One of the most striking and often remarked upon effects of climate change is its power to unsettle our basic understanding of the modern world. Our planet is changing into a strange and unstable new environment, in a process seemingly outside technological control. The fossil fuels that once promised mastery over nature have turned out to be tools of destruction, disturbing the earth system. Even the recent past is no longer what we thought it was. Geologists are telling us that the whole territory of modern history, from the end of World War II to the present, forms the threshold to a new geological epoch: the Anthropocene. This dramatic discovery has aroused a great deal of interest far beyond the earth sciences. At the University of Chicago, a group of scholars are at the forefront of exploring the implications of the Anthropocene framework for historical research and the ways in which it encourages us to rethink our pedagogical aims. We are concerned with the history of planetary change in a double sense: the biophysical dimension of economic development in the context of the Anthropocene, and the history of earth system science, which produced this object of knowledge in the first place.