Abstract

Volcanic eruptions have a significant potential to affect the climate system, environment and society. I will summarize my work on volcanic sulfur emissions from flood lava eruptions of different magnitudes and durations. I will discuss the long-range transport and air quality effects of sulfur emitted from the ongoing eruption at Holuhraun (Bárðarbunga volcano, Iceland). Holuhraun is the first flood lava eruption in Iceland since the 1783-1784 AD Laki eruption, which had significant effects on climate and the environment of the 1780s. Using a global aerosol microphysics model (GLOMAP) to simulate a future Laki-type eruption, I show that such an eruption could have the potential to substantially degrade air quality across Europe. Based on the predicted changes in air quality due to the eruption, I show that up to 142,000 additional cardiopulmonary fatalities could occur in Europe. Such a volcanic air pollution event would therefore be a severe health hazard, increasing excess mortality in Europe on a scale that exceeds mortality due to seasonal influenza. Finally, I will present Earth system model simulations of the sulfur-induced environmental effects of decade to century-long continental flood basalt eruption episodes in the geological past. These modeling results are then used to place constraints on the likely environmental effects and habitability by simulating different eruption frequencies and durations as well as hiatus periods, and by comparing to the proxy records.