Dr. Roy Spencer, a meteorologist at the University of Alabama and someone who works frequently with NASA’s science team, is the keynote speaker at lunch. He blogs here and explains very well why the IPCC model predicts too much warming; in fact, his latest post “A Layman’s Explanation of Why Global Warming Predictions by Climate Models are Wrong” is worth taking a look.
His talk discusses why we cannot trust the IPCC climate models for global warming predictions. But he notes first that global warming skeptics have many different theories. Spencer gives his own account and he does acknowledge that carbon dioxide is a minor greenhouse gas and one that’s atmospheric concentration is increasing. Therefore, some warming should result, but the million dollar question is how much?
All climate models exhibit climate feedback; that is, how water vapor and the clouds react to increased warming and increased carbon dioxide. For instance, increasing carbon dioxide could potentially decrease cloud coverage and let more sunlight in. Conversely, an increase in CO2 could create more clouds, decrease sunlight and create a negative feedback. Spencer says, “Without positive feedback, manmade global warming becomes a non-issue.”
The IPCC climate report strongly believes in positive climate feedback. The underlying question now becomes is it man’s contribution of increased carbon that leads to this positive feedback. Perhaps maybe the sun and ocean could have had stronger effects. This mix up of cause and effect led Spencer to publish a paper, reviewed by two IPCC scientists, that shows manmade global warming could be a false alarm. We’re talking half a degree C temperature increase as opposed to three degrees C by 2100.
If not carbon dioxide, what does cause global warming? Spencer argues fewer clouds. But what causes a change in cloudiness? Spencer points to the Pacific Decadal Oscillation (PDO). The PDO index follows the cycle of cloud coverage. But the IPCC ignores natural variations in clouds and thus natural variations in climate. By creating an illusion of positive feedback, the IPCC scientists significantly overestimate warming predictions. If the climate system is as sensitive as the IPCC report says it is, then carbon dioxide would have a very strong effect on warming and cooling. It’s the same reason Energy Secretary Steven Chu suggested we paint all our rooftops white. But it’s not that sensitive because so many other variables exist.
During the question and answer session, a climatologist said his paper was flawless but was rejected by peer reviewers. Roy Spencer echoed those comments saying there is an increasing bias within scientific journals that publish global warming skepticism findings. A physicist who studies greenhouse gas effects at our lunch table admitted the same thing happened to him.
Although the scientific debate behind global warming is not over, many are treating it that way. And it’s that controlled message that could lead to one of the largest regulatory and economically painful undertakings in U.S. history in a cap and trade bill.