In this paper we will present the self-induced approach to decoherence, which does not require the interaction between the system and the environment: decoherence in closed quantum systems is possible. This fact has relevant consequences in cosmology, where the aim is to explain the emergence of classicality in the universe conceived as a closed (noninteracting) quantum system. In particular, we will show that the self-induced approach may be used for describing the evolution of a closed quantum universe, whose classical behavior arises as a result of decoherence.