Research Summary: 

I study the Earth's carbon cycle on timescales from 5 years to 100,000 years. My main interests are in:

1. fundamental mechanisms of the carbon cycle and

2. how humans are altering these mechanisms through combustion of fossil fuel, land use change, and erosion.

My research uses natural radiocarbon (¹⁴C, half-life 5730 years) coupled with organic geochemical tools like wet chemical extractions, ¹³C NMR, physical separations, chromatographic and spectroscopic studies to address problems related to carbon and climate. By combining geochemical tools with a chronometer (¹⁴C) I can answer questions about both mechanisms and timescales of carbon movement between reservoirs. I am particularly interested in problems related to the movement of carbon between fast and intermediate-cycling carbon pools, including the terrestrial biosphere, the atmosphere, rivers, and ocean sediments. New research in my lab includes the development of organic carbon oxidation state (C_ox) as a tracer of Earth system processes.