Volcanism, climatic change, and the geologic record

Abstract

There is some evidence for correlation between climate cooling and enhanced volcanism on time scales from decades to 106 years, but problems in dating the episodes make it difficult to establish cause-and-effect relationships. Climate cooling for longer than the stratospheric residence time of the areosols (a few years) requires that positive feedback mechanisms, such as snow/ice-albedo feedback, come into play, or that climatically significant eruptions in the past were more closely spaced in time than in recent centuries. On long time scales (107-108 years), release of CO2 through subduction-zone volcanism is a major control of climate. Intervals of rapid ocean-floor accretion (and subduction) correlate with times of increased volcanism, high sea levels and warm global climates. Accretion-rate data can be used in biogeochemical models to estimate paleoatmospheric CO2 levels. -from Author