We cannot be justified in believing that any actions currently available to us will have a non-negligible positive influence on the billion-plus-year future. I offer three arguments for this thesis. According to the Infinite Washout Argument, standard decision-theoretic calculation schemes fail if there is no temporal discounting of the consequences we are willing to consider. Given the non-zero chance that the effects of your actions will produce infinitely many unpredictable bad and good effects, any finite effects will be washed out in expectation by those infinitudes. According to the Cluelessness Argument, we cannot justifiably guess what actions, among those currently available to us, are relatively more or less likely to have positive effects after a billion years. We cannot be justified, for example, in thinking that nuclear war or human extinction would be more likely to have bad than good consequences in a billion years. According to the Negligibility Argument, even if we could justifiably guess that some particular action is likelier to have good than bad consequences in a billion years, the odds of good consequences would be negligibly tiny due to the compounding of probabilities over time.