Geologic Analogs: Their Value and Limitations in Carbon Dioxide Research

Abstract

The CO2 research community has recently shown much interest in the use of geologic analogs to verify climate model predictions. This application rests, of course, on the premise that both climate and atmospheric CO2 have varied in the geologic past. Climate variability is widely documented in the geologic record, and CO2 changes have recently been documented in ice cores. Although there is no other direct evidence for CO2 variations in the geologic past, the relatively small size and short residence time of the atmospheric CO2 reservoir suggest strongly that it must have been sensitive to perturbations in the larger reservoirs with which it exchanges.