Abstract

Volcanic eruptions can be viewed as experiments with our climate system, where the radiative balance of the planet is perturbed on the timescale of years. Investigating the wide-ranging responses to these individual events can improve understanding of the feedbacks, processes, and sensitivities of the climate system to sulfuric acid aerosols. Our best records of past volcanic eruptions come from polar ice cores: records of sulfate concentrations and isotopes inform sulfur aerosol loads and the geochemistry of small volcanic ash particles, or ‘cryptotephra’, enable identification of volcanic source. Here I will reconstruct the forcing from some of the major volcanic eruptions over the last 2,500 years, highlighting the strong sensitivity of Northern Hemisphere summer temperatures to Northern Hemisphere extratropical eruptions. Looking further back in time, I will investigate the climate response to some of the largest super eruptions in the past 100,000 years.