HR: 14:55h
AN: B53E-06    [Abstracts]
TI: The role of human-induced climate change in the 2005 Caribbean coral bleaching event and the implications for the future
AU: * Donner, S D
EM: sddonner@princeton.edu
AF: Princeton University, Woodrow Wilson School of Public and International Affairs, Princeton, NJ 08544, United States
AU: Knutson, T R
EM: Tom.Knutson@noaa.gov
AF: Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, Princeton, NJ 08542, United States
AU: Oppenheimer, M
EM: omichael@princeton.edu
AF: Princeton University, Woodrow Wilson School of Public and International Affairs, Princeton, NJ 08542, United States
AB: Episodes of mass coral bleaching in recent decades have been attributed to periods of anomalously warm ocean temperatures. In 2005, the sea surface temperature (SST) anomaly in the tropical North Atlantic that contributed to the strong hurricane season caused widespread coral bleaching in the eastern Caribbean. In this study, we used the GFDL global climate models to evaluate the contribution of natural climate variability and anthropogenic forcing to the thermal stress that caused the 2005 coral bleaching event. Historical temperature data and simulations for the 1870-2000 period show that the observed warming in the region is unlikely to be due to unforced climate variability alone. Simulation of background climate variability suggests that anthropogenic warming may have increased the probability of occurrence of significant thermal stress events for corals in this region by an order of magnitude. Under scenarios of future greenhouse gas emissions, mass coral bleaching in the eastern Caribbean may become a biannual event in 20-30 years. However, if corals and their symbionts can adapt by 1 - 1.5°C, such mass bleaching events may not begin to recur at potentially harmful intervals until the latter half of the century. The delay could enable more time to alter the path of greenhouse gas emissions, although long-term "committed warming" even after stabilization of atmospheric CO₂ levels may still represent an additional long-term threat to corals. These results suggest that protecting coral reefs from climate change will require both managing local pressures on reefs, in order to increase resilience to committed warming, and reducing greenhouse gas emissions.
DE: 1626 Global climate models (3337, 4928)
DE: 1630 Impacts of global change (1225)
DE: 1635 Oceans (1616, 3305, 4215, 4513)
DE: 4215 Climate and interannual variability (1616, 1635, 3305, 3309, 4513)
DE: 4220 Coral reef systems (4916)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting