Says Sancetta, "Verardo's work is important because he has uncovered a record of burning that goes beyond historical records, so we can study natural burning before human influence." This in turn will help scientists determine whether human-induced burning has different effects than natural burning, and how burning is related to changes in ecology, and perhaps evolution, on longer time scales. "Another implication of Verardo's work," adds Sancetta, "is that if a lot of the carbon [charcoal] in ocean sediments is terrestrial in origin, then it isn't marine in origin. And scientists have been studying the marine record as a major place to find out about past carbon dioxide changes. If they've been making the wrong assumptions about how much marine carbon is involved, then their estimates about carbon dioxide in the oceans may be wrong."

Current models have not been able to determine exactly how the total amount of carbon on earth is distributed. According to Verardo, "This new data sheds much-needed light on where the 'missing' carbon may lie: in ocean-bottom sediments laden with charcoal from fires on land."

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Contact: Cheryl Dybas
cdybas@nsf.gov
703-306-1070
National Science Foundation
3-Sep-1996