Since 1800 atmospheric CO2 concentrations have increased from roughly 280 ppmv to 380 ppmv, primarily as a result of fossil fuel burning and deforestation. Projections by the Intergovernmental Panel on Climate Change indicate that these concentrations will increase to about 700 ppmv by the year 2100. At current rates of consumption virtually all fossil fuels will have been burned within the next 200 years, and atmospheric CO2 concentrations are predicted to rise to about 1,900 ppmv by the year 2300. On a time scale of several tens of thousands of years over 90% of this CO2 will be absorbed by the oceans, and on a timescale of hundreds of thousands of years most of the remainder will be neutralized by weathering processing involving silicate rocks. However, on a timescale of several thousand years atmospheric CO2 concentrations will be high enough to raise global temperatures by 5-10oC and dramatically reduce the pH of the oceans‚ surface waters. The rise in atmospheric temperatures will be greatest at high latitudes, and the associated decrease in the thermal gradient between the poles and tropics will cause zonal wind systems to slacken and alter circulation and mixing processes in the ocean. The oceans will become more thermally stratified as surface waters warm. The combination of increased thermal stratification and slackened wind systems will reduce the rate of nutrient delivery to the oceans‚ surface waters via turbulent mixing and upwelling. The result will be a decrease in primary and secondary production in open ocean and upwelling systems.
Presenter:
Edward A. Laws, P.h.D.
Director, Pacific Research Center for Marine Biomedicine,
University of Hawaii
Dean, School of the Coast and Environment,
Louisiana State University
Friday, June 30, 2006
11:00 a.m.
Pacific Ocean Science & Technology Building 723
Refreshments will be served after the seminar in POST 121
The Pacific Research Center for Marine Biomedicine (PRCMB) is a newly established center at the University of Hawaii dedicated to trans-disciplinary research designed to gain new knowledge about the profound impacts of the ocean on human health. The Center is funded by the National Science Foundation (OCE04-32479) and the National Institute of Environmental Health Sciences (P50ES012740).
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