This chapter discusses what a more thoroughly globalized environmental sociology might look like, and the need to re-think more deeply the ways in which we conceptualize environmental sociology. Five challenges are discussed: i) the need to better understand globalization itself and the emergence of new sources and forms of authority; ii) the socially uneven causes and impacts of global environmental problems and injustices; iii) the task of democratizing science by asking whose voices are missing and whose knowledge counts in the understanding of global environmental matters; iv) the need for a more cosmopolitan environmental sociology that is sensitive both to local particularities and to shared concerns at the national and transnational levels; and v) the question of how environmental sociology might contribute to debate about possible and desirable global futures. The chapter concludes by arguing that responding to these challenges and engaging productively with other disciplines requires a sociology that unsettles boundaries between the social and natural sciences and partipates on equal terms in the production of environmental knowledge.