International climate law is often represented as a set of rules and institutions that scholars have tracked for nearly 30 years, whether to document them, assess their effectiveness, or prescribe reforms. This article, in contrast, adopts a critical perspective to uncover the everyday life of international climate law. From this viewpoint, international climate law is a purposive endeavour that is grounded in the small places where people create and live out the law. ‘International climate lawyers’ are among those who produce the law within these sites, and they propagate international climate law across multiple institutions. Using legal-ethnographic description, the article shows how lawyers operationalize the law in the United Nations climate regime, World Bank, and international human rights system. In each case, lawyers effect some overlapping aspirations for the law as well as legal techniques, but they also adapt their practices to the places where they work. In the process, they simultaneously build and diversify their professional community. Both in their field and community then, lawyers generate heterogeneity and homogeneity through the proliferation of international climate law. They do so on multiple registers, in terms of diverging ethical commitments, multivalent legal forms, and relative authority to speak the law, notably between institutions and the Global North and Global South. If lawyers reproduce sameness and difference in international climate law, moreover, this article suggests they may reify analogous traits in the broader field of international law, including persisting power relations.