The scientific community, almost unanimously, agrees on these points: 1) the conditions of the planet are decidedly degraded to the point of endangering all living species, including mankind; 2) the degrees of this degradation, primarily climate change, are already out of control and are very close to the point of no return; and 3) it is now accepted that this situation is imputable to human behavior. This paper questions what man can do in this circumstance, keeping in mind his condition as an animal, his rationality, and the possibility of choice.