Two nights after NBC blamed hot summer temperatures on global warming, and on the very day a new scientific report cast doubt on a key assumption behind global warming forecasts, CBS on Thursday evening held global warming culpable for “oppressive August heat” that killed a man in East St. Louis. For an expert assessment, CBS reporter Kelly Cobiella turned only to the Weather Channel climatologist who last year suggested the American Meteorological Society should withhold credentials from any member who dares doubt the man-made global warming mantra: “Dr. Heidi Cullen is a climatologist for the Weather Channel, and sees a definite connection to global warming.” Cullen maintained: “The heat wave that we're seeing now is completely consistent with what we expect in a warmer world because all of our models show us that heat waves will become intense, more frequent, and they'll last longer.”

The CBS Evening News skipped, as Rush Limbuagh predicted the media would, a new study in which, as outlined in a press release, “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.” The posting on the university's site summarized the study published in a scientific journal: “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.”

In highlighting the university's findings on Thursday, Limbaugh noted on his radio show that Spencer had received “no inquiries from the Drive-By Media” and predicted: “There probably won't be.” CBS has provided early confirmation.

On Tuesday's NBC Nightly News, as recounted in my NewsBusters item, Anne Thompson asserted that “global land surface temperatures in January and April were likely the warmest since records began 120 years ago, extremes scientists say are consistent with an increase in carbon dioxide, man-made global warming.”

On her blog back in December, Heidi Cullen created a bit of controversy when she suggested those who don't agree with her on the cause and likely acceleration of global warming should be discredited:

“If a meteorologist can't speak to the fundamental science of climate change, then maybe the AMS shouldn't give them a Seal of Approval.”

For more, check Marc Morano's January post, “The Weather Channel Climate Expert Refuses to Retract Call for Decertification for Global Warming Skeptics,” on the Senate Environment and Public Works Committee's “Inhofe Press Blog.”

In May, Morano posted “Climate Momentum Shifting: Prominent Scientists Reverse Belief in Man-Made Global Warming -- Now Skeptics; Growing Number of Scientists Convert to Skeptics After Reviewing New Research.”

An excerpt from, “Cirrus disappearance: Warming might thin heat-trapping clouds,” a summary posted August 9 on the University of Alabama at Huntsville's Web site:

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 the American Geophysical Union's "Geophysical Research Letters" on-line edition. 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....

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."...

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..."

"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."

The MRC's Brad Wilmouth corrected the closed-captioning against the video to provide this transcript of the August 9 CBS Evening News story:

KATIE COURIC: A layer of heat and moisture is hanging like a wet blanket over the Midwest and South. Heat advisories are up throughout those regions for what can be very dangerous conditions. We have two reports tonight, beginning with Kelly Cobiella.

KELLY COBIELLA: For the fifth straight day, Americans from Orlando to Indianapolis wilted under an oppressive August heat. Hundreds have been treated for heat-related illnesses since the weekend. In St. Louis, people are being urged to spend the day in shelters, a warning that came too late for 87-year-old James Irby, who died in his home [actually in East St. Louis, Illinois]. He didn't have air conditioning.

ALVIN PARKS, Mayor of St. Louis: When I got the news, it just hit me like somebody kicking me in the stomach. I just can't stand the fact that someone might have been saved.

COBIELLA: In Georgia and Alabama, where the heat index has been in the 110's, they've also recorded the highest demand for power in each state's history. Metro trains in Washington, D.C., were slowed from 59 to 45 miles an hour because of worries the steel tracks would bend in the heat. And just west of Memphis, hundreds of dead fish have washed ashore, killed off by a lack of oxygen in overheated lakes.

HEIDI CULLEN, The Weather Channel: There's a poker analogy that global warming stacks the deck for more extreme events.

COBIELLA: Dr. Heidi Cullen is a climatologist for the Weather Channel, and sees a definite connection to global warming.

CULLEN: The heat wave that we're seeing now is completely consistent with what we expect in a warmer world because all of our models show us that heat waves will become intense, more frequent, and they'll last longer.

COBIELLA: This heat wave should taper off in the East by the weekend. But in the Midwest, the misery will continue. Kelly Cobiella, CBS News, Atlanta.

—Brent Baker is Vice President for Research and Publications at the Media Research Center