Weathering is the chemical and physical alteration of rock at the surface of the Earth, but its importance is felt well beyond the rock itself. The repercussions of weathering echo throughout the Earth sciences, from ecology to climatology, from geomorphology to geochemistry. This article outlines how weathering interacts with various geoscience disciplines across a huge range of scales, both spatial and temporal. It traces the evolution of scientific thinking about weathering and man’s impact on weathering itself—for better and for worse. Future computational, conceptual and methodological advances are set to cement weathering’s status as a central process in the Earth sciences.