Environmental Ethics and the Presumptive Argument against Geoengineering
Christopher Preston
The University of Montana
The rapid rise in interest in schemes to geoengineer the climate as a response to anthropogenic
global warming presents a clear and significant challenge to environmental ethics. After a brief
introduction to the two main types of geoengineering, this paper articulates what it calls the
“presumptive argument” against geoengineering from environmental ethics, a presumption
strong enough to make geoengineering almost “unthinkable” from within that tradition. Two
rationales for suspending that presumption are then considered. One of them focuses on a “lesser
evil” argument, the other on connections to ecofacism and the anthropocentrism/nonanthropocentrism debate. The discussion draws attention to the question of how environmental
ethicists should orient themselves to geoengineering and what they should think about the moral
significance of natural, large-scale biogeochemical processes.