HR: 16:20h
AN: GC44A-02 INVITED    [Abstracts]
TI: Ice Sheets and Abrupt Change
AU: * Alley, R B
EM: rba6@psu.edu
AF: Department of Geosciences and PSICE, Pennsylvania State University, Deike Building, University Park, PA 16802, United States
AB: The sea-level rise projections from the IPCC (AR4 SPM 2007) appeared as "Model-based range excluding future rapid dynamical changes in ice flow", and the text noted "…understanding…is too limited to provide a best estimate or an upper bound for sea level rise." Of the possible mechanisms of instability of ice sheets, attention especially focuses on loss of buttressing through ice-shelf removal, and increased lubrication through drainage of surface meltwater to the bed. Quantification of both is improving, but confident predictions are not possible. However, it does appear possible that warming over decades could reach levels that would produce large ice- sheet changes over centuries.
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1621 Cryospheric change (0776)
DE: 1641 Sea level change (1222, 1225, 4556)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting