My research focuses on the role of inland waters in the global carbon cycle and on hydrologic, climatic, and disturbance controls on the biogeochemical cycling, sequestration, transport, and surface-atmosphere exchange of aquatic carbon. Investigations conducted by me and my research group address a broad range of field, laboratory and modeling studies, including the transport of inorganic and organic carbon by surface and subsurface waters; the production, consumption, and atmospheric exchange of carbon dioxide and methane by streams, rivers, lakes, reservoirs, and soils; the effects of climate warming, permafrost thaw, and other disturbances on the carbon cycle of subarctic and boreal regions; and extrapolation of inland waters carbon biogeochemical processes and rates of carbon exchange from site to regional, continental, and global scales. I lead USGS LandCarbon investigations of Ecosystem Carbon Sequestration and Greenhouse Gas Exchange by Inland Waters of the USA and am also the Principal Investigator of the NASA Arctic-Boreal Vulnerability Experiment (ABoVE) project "Aquatic Vulnerabilites of Inland Waters and the Aquatic Carbon Cycle to Changing Permafrost and Climate across Boreal North America".