Water vapour as an amplifier of the greenhouse effect: new aspects

Abstract

In view of the wide-spread negligence concerning water vapour as the most efficient greenhouse gas, its role in the recent climatic evolution is investigated. Increase of tropospheric water vapour content and rising evaporation (by about 15 %) from tropical oceans have been found in recent decades. Evidence for an accelerated hydrologic cycle is given, leading simultaneously to a remarkable intensification of the tropospheric circulation in the Northern Hemisphere. Average geostrophic wind speed at the surface and in the troposphere have increased by 6-9 % between 1967 and 1989. This (natural) internal feedback through water vapour amplifies the "dry" greenhouse effect of CO2 and other trace gases by a factor of about 5, spreading poleward from tropical oceans.

Keywords

• greenhouse gas
• water vapour
• geostrophic
• greenhouse effect
• tropical oceans
• treibhausgas
• wasserdampf
• geostrophisch
• treibhauseffekt
• tropische ozeane