From the land to the rivers to the sea: How biogeochemical cycles have regulated the global climate system throughout Earth history
Inaugural lecture by Cabot Institute Director Professor Rich Pancost
The Earth's climatic and environmental state is governed by the interplay of geological, biological and chemical processes, many of which have co-evolved through the history of our planet. Elevated carbon dioxide concentrations, both today and in the past, cause the Earth to warm, which in turn brings about a complex cascade of biogeochemical consequences, from enhanced methane flux in wetlands to erosion of the landscape to the burial of organic matter in anoxic oceans. These responses act as either positive or negative feedbacks on the climate system and influence (and are influenced) the evolution of life. I have studied how these interactions have changed through Earth history using the molecular remains of plants and microorganisms, archived in peat, lake and marine sediments. These biomarkers - or molecular fossils - document changes in carbon dioxide levels, temperature, rainfall, microbial ecology and the oxygen content of the oceans. In collaboration with biologists, climate modellers and biogeochemists, we can explore the Earth System, defining its critical characteristics and thresholds, the potential risks arising from human activity, and the increasing uncertainty in our ability to forecast future environmental change.
This event was organised by PACE.