A study published this week in Geophysical Research Letters disproves recent claims that clouds are the root cause of climate change.
Based on a 10-year study of El Nino and La Nina cycles, Andrew Dessler, atmospheric sciences professor at the Texas A&M University, 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 had caused a stir in the climate science community. It claimed that the existing models didn't accurately portray global warming because they underestimated the amount of heat radiating from the atmosphere to the outer space. Spencer presented evidence that clouds could cause temperature changes.
Dessler studied El Nino and La Nina cycles over the past 10 years and calculated the Earth's energy budget over this time.
El Nino and La Nina are cyclical events, occurring 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.
Dessler's research, published in the journal Geophysical Research Letters, looked at 10 years' worth of data from the sky and the sea. The data, he said, showed that the ocean's influence on the Earth's climate was 20 times larger than any influence due to cloud cover changes.
Spencer said the role of clouds was critical because positive cloud feedback that magnified the effect of greenhouse gases in the atmosphere could indeed result in a global warming Armageddon.
Spencer, a scientist whose views and findings often put him outside the consensus on climate change, co-authored a report in July which said that the influence of those many variables were too strong to reliably attribute any climate change to humans.
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.