Volcano engineering for food resiliency: uncertainty and ethics

Given that global catastrophic events – or disasters at the wrong pinch point - can threaten the interconnected and fragile global food system, the obvious approach is to reduce system vulnerability. One could also consider reducing exposure: it might be possible to reduce the probability or severity of some of the geophysical risks. I will discuss the possibility of volcano engineering, the deliberate altering of volcanic systems, in this case for reducing global food risk. Insofar this kind of reduction is possible, it raises both decision-theoretical and ethical questions. In terms of expected utility maximization reducing severe tail risks may sometimes dominate over reducing median risks, yet uncertainty (aleatory, model, and theoretical) will make any such dominance uncertain. Furthermore, such uncertainty will strongly affect the safety and rationality of the interventions themselves. Yet sufficient risk may still impel action. From an ethical standpoint, protecting large populations is a powerful reason for action but is similarly tempered by considerations of normative uncertainty, as well as justice, global governance, and our relationship with future generations. Given these considerations I analyse two scenarios where volcano engineering might hypothetically be used at some point in the future, a normal volcano near a global pinch-point like the Straits of Malacca, and a hotspot volcano with high VEI threatening global agriculture, and analyse under what technological, decision-theoretical, and ethical conditions interventions would be proper.