|
Edward J.
Brook |
|
Department of Geology, Washington State University Presentation
Summary: Cores through the polar ice sheets provide a remarkable archive of past climate conditions and a context for understanding human impacts on climate. They document climate change on time scales as short as a few years and as long as hundreds of thousands of years. Studies of the isotopic composition of the ice, dust content, other impurities, and trapped gases provide a detailed description of major glacial-interglacial changes in Earth's climate and show clearly the link between changes in climate and biogeochemical cycles over the past 400,000 years. Ice core records also document significant shorter term ('millennial scale') climate change in exquisite detail, showing that the relatively slow pace of glacial-interglacial climate change is not the only mode of variability the Earth is capable of. With respect to the modern situation, records of greenhouse gases are perhaps most significant. These direct measurements of past atmospheric conditions show that current levels of greenhouse gases represent a significant increase above natural levels since the early 1800s, and that both the current concentrations and rates of increase are unprecedented in the past 400,000-plus years. Biographical Sketch: Edward Brook received a B.S. in Geology from Duke University in 1985, an M.S. in Geology from the University of Montana in 1988, and a Ph.D. in Chemical Oceanography from the MIT/Woods Hole Oceanographic Institution Joint Ph.D. Program in 1993. Subsequently, he was an NOAA Climate and Global Change Postdoctoral Scholar at the University of Rhode Island, and is now an Assistant Professor of Geology and Environmental Science at Washington State University. His current research interests include the history of atmospheric greenhouse gases from ice cores, chronology of northern and southern hemisphere glacial deposits, and development of geochemical tools to study earth history. Relevant Publications: Brook, E.J., J. Severinghaus, S. Harder, and
M. Bender. In press. Atmospheric methane and millennial scale
climate change, in Mechanisms of Millennial-Scale Global Climate
Change, edited by Webb et al., American Geophysical Union
Monograph Series. |