"Earth's clouds got a little lower - about one percent on average - during the first decade of this century, finds a new NASA-funded university study based on NASA satellite data. The results have potential implications for future global climate."
"Scientists at the University of Auckland in New Zealand analyzed the first 10 years of global cloud-top height measurements (from March 2000 to February 2010) from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra spacecraft.
The study, published recently in the journal Geophysical Research Letters, revealed an overall trend of decreasing cloud height. Global average cloud height declined by around one percent over the decade, or by around 100 to 130 feet (30 to 40 meters).
Most of the reduction was due to fewer clouds occurring at very high altitudes."
Alan Buis writes for NASA's Jet Propulsion Lab in Space Daily February 23, 2012.