This article examines the conditions under which environmental activism emerged and evolved in Brazil from 1970 e 2006. The idea was to introduce a conceptual discussion on the relations between "opportunity structures", "political processes", and "individual involvement" in the emergence of mobilizations and collective protests. The methodology consisted of biographical interviews with three different generations of activists, focusing on the meanings associated with the use of academic training in activism, the principal modalities of militant careers, and the types of resources and social ties that support the activists' concepts and practices. The research showed that the period under study constitutes a milestone for the emergence of new patterns for reconverting university and professional training into militant resources for action in the "environmental field".
opportunity structures; political processes; individual involvement; activism; environmentalism