Christophe Tournassat holds B.Sc. and M.Sc. degrees in Earth Sciences from the Ecole Normale Supérieure de Lyon, France, a Ph.D. in Environmental Geochemistry from the University of Grenoble, France, and an "Habilitation à diriger des recherches" in Geology from the University of Nantes, France. In 2003 he joined the French Geological Survey (BRGM) as a staff Scientist until 2020. From 2010 to 2018, he has been heading the BRGM scientific program on geological barriers performances, which includes BRGM’s researches on radioactive waste storage. In 2017, Christophe Tournassat took the lead of the group "Porous Media", and then the lead of the group "Continental biogesosystems" in 2018, in the framework of the renewal of the collaboration between BRGM, CNRS and the University of Orléans in the ISTO laboratory (Institut des Science de la Terre d'Orléans). In addition Christophe Tournassat took a part-time position at the Energy Geoscience Division of the Lawrence Berkeley Laboratory in 2017, in order to pursue its collaboration with Carl Steefel and Benjamin Gilbert at LBL. In 2020, Christophe Tournassat was promoted to a Professorship position at the University of Orléans, France. His scientific interest covers a wide 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 clay-rocks.