Human extinction risk and uncertainty: Assessing conditions for action

Under what sets of conditions ought humanity undertake actions to reduce the risk of human extinction? Though many agree that the risk of human extinction is high and intolerable, there is little research into the actions society ought to undertake if one or more methods for estimating human extinction risk indicate that the acceptable threshold is exceeded. In addition to presenting a set of patterns of lower and upper probabilities that describe human extinction risks over 1000 years, the paper presents a framework for philosophical perspectives about obligations to future generations and the actions society might undertake. The framework for philosophical perspectives links three perspectives-no regrets, fairness, maintain options-with the action framework. The framework for action details the six levels of actions societies could take to reduce the human extinction risk, ranging from doing nothing (Level I) to moving to an extreme war footing in which economies are organized around reducing human extinction risk (Level VI). The paper concludes with an assessment of the actions that could be taken to reduce human extinction risk given various patterns of upper and lower human extinction risk probabilities, the three philosophical perspectives, and the six categories of actions.