Can Northern Hemisphere Holocene volcanic events be recorded in pollen data?

Abstract

A number of major volcanic events are documented as having taken place during the post-glacial Holocene. Recent evidence suggests a link between short-term episodes of climate change and the effects of volcanic dust veils and aerosols moving in the atmosphere. Increased atmospheric opacity resulting from significant quantities of particulate (dust veils) may have resulted in 'volcanic winters', brief but significant episodes of surface temperature cooling, at a regional and perhaps a hemispheric scale, changes in stratospheric chemistry resulting from input into the atmosphere of gaseous acids are discussed. Possible impact mechanisms, both direct and indirect, of volcanic activity on vegetation are described, together with the possibility that major Holocene volcanic events may also be recorded in pollen data. Radiocarbon dated pollen levels obtained from published sites in two geographical areas, Northern Ireland and the eastern Alps, are used to outline this hypothesis. Separation between the long-term climate signal from short-term modifications induced by volcanic activity is also discussed.