This paper resumes a previous discussion on Environmental Ethics and Irreversibility, which was presented in 2005. There I first faced the problem. Now I would like to reevaluate the issue. Was my paper “catastrophist”? Or was it, instead, realistic? Which are today the main issues confronting Environmental Ethics? Plainly speaking, what can we really do? These are some of the questions I would like to bring in to the debate with my colleagues and the public. In other words, instead of focusing in the aspect of “irreversibility”, I prefer here to focus on the “responsibility” of agents and institutions. It rescues the so-called “Principle of Responsibility”, by Hans Jonas. There is also some debate with Karl-Otto Appel and Habermas. If, on one hand, there are irreversible damages to nature, as the extinction of species and even of natural locations, as rivers and other natural accidents, there are, on the other hand, many actions that can and must be taken in order to preserve or deter the grave consequences of the environmental degradation. In this paper, I try to discuss some of the problems and propose some solutions, but the more important thing is to call everyone – individuals, groups, or institutions – to responsibility face the Earth, the Human and not-human beings, and mainly the future generations.