Toby Svoboda

We thank the commentators for their interesting and helpful feedback on our previously published target article (Svoboda and Irvine, 2014). One of our objectives in that article was to identify areas of uncertainty that would need to be addressed in crafting a just SRM compensation system. The commentators have indicated some possible ways of reducing such uncertainty. Although we cannot respond to all their points due to limitations of space, we wish to address here the more pressing criticisms the commentators have offered.

Some authors have called for increased research on various forms of geoengineering as a means to address global climate change. This paper focuses on the question of whether a particular form of geoengineering, namely deploying sulfate aerosols in the stratosphere to counteract some of the effects of increased greenhouse gas concentrations, would be a just response to climate change. In particular, we examine problems sulfate aerosol geoengineering (SAG) faces in meeting the requirements of distributive, intergenerational, and procedural justice. We argue that SAG faces obstacles to meeting the requirements of all three considered kinds of justice, because its impacts can harm some persons and communities much more than others; it poses serious risks to future generations; and SAG is especially prone to unilateral implementation. While we do not claim that SAG ought not to be implemented, we argue that it is the responsibility of proponents of SAG to recognize and address these ethical obstacles before advocating its implementation.

The position of some environmental ethicists that some non-humans have intrinsic value as a mind-independent property is seriously flawed. This is because human beings lack any evidence for this position and hence are unjustified in holding it. For any possible world that is alleged to have this kind of intrinsic value, it is possible to conceive an observationally identical world that lacks intrinsic value. Hence, one is not justified in inferring the intrinsic value of some non-human from any set of observable properties, since that same set of properties could just as well exist in a world that lacks intrinsic value. However, since human beings do not have a faculty of intuition that would allow them to ..

As a response to climate change, geoengineering with solar radiation management has the potential to result in unjust harm. Potentially, this injustice could be ameliorated by providing compensation to victims of SRM. However, establishing a just SRM compensation system faces severe challenges. First, there is scientific uncertainty in detecting particular harmful impacts and causally attributing them to SRM. Second, there is ethical uncertainty regarding what principles should be used to determine responsibility and eligibility for compensation, as well as determining how much compensation ought to be paid. Significant challenges loom for crafting a just SRM compensation system

Although it could avoid some harmful effects of climate change, sulphate aerosol geoengineering (SAG), or injecting sulphate aerosols into the stratosphere in order to reflect incoming solar radiation, threatens substantial harm to humans and non-humans. I argue that SAG is prima facie ethically problematic from anthropocentric, animal liberationist, and biocentric perspectives. This might be taken to suggest that ethical evaluations of SAG can rely on Bryan Norton's convergence hypothesis, which predicts that anthropocentrists and non-anthropocentrists will agree to implement the same or similar environmental policies. However, there are potential scenarios in which anthropocentrists and non-anthropocentrists would seem to diverge on whether a particular SAG policy ought to be implemented. This suggests that the convergence hypothesis should not be relied on in ethical evaluation of SAG. Instead, ethicists should consider the merits and deficiencies of both non-anthropocentric perspectives and the ethical evaluations of SAG such perspectives afford

If deployed, aerosol geoengineering (AG) could involve unfairness to both present and future parties. I discuss three broad risks of unfairness that an AG deployment policy might carry: (1) causing disproportionate harm to those least responsible for climate change, (2) burdening future parties with the costs and risks of AG, and (3) excluding some interested parties from contributing to AG decision-making. Yet despite these risks, it may be too hasty to reject AG deployment as a potential climate change policy. I argue that since it is very unlikely that a completely fair climate change policy will be pursued, we have ethical reason to prefer some “incompletely fair” policy. Given various facts about our world, it might be the case that some AG policy is ethically preferable to many other feasible climate change policies, even if AG carries deeply problematic risks of unfairness.

According to the “Lesser of Two Evils Argument,” deployment of solar radiation management (SRM) geoengineering in a climate emergency would be morally justified because it likely would be the best option available. A prominent objection to this argument is that a climate emergency might constitute a genuine moral dilemma in which SRM would be impermissible even if it was the best option. However, while conceiving of a climate emergency as a moral dilemma accounts for some ethical concerns about SRM, it requires the controversial claim that there are genuine moral dilemmas, and it potentially undermines moral action guidance in emergency scenarios. Instead, it is better to conceive of climate emergencies as situations calling for agent-regret. This alternative allows us coherently to hold that SRM may be morally problematic even if it ought to be deployed in some scenario.