Earth's clouds are getting lower

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 the future global climate.

A consistent reduction in cloud height would allow Earth to cool to space more efficiently, reducing the surface temperature of the planet and potentially slowing the effects of global warming. This may represent a “negative feedback” mechanism — a change caused by global warming that works to counteract it. Scientists suspect this may be due to a change in the circulation patterns that give rise to cloud formation at high altitude.

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. And while the record is too short to be definitive, it provides a hint that something quite important might be going on.