With respect to the history of sciences under communism, we understand the gray zone to mean academic practices originating from the negotiated autonomy of academia and the need to respect scientific values such as objectivity and a critical approach to reality. Our research explores the links between academic communities that were not directly involved in dissident activities but actively supported dissent initiatives (very often for a limited period of time) and were linked to transnational scientific networks or social movements. Specifically, we analyze the involvement of socially engaged scientists employed by the official research institutions in dissident activities related to the environmental sciences.