Dr. Birkholzer is a world-renowned expert on evaluating the feasibility and environmental sustainability of a broad portfolio of geo-energy applications, with particular focus on the role of deep subsurface formations for radioactive waste disposal and geologic carbon sequestration. Using a combination of numerical, theoretical, observational and experimental approaches, he focuses on the complex couplings between thermal-hydrological-mechanical and chemical processes activated by subsurface energy manipulations. He strives to improve mechanistic process understanding via a combination of in situ testing and advanced physics-based modeling, while using the knowledge gained to improve subsurface energy strategies at scale and address issues of societal relevance.