Volcanism and Climate

The impact of volcanism on weather and climate is unequivocally documented by temporal correlations in both historical and prehistorical records. Although volcanic events have been traced far back in time, only Quaternary and Holocene records provide the detail and resolution necessary to address many otherwise ambiguous connections. Both observations and modeling suggest inherent relationships among the geosphere, hydrosphere, cryosphere, and atmosphere, setting the stage for various climate responses commonly incorporating complex feedback loop systems and their elusive dependence on proximity to thresholds. Furthermore, both volcanism and climate may trigger secondary phenomena of sometimes catastrophic nature. The cause-and-effect sequence is particularly intriguing, i.e., whether volcanism forces climate or changing climate forces volcanism or if, in fact, either or both can occur in nature. This overview is based on a number of studies that comprehensively address the overall theme (e.g., Cas and Wright, 1987; Sigurdsson, 1999; Robock, 2000; Schmincke, 2004; Oppenheimer, 2011; McGuire, 2012; Cashman and Sparks, 2013; and references therein).