In Unfit for the Future, Ingmar Persson and Julian Savulescu present a challenging argument in favour of biomedical moral enhancement. In light of the existential threats of climate change, insufficient moral capacities of the human species seem to require a cautiously shaped programme of biomedical moral enhancement. The story of the tragedy of the commons creates the impression that climate catastrophe is unavoidable and consequently gives strength to the argument. The present paper analyses to what extent a policy in favour (...) of biomedical moral enhancement can thereby be justified and puts special emphasis on the political context. By reconstructing the theoretical assumptions of the argument and by taking them seriously, it is revealed that the argument is self-defeating. The tragedy of the commons may make moral enhancement appear necessary, but when it comes to its implementation, a second-order collective action-problem emerges and impedes the execution of the idea. The paper examines several modifications of the argument and shows how it can be based on easier enforceability of BME. While this implies enforcement, it is not an obstacle for the justification of BME. Rather, enforceability might be the decisive advantage of BME over other means. To take account of the global character of climate change, the paper closes with an inquiry of possible justifications of enforced BME on a global level. The upshot of the entire line of argumentation is that Unfit for the Future cannot justify BME because it ignores the nature of the problem of climate protection and political prerequisites of any solution. (shrink)