HR: 16:00h
AN: PP24A-01    [Abstracts]
TI: Volcanoes and Climate
AU: * Crowley, T J
EM: tcrowley@duke.edu
AF: Duke University, Old Chem Bldg Rm 103 PO Box 90227, Durham, NC 27708 United States
AB: Midway in a prolific career Jim Kennett was among the first, if not the first, to suggest that certain stages of Cenozoic cooling, in particular the Oligocene, seemed to be associated with enhanced volcanism and tectonism. To my knowledge this inference has not been followed up in any serious way. Part of the problem was a lack of understanding how brief-lived events could have created such a large scale transition on much longer time scales. Some recent work suggests that one possible explanation is that pulses of volcanism may have pushed the climate system over a critical threshold that it may have reached via, for example, reductions in atmospheric CO2. From this perspective volcanism was a trigger, not a cause, setting the timing for an event, but not the ultimate explanation for the event. On much shorter time scales volcanism has enjoyed a great surge of interest, as there are now good indications that it played a significant role in Little Ice Age cooling. The unusual pulse of volcanism from 1963-1991 (four significant eruptions) also played a role in retarding detection of the expected anthropogenic greenhouse warming until the 1990s, even though early model projections had suggested that the warming should have occurred earlier. Application of ice core results to volcanism has attracted an increasing level of interest, especially since it has now been shown that ice core sulphate levels can be convincingly calibrated with the instrumental record.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 8409 Atmospheric effects (0370)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005