Forest Lost is an ethnography of forest carbon offsets and the wider effort to make the living rainforest valuable in the Brazilian Amazon. Unlike other forest commodities, forest carbon offsets do not involve resource extraction; instead, they require keeping carbon in place through forest protection. Maron E. Greenleaf explores forest carbon offsets to understand green capitalism-the use of capitalist logics and practices to mitigate environmental damage. She traces cultural, environmental, governmental, material, and multispecies relations involved in making forest carbon valuable as well as how forest carbon’s commodification in the Amazon turned it into a source of redistributable public environmental wealth. At the same time, Greenleaf shows how making forest carbon monetarily valuable created an unexpected set of uneven, contingent, and contested social and political relations. While forest carbon in the Amazon demonstrates that green capitalism can be socially inclusive, it also shows that green capitalism can reinforce the marginalization it purportedly seeks to combat. By outlining these complex relations and tensions, Greenleaf elucidates broader efforts to create a capitalism suited to the Anthropocene and those efforts’ alluring promises and vexing failures.