I am a geoscientist (geobiologist, biogeomagnetist, paleoclimatologist, and Earth historian) based in the Science, Technology, and Environmental Policy program and the Department of Geosciences at Princeton. My research is guided by the precepts that the present is a guide to the past, albeit an imperfect one, and the past is one of our best maps to the future. By studying the range of behaviors exhibited by Earth in the past, we can start to understand how the planet will respond to the newest geological force, human civilization.