HR: 14:45h
AN: U23A-04    [Abstracts]
TI: Biogeologic Carbon Sequestration - a Cost-Effective Proposal
AU: * Shaw, G H
EM: shawg@union.edu
AF: Union College Geology Department, Union College, Schenectady, NY 12309, United States
AU: Kuhns, R
EM: KuhnsRJ@bv.com
AF: Black and Veatch, Sustainable Business Development, Geology, 601 Walnut Street, Suite 550W, Philadelphia, PA 19106, United States
AB: Carbon sequestration has been proposed as a strategy for reducing the impact of carbon dioxide emissions from burning of fossil fuels. There are two main routes: 1) capture CO₂ emissions from power plants or other large point sources followed by some form of "burial/sequestration", and 2) extraction of CO₂ from the ambient atmosphere (involving substantial concentration relative to atmospheric levels) also followed by burial/sequestration. In either case the goal is to achieve significant long-term isolation of CO₂ at an economically sustainable price, perhaps measured by some "market price" for CO₂, such as the European carbon futures market, where the price is now (2/3/09) about $14-15/tonne of CO₂. The second approach, removal of CO₂ from the atmosphere, has the potential benefit of reversing the previous buildup of atmospheric CO₂, and perhaps even providing a means to "adjust" terrestrial climate by regulating atmospheric CO₂ concentrations. For the present, ideas of planetary "geo-engineering" are not as popular as reducing the impact of continued CO₂ emissions. In fact, the energy and capital costs of extraction from a dilute atmosphere appear to make this approach uneconomical. Proposals to fertilize the open ocean suffer from concerns about long term ecosystem effects, to say nothing of a lack of verifiability. There is, however, an approach using biological systems that can not only extract significant amounts of CO₂, but can do so cost-effectively. Lakes are known in which primary productivity approaches or exceeds 1gm C/cm²-yr. This equates to removal of 35,000 tonnes of CO₂ per km² per year, with a "market value" of about $500,000/yr. Such productivity only occurs under highly eutrophic conditions, and presumably requires significant nutrient additions. As such it would be unthinkable to pursue this technique on a large scale in extant lakes. If, however, it is possible to produce one or more large artificial lakes under acceptable conditions it is conceivable that this approach to carbon sequestration could prove invaluable in both the near and long term.
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0428 Carbon cycling (4806)
DE: 0458 Limnology (1845, 4239, 4942)
DE: 1610 Atmosphere (0315, 0325)
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
SC: Union [U]
MN: 2009 Joint Assembly