MOUNTAIN GLACIERS - RECORDERS OF ATMOSPHERIC WATER-VAPOR CONTENT

A case is made that taken together, the 0.9 km lowering of tropical sn ow lines and the 8 parts per thousand reduction in the delta(18)O for tropical mountain Huascaran snowfall point to reductions in the water vapor inventory of the glacial atmosphere large enough to account for a several degree global cooling. The major weakness in this argument i s that as no means exists to estimate the change in the magnitude of t he radiative cooling term in the tropical atmosphere's heat budget, th e assumption must be made that during glacial time the magnitude of th is term was close to its present value. Changes in the inventory of at mospheric water vapor are tantalizing for they offer not only a means of cooling the glacial Earth but also a means of producing the abrupt changes in global climate, now well documented in climate record.