This first chapter presents scientific knowledge validated by international journals—and thus by the scientific community—on the basis of rigorous criteria. One might wonder why such a presentation is necessary, when even without it, we surely know enough already about the state of the planet—enough to have reason to mobilize, to teach children and teenagers about the direction of the planet… or, indeed, to despair entirely. Obviously, the relationship with knowledge that we have today is no longer that which people had in the eighteenth century, which was marked by the Enlightenment’s struggle against ignorance; nor yet that of the nineteenth century, characterized by staggering proletarianization. In democratic nations, there are many ways of accessing scientific and academic knowledge—particularly via the Internet. However, a series of problems arise.