One of the most important ways that microorganisms interface with the environment is through their processing of carbon, from greenhouse gases to the synthesis and degradation of long-lasting organic compounds. In an effort to quantify how dynamic organic carbon is in natural settings, I have used modeling and analytical techniques as well as fieldwork to make the point that organic compounds are not intrinsically labile or recalcitrant, but exist on a continuum of reactivities determined by the biogeochemical setting. Specific contributions to carbon cycle research include: 

• establishing a metric (NOSC) for scaling the energy content of complex organic matter to its elemental composition. This metric has been widely used to rationalize observed patterns in the reactivity of natural organic matter;

• developing a reaction transport model to reveal the global distribution and degradation rates of organic carbon in Quaternary-aged sediments in 3D;

• working with collaborators to determine the origin and evolution of methane using isotopic bond ordering equilibria;

• collaborating with many scientists to contextualize phylogenetic representation of sedimentary microbial communities and the thermodynamic drive for carbon processing.