This session focuses on processes characterized by feedback interaction of two or more components of Earths climate system. Participating scientists include geologists, biologists, astrobiologists, oceanographers, and ecologists from the US, the UK, Denmark, Germany, and Belgium.
John Shepherd of the Southampton Oceanography Centre, University of Southampton, will set the stage in the opening talk by discussing the challenges of climate modeling, given that all major components of the Earth system play important roles. A number of subsequent papers consider feedback mechanisms that regulate atmospheric oxygen and carbon dioxide levels, and several climate models are discussed. A few highlights are noted below.
James Alcock, Environmental Sciences, Penn State Abington College, takes an interesting look at tropical rainforest stability, derived in part from the ability to hold and recycle water. He will discuss positive feedback in the form of human activity that destabilizes the system, eventually leading to ecosystem collapse. Model testing suggests that a point of no return can be reached within one to two decades, resulting in unimaginable loss to global biodiversity.
Andr Berger from the Institut dAstronomies et de Gophysique G. Lemaitre, Universit Catholique de Louvain, discusses how to simulate glacial-interglacial cycles with a climate model which includes, in a simplified way, the atmosphere, hydrosphere, cryosphere, and lithosphere, and their interactions. Simulations of climate over the next 130 Kyr. suggest that the present interglacial will probably be a particularly long one (50 Kyr).
Two papers examine biotic feedback mechanisms and their implications for James Lovelocks Gaia theory of Earth as a self-regulating mechanism.
'"/>
Contact: Ann Cairns
acairns@geosociety.org
303-447-2020 x 1156
Geological Society of America
24-May-2001