Linking human evolution to environmental change is nearly as old as the concept of evolution. As soon as fossils of early humans were identified, questions were posed about how they fit into a story of changing vegetation and climate. Did human evolution occur amidst a backdrop of (or in part because of) expanding grasses and the development of hot, arid environments? Answering these questions rigorously requires many different types of data on a range of spatial and temporal scales. The collective communities of paleoanthropologists, paleontologists, archaeologists, geologists, ecologists, and climate scientists have made huge strides in addressing these questions in the past 25 years. Among the many data types used, the stable isotope composition of soil carbonates and mammal teeth has been a key resource for exploring the links between human evolution and environmental change. Soil carbonates and teeth have been so useful in part because the materials are abundant at most hominin sites and because the isotopic data from them can be readily aggregated to address landscape, ecosystem, and continental scale questions. In this talk I will showcase new datasets from fossil teeth and soil carbonate, including triple oxygen and clumped isotope datasets, that help refine our understanding of environmental change in eastern Africa and answer long-standing questions about the dynamics of temperature, aridity and vegetation.