The hydrosphere and lithosphere intersect in a zone a few kilometres wide at the earth's surface, resulting in the formation of magmas, metamorphic rocks and mineral deposits, and placing important controls on the evolution of landscapes. This interaction imparts chemistry to waters and provides the essential environment for ecosystems to flourish. It affects the transport and fate of pollutants in groundwater and surface water systems, influences the stability of landscapes and sub-surface structures and provides an important feedback mechanism for controlling carbon dioxide levels in the atmosphere. New analytical instrumentation and methods have allowed unprecedented characterization of the sources of, and processes affecting, the chemical constituents of water. Novel field and laboratory-based approaches have revealed the atomic level of the mineral-water interface and the critical role that microbes play in many water-rock interactions, including the toxification and detoxification of the environment. Our window into the higher temperature and pressure world of geothermal waters increasingly widens as new theoretical and experimental approaches are perfected.The need to confront society's impact on the environment has led to innovative field-based and theoretical studies of our ability to sequester waste products effectively and safely within the earth, to develop new methods to treat wastes before they are returned to the environment, and to greater understanding of the limits of sustainability of our water and mineral resources. In 2007, WRI-12 attracted more than 400 geoscientists from over 25 countries to Kunming, China. For this WRI symposium, approximately half of the 350 papers were from Chinese scientists, attesting to the increasing impact their science is having on the world stage.