While monitoring the G-20 protests on social media site Twitter last month, it was surprising to see a series of tweets by KDKA chief meteorologist Jeff Verszyla:

"Global Warming? NASA Scientist Leonard Weinstein uses the melting of Arctic and Greenland ice to show how CO2 cannot cause catastrophic melting in the future. In fact, both areas are well within the norm of natural variation.

"Tons of REAL SCIENTIFIC evidence to debunk the Al Gore led movement ... which is mostly politically motivated. Don't believe the hype!"

Around the same time I had noted the Twitter pages of several other people I follow getting hacked and I thought maybe someone had gotten into Verszyla's account -- www.twitter.com/verz -- and sent out those tweets. So I e-mailed him to ask if that was the case.

His response: "it was me ... posting one nugget of true science, which doesn't get the coverage it should ... since it flys [sic] in the face of the chic belief that global warming is somehow related to co2 emissions."

But that flies in the face of what mainstream scientists believe.

Peter Adams, an assistant professor in the department of civil and environmental engineering at Carnegie Mellon University and an expert in atmospheric chemistry and climate change, said he first encountered meteorologists skeptical of climate change during a lecture in Cleveland this summer. In interviews last year with the Cleveland Plain Dealer, several prominent forecasters at Cleveland TV stations, including WJW's Dick Goddard -- Cleveland's weather patriarch in the Joe DeNardo mold -- rejected assertions about human-induced warming made by the Intergovernmental Panel on Climate Change.

The IPCC was established by the United Nations Environment Programme and the World Meteorological Organization with a mandate "to provide the world with a clear scientific view on the current state of climate change and its potential environmental and socio-economic consequences," according to the IPCC Web site.

"It is safe to say that the science of how and why burning fossil fuels emits carbon dioxide and causes climate change is not a subject of any serious scientific debate," Adams said.

"The mainstream climate scientists agree that a significant fraction of the warming over the 20th century was caused by human activities. Continuing to burn fossil fuels will only accelerate those changes. In my mind it's inconceivable that we can continue burning fossil fuels and not have pretty dramatic climate changes."

The American Meteorological Society, of which Verszyla is a member, endorses the IPCC view.

"Our stance is pretty clear on this and we're in agreement with the global warming scenario as set out by the international panel," Keith Seitter, AMS executive director, told the Cleveland Plain Dealer. "Still, we think they should research all that they can. And really, there should be less and less skepticism out there as the science improves each year -- not more."

Verszyla, who has a degree in broadcast communications and English from Allegheny College and a certificate of broadcast meteorology from Mississippi State University, declined further comment this week.

"The station has no comment," wrote KDKA news director Coleen Marren in an e-mail. "Jeff was expressing his personal opinion and not that of the station or its management."

Why do some meteorologists disbelieve climate change? Adams chalks it up to cultural differences between two different fields of study.

"There are big differences between weather and climate," he said. "Weather is all about short-term variability and climate is about long-term trends and those are really governed by different processes."

He compared it to differences in other related fields.

"Let's say you have a brain aneurysm: It's the difference between a neurosurgeon and someone with a bachelor's degree in chemistry. There are a lot of degrees of expertise and I think that gets lost for the average person, who thinks, 'He's on TV and he's explaining the weather to me so why wouldn't he know about climate?' "

As for the NASA scientist Verszyla cited, Weinstein is a retired NASA senior research scientist with degrees in physics and engineering who is currently a senior research fellow at the National Institute of Aerospace. In April, Weinstein wrote "Disproving The Anthropogenic Global Warming Problem" for The Air Vent blog (http://noconsensus.wordpress.com/).

"What prediction has the AGW made that has been demonstrated, and that strongly supports the theory," Weinstein wrote. "It appears that there is NO real supporting evidence and much disagreeing evidence for the AGW theory as proposed. That is not to say there is no effect from human activity. Clearly human pollution (not greenhouse gases) is a problem. There is also almost surely some contribution to the present temperature from the increase in CO2 and [methane], but it seems to be small and not a driver of future climate. ... Any reasonable scientific analysis must conclude the basic theory wrong!!"

Eric Swanson, an associate professor of physics at the University of Pittsburgh, recently wrote a piece for the Post-Gazette's Forum section on the subject of climate change.

"The basic science that underlies it is pretty simple," he said. "Energy that drives the climate comes from the sun and carbon dioxide helps keep some of that energy on Earth and acts as a blanket, as insulation. The more carbon dioxide on Earth, the thicker the insulation and the warmer the Earth gets. At a very basic level, that's what happens.

"If you throw another log on the fire," he said, comparing that to adding carbon dioxide to the atmosphere as has happened over the past 150 years, "it will get warmer." Swanson acknowledged the climate is naturally variable but that humans have added unnatural elements to the climate.

CMU's Adams said for the lay person, climate change often comes down to a matter of who to trust.

"How do you establish authority in these kinds of questions? Is it the guy on TV with whatever credentials he has or even Weinstein and people who are real scientists and researchers who are climate skeptics, even if they are few and far between?" he said. "Even in science there is something to be said for collective wisdom and you have things like the IPCC, which is made up of people who are actively researching this topic, and it represents the overwhelming majority of science opinion."

In advance of the Nov. 15 premiere of AMC's new "Prisoner" miniseries, Comcast has made all 17 episodes of the original "Prisoner" available on demand through Nov. 30. ... Fox will shutter its Fox Reality Channel next year and rebrand it as something different that has not yet been announced. ... William Worms of Coraopolis will appear Wednesday on "The Price Is Right" (11 a.m. weekdays, KDKA). ... Former Pittsburgher Tom Wallisch, a 22-year-old professional skier, will be featured on "The Alli Show" (11 p.m. Saturday, MTV2).

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