Abstract
During periods of high solar radiation and reduced volcanic activity, the earth’s climate experienced generally warmer temperatures and an intensification of the hydrological cycle yielding towards increased internal circulation. Such positive modes resulted in an overall wetter and warmer climate likely promoting the prevalence of existing and widespread /Yersinia pestis/ bacteria. Resulting outbreaks of bubonic plague triggered by the occurrence of wet summer and warm spring conditions likely contribute towards explaining the enormous dispersal rate of the mid-14s century European Black Death.