Why do firms that present low levels of (direct) carbon emissions participate in “carbon clubs”, which have the goal of managing and reducing greenhouse gas (GHG) emissions? In order to answer this question, we collected data from both primary and secondary sources from firms operating in the Brazilian banking sector, which are members of the Businesses for Climate Platform (Plataforma Empresas pelo Clima – EPC). We first looked for answers in the institutional theory and resource based view of the firm (RBV). By confronting the arguments presented by these streams of scientific enquiry with empirical data, we worked on theory testing. In particular, we analyzed the institutional pressures and resources and capabilities of the focus companies, in order to understand the rationales for proactive sustainability management. We found evidences of the arguments presented by both the institutional theory and the RBV. By studying an industry that is not a frequent subject to research on socio-environmental issues – for not being considered of high impact – in an emerging market economy, the research contributes to both the further development of the institutional theory and the advancement of sustainability management in corporations.