Geerat Vermeij, from the Department of Geology at the University of California, Davis, will consider how patterns of ecological feedback between herbivores and carnivores that result in a progressive intensification of nutrient recycling in the oceans have been a dominant theme in the history of life and have exerted an important top-down (as opposed to bottom-up) evolutionary and ecological control mechanism.
SESSION 28: ANTHROPOGENIC MODIFICATIONS TO THE EARTH SYSTEM.
Tuesday, June 26
Abstracts: http://gsa.confex.com/gsa/2001ESP/finalprogram/session_152.htm
Poster Session 27 abstracts: http://gsa.confex.com/gsa/2001ESP/finalprogram/session_988.htm.
The human presence on Earth has greatly impacted the environment for better or worse. Geoscientists in this session will consider a wide variety of evidence for the nature, magnitude, and implications of human impact on our planet for the past, present, and future.
Fred T. Mackenzie, Professor of Sedimentary and Global Geochemistry from the Department of Oceanography at the University of Hawaii, will begin the session by looking at how human activities influenced the biogeochemical cycles of carbon, phosphorus, and nitrogen in the surface of the Earth since 1840. This will be quite interesting for those who would like to know what the unperturbed Earth system was like, and who also want to understand the fate of these elements through projections to the year 2040.
Timothy M. Lenton, Centre for Ecology and Hydrology at the Edinburgh Research Station, will speak about positive feedbacks in the global carbon cycle that may make it more difficult for the oceans and atmosphere to absorb anthropogen
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Contact: Ann Cairns
acairns@geosociety.org
303-447-2020 ext1156
Geological Society of America
13-Jun-2001