Geoengineering – roughly the intentional technological manipulation of the earth’s environment on a global scale – is becoming a hot topic in climate change circles, as well as in the broader science and ethics communities. In this interdisciplinary seminar course, we will consider the science of geoengineering, and the ethical considerations at stake, including governance. We will concentrate on solar radiation management techniques, such as stratospheric sulfate injection, and marine cloud brightening. Scientifically, we will look at how such mechanisms affect the climate system, trajectories for research, and levels of uncertainty. Ethical topics will include emergency arguments for geoengineering, moral hazard, justice, political legitimacy, and ethical regulation of research and perhaps deployment. Versions of the course are cross-listed in Atmospheric Sciences, Environmental Studies and Philosophy. Entrance is via instructor permission only. Students outside the physical sciences should contact Steve Gardiner (at smgard@uw.edu). Students in physical science should contact Cecilia Bitz (at bitz@uw.edu).