The sky is falling, literally!

The sky is falling, literally!

Gradually shrinking

 It seems the sky above your head is falling gradually, as scientists have found the height of clouds has been shrinking gradually over the last 10 years.

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, researchers said.

Clouds that are lower in the atmosphere would allow Earth to cool more efficiently, potentially offsetting some of the warming caused by greenhouse gases, they pointed out.

“We don’t know exactly what causes the cloud heights to lower,” study researcher Roger Davies, of the University of Auckland in New Zealand, was quoted as saying by LiveScience.

“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, the researchers said.

No one fully understands how clouds will respond to a warming climate. But the Multi-angle Imaging SpectroRadiometer on NASA’s Terra spacecraft has been watching Earth’s clouds for over a decade.

Now, Davies and his colleagues have analysed the device’s first 10 years of cloud-top height measurements from March 2000 to February 2010.

They found that global average cloud height decreased by around one per cent over the decade, a distance of 100 to 130 feet. Most of the reduction stemmed from fewer clouds forming at very high altitudes.

The Terra satellite is set to continue collecting data through the rest of this decade, which will help determine whether or not the cloud lowering is a consistent trend, the researchers reported in the journal Geophysical Research Letters.