At this time of rapid global environmental change and demands for sweeping societal transformation, we call for greater scrutiny of the persistence of particular policies and ideas. In this Special Section we focus on REDD+, which for long has enjoyed remarkable global support in spite of poor outcomes and widespread criticisms. The central policy proposition of REDD+, that is, forest-based emissions reduction through market-based instruments and non-market means, are now carried forth under the new banner of Natural Climate Solutions. We examine REDD+ to understand how and why some environmental policies and ideas persist despite dubious impacts. We conceptualize policy persistence by drawing on three strands of political ecology literature - critical policy studies, assemblage studies, and political economy - that illuminate the dynamics of policy persistence in different yet complementary ways. We argue that the persistence of policies and policy ideas rests in a tentative balance of the counteracting processes of stabilization and contestation, which precipitate both intended and unintended outcomes. We show how the stabilization of REDD+ itself lends stability to broader ideas of forest-based climate change mitigation. We suggest that policy persistence is an area of political ecological research, which now calls for renewed engagement.