December 10, 2001 UCSC researchers lead consortium studying ecosystem impacts of global warming By Tim Stephens With a $2.5 million grant from the National Science Foundation, UCSC researchers are leading an interdisciplinary team from seven institutions in a project to study the consequences of global warming. The five-year project focuses on a dramatic episode of global warming that took place 55 million years ago at the end of the Paleocene epoch. These fossil specimens of marine plankton called foraminifera, collected from the sea floor in the equatorial Pacific, are about 55 million years old and hold clues to the global warming episode known as the LPTM. (Image courtesy of J. Zachos) The Late Paleocene Thermal Maximum (LPTM) was one of the most abrupt and extreme global warming events in the geologic record. Over a period of several thousand years, the Earth warmed by as much as 10 degrees Celsius (18 degrees Fahrenheit), said James Zachos, professor of Earth sciences and lead investigator of the project. "The LPTM was a natural greenhouse experiment run on a global scale, which we now have the opportunity to study from beginning to end," Zachos said. The project seeks to understand how global ecosystems responded to and eventually recovered from this brief (in geologic time) episode of extreme global warming. "A more comprehensive understanding of what took place 55 million years ago will provide us with a much better appreciation of the sensitivity of biological systems to global climate change," Zachos said. In addition to Zachos, the UCSC investigators involved in the project are professor and chair of ocean sciences Peggy Delaney and associate professors of Earth sciences Paul Koch and Lisa Sloan. UCSC's Center for the Dynamics and Evolution of the Land-Sea Interface (C.DELSI), an interdisciplinary research center directed by Zachos, provided crucial support for the grant proposal and will play an important role in facilitating project-related workshops, student participation, and public outreach. The project's first workshop at UCSC is scheduled for early May. Other participants in the study are based at Pennsylvania State University, Rice University, Wesleyan University, University of North Carolina, the Smithsonian Institution, and the American Museum of Natural History. The project will also involve a team of international scientists based mainly in Europe and Asia, Zachos said. By studying the LPTM, the researchers will be able to address important questions about the consequences of global warming caused by greenhouse gases, which trap heat in the atmosphere much like the glass roof of a greenhouse. Geochemical evidence indicates that the LPTM resulted from the sudden release of trillions of tons of methane from the seafloor. Methane is itself a potent greenhouse gas, and oxidation converts it into carbon dioxide, the greenhouse gas thought to be driving the current global warming trend. "If the methane were quickly oxidized to carbon dioxide, the rate of increase in atmospheric concentrations of carbon dioxide during the LPTM would have been comparable to the current increase due to modern carbon dioxide emissions," Zachos said. The researchers plan to document how biological systems on land and in the oceans responded to the changing climate. They will also investigate how the changes in biological systems affected the global carbon cycle and the cycling of other essential elements (i.e., nutrients) in the environment. "How long does it take to remove the excess carbon from the system after it's been added? What were the mechanisms involved in that process? What was the role of the biosphere? Those are some of the questions we hope to answer," Zachos said. Return to Front Page