The Sky is Falling?

Shrinking Sky! Cloud Tops Dropping Closer to Earth, NASA Satellite Finds

Stephanie Pappas, LiveScience Senior Writer
Date: 22 February 2012 Time: 04:47 PM ET
Clouds in the sky at sunset.
The average height of clouds has dropped by about 1 percent in the last decade, new research finds.
CREDIT: Sebastian KaulitzkiShutterstock

The sky is falling… sort of. Over the last 10 years, the height of clouds has been shrinking, according to new research.

The time frame is short, but if future observations show that clouds are truly getting lower, it could have an important effect on global climate change. Clouds that are lower in the atmosphere would allow Earth to cool more efficiently, potentially offsetting some of the warming caused by greenhouse gases.

“We don’t know exactly what causes the cloud heights to lower,” study researcher Roger Davies of the University of Auckland in New Zealand said in a statement. “But it must be due to a change in the circulation patterns that give rise to cloud formation at high altitude.”

Clouds are a wildcard in understanding Earth’s climate. Ephemeral as they are, they’re difficult to track over time, and factors such as height and location make a big difference in whether clouds will slow the effects of global warming or exacerbate them. And no one fully understands how clouds will respond to a warming climate.