This chapter explores the concept and practice of green regionalism in international economic law. It examines how economic agreements increasingly incorporate environmental protection measures through three key approaches: the liberalization of environmental goods and services, the regulation of subsidies, and the introduction of carbon tariffs. The chapter argues that these developments signify a significant shift toward integrating sustainability goals into the global trade regime, with regional and bilateral agreements serving as laboratories for innovative environmental provisions. While acknowledging that some approaches, particularly carbon tariffs, remain controversial, the chapter suggests that the trend of green regionalism may establish important precedents for future multilateral efforts to balance trade and environmental objectives and contribute to the Sustainable Development Goals.