Human activities are central to the debate on global environmental changes, constituted as unprecedented challenges to contemporary societies in transition to the Anthropocene. Regarding social and political dimensions of global environmental changes and the perspective of risk society, this article analyses how Brazil and China are politically responding to these challenges. It provides a summary of the main events and trends of environmental policies in Brazil and China, two countries that have been noted for their international importance and, above all, for the importance of environmental issues at the core of their actual political processes. From a theoretical point of view, an intercrossed analysis capable of fostering dialogue between environmental sociology, social theory and sustainability is proposed, considering international relations and the notion of governance. For both countries, the question that remains is whether the actions proposed and the existing political and institutional structures are sufficient to respond effectively to contemporary environmental risks, mainly in time to prevent irreversible climate change.