This article examines the work of a group of scientists who contributed to influential climate policy approaches while taking part in groundbreaking research on climate transformations. The scientists promoted a policy approach known as REDD+, which was designed to slow climate change by paying forest landholders to not cut their forests. These scientists also made important contributions to the science of the Anthropocene, which is premised on the idea that humanity has become a geological force that is transforming the planet in disruptive ways. I argue that their science and policy efforts are at odds with anthropological critiques that view environmentalists as experts who see themselves as bearing exceptional “cultural” capacities and therefore as capable of protecting or improving “Nature.” In a region of Amazonia, the science of the Anthropocene and the associated REDD+ projects moved beyond ontological understandings that divide the world into the opposing spheres of Nature and Culture. The scientists did not see themselves as inhabiting a “cultural” sphere from which they could protect Amazonia as a “natural” object, but rather they used REDD+ projects to immerse themselves in what they felt were irreversible, uncontrollable, and disruptive socioenvironmental transformations.