Statistical Evidence on the Influence of Sunspots and Volcanic Dust on Long-Term Temperature Records

Abstract

Abstract Over the years many claims have been made of relationships between climate and volcanic dust veils or sunspots. Sunspot proponents have claimed significant climatic variations on the time scales of 11 years, 22 years, and other multiples of the duration of the sunspot cycle (e.g., King, 1973a,b). Current hypotheses of a 22-year drought cycle in the Great Plains area is a contemporary example of such speculations (Thompson, 1973). Supporters of volcanic dust effects point to reportedly marked temperature drops alter large volcanic eruptions followed by a gradual return to preexplosion levels [e.g., Mitchell (1961) or Lamb (1970) or more recently, Oliver (1976)]. For the case of volcanic dust a plausible physical mechanism has always been at hand: the absorptive and scattering properties of volcanic particles. However, proposed mechanisms for the suggested sunspot-climate link have remained highly speculative, underlining the need for particularly critical assessments when such relationships are su...