After the previous chapter outlined the current state of research on global climate governance and identified a substantial gap in the literature, this chapter describes the theoretical background and analytical framework of the book. I start with a general definition and conceptualization of the term ‘authority’ and continue with a thorough discussion of relevant theoretical approaches to the concept of authority. Next, I present the research design for the empirical analysis. In particular, I specify the project’s primary research question and formulate three conceptual assumptions about the relationship between transnational climate initiatives and the international climate regime. And then, I introduce the case studies and briefly refer to the methods of data collection.