High Risk, Low Reward: A Challenge to the Astronomical Value of Existential Risk Mitigation
David Thorstad
Abstract
Many philosophers defend two claims: the astronomical value thesis that it is\nastronomically important to mitigate existential risks to humanity, and existential risk\npessimism, the claim that humanity faces high levels of existential risk. It is natural to think\nthat existential risk pessimism supports the astronomical value thesis. In this paper, I argue\nthat precisely the opposite is true. Across a range of assumptions, existential risk\npessimism significantly reduces the value of existential risk mitigation, so much so that\npessimism threatens to falsify the astronomical value thesis. I argue that the best way to\nreconcile existential risk pessimism with the astronomical value thesis relies on a\nquestionable empirical assumption. I conclude by drawing out philosophical implications\nof this discussion, including a transformed understanding of the demandingness objection\nto consequentialism, reduced prospects for ethical longtermism, and a diminished moral\nimportance of existential risk mitigation.