is happening in the troposphere. It is warming,
the study found.
This
study is one of several published this year pushing back against those
who doubt the reality of climate change and the role human activities
play in it.
Scientists
at NOAA, the United Kingdom Met Office and the University of Reading
contributed to the paper, published on Monday in Wiley Interdisciplinary
Reviews - Climate Change, a peer-reviewed journal.
International
climate change talks are set to start on November 29 in Cancun, Mexico,
but prospects for a global deal to curb greenhouse emissions are
considered slim.
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