Daniel Rothman; Department of Earth, Atmospheric, and Planetary Sciences; Massachusetts Institute of Technology
Excitations of Earth's Carbon Cycle
Mysterious, transient changes in the ocean's store of carbon occur intermittently throughout Earth's history. Each of these events coincides with climate change; moreover, mass extinctions are always accompanied by such events. What causes them? I suggest that many of these events are characteristic nonlinear responses of Earth's carbon cycle to influxes of carbon dioxide that exceed a critical rate. Analysis of the geologic record supports this view and a model of an excitable carbon cycle suggests how it works. Both show how the relatively slow perturbations of the geologic past may be rescaled to inform our understanding of modern environmental change at much faster timescales.