New paper sure to fuel what some are now calling the climate wars
By Summit Voice
SUMMIT COUNTY — A new paper published this week in Geophysical Research Letters rebuts recent claims that clouds are the root cause of climate change.
Based on a 10-year study of El Niño and La Niña cycles, Texas A&M atmospheric sciences professor Andrew Dessler says clouds act primarily as a feedback mechanism that amplifies warming from human activity.
“”The bottom line is that clouds have not replaced humans as the cause of the recent warming the Earth is experiencing,” Dessler said. “I hope my analysis puts an end to this claim that clouds are causing climate change,” he added.
Dessler was referring to a paper published late July by Dr. Roy Spencer, a climate researcher at the University of Alabama Huntsville. Spencer’s paper caused a stir in the climate science community by claiming that existing models don’t accurately portray global warming because they underestimate the amount of heat radiating from the atmosphere to outer space. Spencer also presents evidence that clouds can cause temperature changes.
This claim is is targeted by Dessler’s new study in a classic what-came-first, chicken-or-egg scenario.
Dessler studied El Niño and La Niña cycles over the past 10 years and calculated the Earth’s “energy budget” over this time. El Nino and La Nina are cyclical events, roughly every five years, when waters in the central Pacific Ocean tend to get warmer or colder. These changes have a huge impact on much of the world’s weather systems for months or even years.
“Over a century, however, clouds can indeed play an important role amplifying climate change,” Dessler added.
Spencer says the role of clouds is critical because positive cloud feedback that magnifies the effect of greenhouse gases in the atmosphere could indeed result in a “global warming armageddon.”He addresses the issues here in his blog.
But, Spencer claims, negative cloud feedback could cancel other positive feedbacks, “and relegate manmade global warming to the realm of just an academic curiosity.”
Spencer’s July paper has been challenged by most other climate scientists and the editor of the journal that published his research recently resigned, saying it shouldn’t have been published in the first place.
A small —but very vocal — minority of climate researchers claim that Dessler’s paper was rushed into publication to support a political global warming agenda. That argument is almost always inextricably linked with slurs against leading federal climate researchers like NASA’s James Hansen and other leaders like Al Gore.