Interesting New Climate Research From UAH

We received this news release from our friends at UAH… I get the idea you won’t hear this on any mainstream media outlet (journalists, actors, and politicians are the primary drivers behind the catastrophic, man-made global warming movement), but you can read the whole release here:

For additional information:
Dr. Roy Spencer, 256.961.7960 or 256.652.5974
Phillip Gentry, 256.824.6420

For immediate release

Cirrus disappearance: Warming might thin heat-trapping clouds

HUNTSVILLE, Ala. (Aug. 9, 2007) – The widely accepted (albeit unproven)
theory that manmade global warming will accelerate itself by creating more
heat-trapping clouds is challenged this month in new research from The
University of Alabama in Huntsville.

Instead of creating more clouds, individual tropical warming cycles that
served as proxies for global warming saw a decrease in the coverage of
heat-trapping cirrus clouds, says Dr. Roy Spencer, a principal research
scientist in UAHuntsville’s Earth System Science Center.

That was not what he expected to find.

“All leading climate models forecast that as the atmosphere warms there
should be an increase in high altitude cirrus clouds, which would amplify
any warming caused by manmade greenhouse gases,” he said. “That
amplification is a positive feedback. What we found in month-to-month
fluctuations of the tropical climate system was a strongly negative
feedback. As the tropical atmosphere warms, cirrus clouds decrease. That
allows more infrared heat to escape from the atmosphere to outer space.”

The results of this research were published today in Geophysical Research
Letters, a journal of the American Geophysical Union. The paper was
co-authored by UAHuntsville’s Dr. John R. Christy and Dr. W. Danny Braswell,
and Dr. Justin Hnilo of Lawrence Livermore National Laboratory, Livermore,
CA.

“While low clouds have a predominantly cooling effect due to their shading
of sunlight, most cirrus clouds have a net warming effect on the Earth,”
Spencer said. With high altitude ice clouds their infrared heat trapping
exceeds their solar shading effect.

In the tropics most cirrus-type clouds flow out of the upper reaches of
thunderstorm clouds. As the Earth’s surface warms – due to either manmade
greenhouse gases or natural fluctuations in the climate system – more water
evaporates from the surface. Since more evaporation leads to more
precipitation, most climate researchers expected increased cirrus cloudiness
to follow warming.

“To give an idea of how strong this enhanced cooling mechanism is, if it was
operating on global warming, it would reduce estimates of future warming by
over 75 percent,” Spencer said. “The big question that no one can answer
right now is whether this enhanced cooling mechanism applies to global
warming.”

The only way to see how these new findings impact global warming forecasts
is to include them in computerized climate models.

“The role of clouds in global warming is widely agreed to be pretty
uncertain,” Spencer said. “Right now, all climate models predict that clouds
will amplify warming. I’m betting that if the climate models’ ‘clouds’ were
made to behave the way we see these clouds behave in nature, it would
substantially reduce the amount of climate change the models predict for the
coming decades.”

The UAHuntsville research team used 30- to 60-day tropical temperature
fluctuations – known as “intraseasonal oscillations” – as proxies for global
warming.

“Fifteen years ago, when we first started monitoring global temperatures
with satellites, we noticed these big temperature fluctuations in the
tropics,” Spencer said. “What amounts to a decade of global warming
routinely occurs in just a few weeks in the tropical atmosphere. Then, as if
by flipping a switch, the rapid warming is replaced by strong cooling. It
now looks like the change in cirrus cloud coverage is the major reason for
this switch from warming to cooling.”

The team analyzed six years of data from four instruments aboard three NASA
and NOAA satellites. The researchers tracked precipitation amounts, air and
sea surface temperatures, high and low altitude cloud cover, reflected
sunlight, and infrared energy escaping out to space.

When they tracked the daily evolution of a composite of fifteen of the
strongest intraseasonal oscillations they found that although rainfall and
air temperatures would be rising, the amount of infrared energy being
trapped by the cloudy areas would start to decrease rapidly as the air
warmed. This unexpected behavior was traced to the decrease in cirrus cloud
cover.

The new results raise questions about some current theories regarding
precipitation, clouds and the efficiency with which weather systems convert
water vapor into rainfall. These are significant issues in the global
warming debate.

“Global warming theory says warming will generally be accompanied by more
rainfall,” Spencer said. “Everyone just assumed that more rainfall means
more high altitude clouds. That would be your first guess and, since we
didn’t have any data to suggest otherwise …”

There are significant gaps in the scientific understanding of precipitation
systems and their interactions with the climate, he said. “At least 80
percent of the Earth’s natural greenhouse effect is due to water vapor and
clouds, and those are largely under the control of precipitation systems.

“Until we understand how precipitation systems change with warming, I don’t
believe we can know how much of our current warming is manmade. Without that
knowledge, we can’t predict future climate change with any degree of
certainty.”

Spencer and his colleagues expect these new findings to be controversial.

“I know some climate modelers will say that these results are interesting
but that they probably don’t apply to long-term global warming,” he said.
“But this represents a fundamental natural cooling process in the
atmosphere. Let’s see if climate models can get this part right before we
rely on their long term projections.”

Category: Pre-November 2010 Posts