Consequentialism seems to be ill equipped to deal with uncertainties and risks. Based on the underlying uncertainties, for consequentialists there seems to be no straight forward answer to the question of how to take possible consequences of geoengineering (GE) into account and how to compare them to possible consequences induced by climate change. While consequentialist seem to converge with most of normative theory that for now what we should do is to mitigate and adapt, and to consider geoengineering as nothing else then a last resort, easy answers of how to evaluate GE options in lesser evil situations vanish in the mist of uncertainty.
Many have turned their back on consequentialism and questions of lesser evil, outright condemning GE as hybris and focusing on the causes that may eventually lead to such lesser evil situations. Even though we find some of these accounts of foremost interest, we would like to take a different path and return to the issue of lesser evil situations from a consequentialist viewpoint.
To answer lesser evil questions in the case of GE from a consequentialist point of view, we need to develop a form multi-dimensional consequentialism, able to deal with uncertainties and the imposition of risks of harms. In the paper we will outline such a position and focus on stratospheric aerosol injection (SAI). As our argument will show, consequentialist do in fact face serious problems when it comes to navigating their way between possible (negative) outcomes. However, employing a multi-dimensional form of consequentialism which takes uncertainties and risks into the equation, allows us to carefully weigh different policy options without necessarily falling into the trap of short term thinking or subscribing to moral hazard. Thus, consequentialists have good reasons to support GE research efforts but to be sceptical of overly hasty SAI deployment.
