My research uses stable isotope geochemistry and reactive transport modeling to investigate how terrestrial water and carbon cycles are coupled in the modern and during key intervals of Earth’s history. Current research topics include (1) quantifying links between chemical weathering rates and organic carbon cycling in soils; (2) evolution of the silicate weathering feedback and its relation to climate through Earth history; (3) characterizing the controls of CO₂ fluxes and variability from soils and streams; and (4) using stable isotopes of water to quantify evapotranspiration fluxes in modern- and paleo-terrestrial systems.