Carbon and Climate

Lessons from Wyoming's Past

May 15 (Tuesday), 6 p.m., Teton Co. Library Auditorium – Open to Public. Presentation: Carbon and Climate: Lessons from Wyoming’s past, Presented by Gabriel Bowen, University of Utah

Anthropogenic emissions of CO2 are now a primary driver of the climate system, and the future path of environmental change on Earth will depend on the fate of this carbon. The geological record tells us that ultimately anthropogenic carbon will be sequestered as limestone and organic deposits in rocks, but the timescale for this process is millions of years. What happens in the meantime? A huge amount of effort has been put into understanding carbon cycle feedbacks involving the oceans, soils, and vegetation, but studies of modern systems provide only a glimpse short-term changes. Can the geologic record bridge this gap, and reveal information on how these systems respond to and shape the impacts of global climate events?

 

Abundant evidence now documents terrestrial ecosystem change during a ~150 thousand year period of global climate warming at the Paleocene-Eocene boundary (the Paleocene-Eocene thermal maximum, PETM). Data from Wyoming’s Bighorn Basin, where some of the best-studied deposits are found, point to ubiquitous warming, dramatic changes in seasonal precipitation, and reorganization of biological communities. But the fossil soil sequences preserved in the Bighorn and other basins worldwide also reveal more subtle information on changing biogeochemical processes in these ancient ecosystems. As climate and plant communities shifted, the ability of ancient soils to capture and store organic carbon collapsed. What drove these changes, when and how did these systems recover, and what was the impact on the Earth’s climate? This talk will explore the evidence suggesting that terrestrial ecosystems – plants and soils – played a major role in guiding our planet’s response to a ‘paleoclimate catastrophe’ and could amplify the impacts of human activities on our future.