Abstract Developing countries are growing apart on environmental issues. International environmental negotiations are no longer characterized merely by the North–South conflict. Rising powers have come to divide the Global South and redefine the Common-But-Differentiated Responsibilities principle. This article explains the divergence of China and India at the Kigali Amendment to the Montreal Protocol, one of the first global environmental agreements to differentiate obligations between developing countries. China and India, the world’s two largest hydrofluorocarbon producers, ended decades of collaboration and split the rest of the developing world behind them. I argue that developmental strategy and political institutions shape the preferences and influences of industrial, governmental, and social stakeholders, thereby explaining their negotiation behavior and outcome. This article explains why China moved faster and further than India on negotiations for hydrofluorocarbon regulation. It has important implications for the two rising powers’ implementation of the Kigali Amendment and for their position formulations on other environmental issues.