Geologic evidence suggests significant increases in uplift rates and absolute elevation in several areas during the late Cenozoic, especially in the last 10 m.y. Regions of major uplift include the Tibetan Plateau and Himalayan Mountains of southern Asia; and the Sierra Nevada, Colorado Plateau, Basin and Range, Rocky Mountains, and High Plains of the American west. Uplift occurred at a scale large enough to affect regional and global climate in a number of ways, several of which we evaluate by General Circulation Model experiments in accompanying papers. ¿ American Geophysical Union 1989