Nature looks high and low at the way clouds have changed since the 1980s – as global-warming models predicted:
An analysis of satellite data has found that, since the early 1980s, clouds have shifted towards Earth’s poles and cloud tops have extended higher into the atmosphere.
The changes match what climate models predict and are a rare step forward among much scientific uncertainty about how clouds will behave in a warming world
“It’s really the first credible evidence that we have of climate change and clouds in the observed record,” says Joel Norris, an atmospheric scientist at the Scripps Institution of Oceanography in La Jolla, California.
The scientists used two long-term databases of cloud cover, along with measures of water content over the oceans and of Earth’s reflectivity — or how much sunlight the planet’s surface throws back into space.
By 2009, the team found that there were fewer clouds over the mid-latitudes than there had been in 1983. That finding meshes with climate predictions that dry zones will expand out of the subtropics and push storms towards the poles. The team also found that cloud tops rose higher in the atmosphere by the end of the 2000s, again as predicted for a warming atmosphere.