Oct. 24, 1996
Vol. 16, No. 4

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    Oceanographer awarded Packard fellowship

    Funds will support study of carbon dioxide in world's oceans Oceanographer David Archer has been awarded a five-year, $500,000 fellowship from the David and Lucile Packard Foundation.

    Archer, Assistant Professor in Geophysical Sciences and Adjunct Professor in Environmental Sciences, is modeling the physical and chemical transport of carbon dioxide in the world's oceans.

    Variations in the atmosphere's carbon dioxide have been linked to global temperatures: the Last Glacial Maximum time, 20,000 years ago, had markedly lower levels of carbon dioxide in the atmosphere then we see today. Archer's work focuses on learning about the balance between oceanic and atmospheric carbon dioxide levels in the past to better understand and predict the impact changing levels will have on our future climate.

    "We can't forecast what carbon dioxide will do in the future until we know why it was lower during glacial times," said Archer. "And a big question is, what was the circulation in the ocean?"

    Archer's research predicts that much of the extra carbon dioxide added to the atmosphere by such anthropogenic activities as the burning of fossil fuels will be absorbed by the oceans after about 200 years. However, as much as 8 percent of the human-generated carbon dioxide will remain in the atmosphere for the next 200,000 years.

    "That means that the amount of carbon dioxide generated by one gallon out of every tank of gasoline essentially never leaves the atmosphere," said Archer.

    The implications of rising carbon dioxide levels are not fully understood. "There have been times in the geologic past when the earth has had much higher concentrations of carbon dioxide in the atmosphere and life has flourished -- for example, during the Cretaceous period when dinosaurs were alive," Archer said. "It's not having a warmer climate that's a problem as much as the transition. Human communities have developed in areas that are suitable for agriculture, for example. If an area that has in the past gotten a lot of rain suddenly begins to experience prolonged and unremitting drought, it will be devastating to society."

    Carbon dioxide dissolves in the surface water of the oceans and is transported to deeper waters by convection or by biological processes. It dissolves more readily in cold water than warm. Waters that are warming up tend to release carbon dioxide, whereas cold water absorbs it from the atmosphere. Before the burning of fossil fuels, this flux was balanced, said Archer.

    The United States recently signed the Framework Convention on Climate Change, an outgrowth of the Rio Earth Summit, committing the United States to limit the release of carbon dioxide in the future as required to maintain atmospheric concentrations that are regarded as not harmful to life. "So the question is, how much carbon dioxide is going to be taken up by the ocean and biosphere? If we don't understand the glacial carbon dioxide, how can we predict future levels?"

    To further his goal of better modeling the processes involved in the exchange of carbon dioxide between surface water and deep water, Archer hopes to use some of the money from the Packard Foundation to support postdoctoral fellows who specialize in related fields, such as physical oceanography, as well as graduate students.

    Archer joined the Chicago faculty in 1993. He received his B.S. in biochemistry from Indiana University in 1983, and his Ph.D. in oceanography from the University of Washington in 1990. He was a postdoctoral fellow from 1990 to 1993 at the Lamont Doherty Earth Observatory of Columbia University, where he is currently adjunct professor.