Climate, Water Vapor, and Volcanic Eruptions

The objective is to stimulate research into alternative mechanisms that might increase sustained water vapor in the atmosphere and thus drive climate warming. Toward this end a period from the prior interglacial from 130,000 BCE to 110,000 BCE is examined to show that temperature peaks and atmospheric concentration of CO2 reaches its maximum level, then temperature falls by 7 to 8 degrees C over 13,000 years while atmospheric CO2 concentration remains high and constant. Mechanisms that might support this cooling while CO2 remains high and constant are considered. It is noted that the primary assumed source of climate warming is a sustained higher level of water vapor. Current measurements of water vapor are examined. An apparent connection with volcanic eruptions having Volcanic Explosivity Index (VEI) of 5 or greater is noted in the water vapor data for the upper atmosphere. This is suggested as a mechanism that contaminates our atmospheric water vapor measurements to induce a high level of noise from a source disconnected from climate. This noise interferes with efforts to determine or verify the source of sustained atmospheric water vapor. Mechanisms that might cause climate warming while bypassing a CO2 forcing are suggested that involve variations in cloud cover.