Christophe Tournassat is currently a Visiting Faculty in the Energy Geosciences Division, Earth and Environmental Sciences Area at Berkeley Laboratory. He is a Professor at the University of Orléans, France, where he leads the group on “Continental Biogeosystems” at the Institut des Sciences de la Terre d’Orléans (ISTO). His scientific interest covers a range of topics from thermodynamics and kinetics of low temperature water/solutes/rock interactions to multi-scale numerical modeling of retention and transfer processes in geological media. He co-develops, with Carl Steefel, the code CrunchClay, which can simulate coupled non-Fickian/non-Darcian transport together with reactive processes in nanoporous media. Christophe Tournassat is associate editor of Geochimica et Cosmochimica Acta, and is member of the editorial board of Applied Clay science.