‘Cloud feedback’ will play major role in global warming: Study

WASHINGTON - Till now, one of the biggest uncertainties in climate change studies was whether clouds trap more heat or offer a net cooling.

And researchers were not able to figure out which of these effects is more important overall.

However, a new study has revealed that changes in clouds actually intensified the warming of the planet due to human activities.

Prof Andrew Dessler of the Texas A and M University said that warming due to elevated greenhouse gases would cause clouds to trap more heat, which will lead to additional warming.

“It’s a vicious cycle - warmer temperatures mean clouds trap more heat, which in turn leads to even more warming,” he said.

The process, known as the ‘cloud feedback’, is predicted to be responsible for a significant portion of the warming over the next century.

Dessler used measurements from the Clouds and the Earth’s Radiant Energy System (CERES) instrument onboard NASA’s Terra satellite to calculate the amount of energy trapped by clouds as the climate varied over the last decade.

He also used meteorological analyses provided by NASA’s Modern Era Retrospective-Analysis for Research and Applications (MERRA) and by the European Center for Medium-Range Weather Forecasts.

While climate models had long predicted that the cloud feedback would amplify warming from human activities, until recently it was impossible to test the models using observations.

“This work suggests that climate models are doing a pretty decent job simulating how clouds respond to changing climates,” said Dessler.

Some prominent climate sceptics have recently been arguing that clouds would act to stabilize the climate, thereby preventing greenhouse gases from causing significant warming.

“Based on my results, I think the chances that clouds will save us from dramatic climate change are pretty low,” explained Dessler.

“In fact, my work shows that clouds will likely be amplifying the warming from human activities,” he added.

“I think we can be pretty confident that temperatures will rise by several degrees Celsius over the next century if we continue our present trajectory of greenhouse gas emissions,” said Dessler.

The study is published in the current issue of Science magazine. (ANI)