Earth’s Clouds Are Getting Lower, NASA Satellite FindsFebruary
22, 2012 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. Lead researcher Roger Davies
said that while the record is too short to be definitive, it
provides a hint that something