Chapter 4 analyses processes of making climate mitigation into a policy area during the 1970s to mid 1990s. It explores the ideas, frames, and interests that informed United Nations climate change debates, how mitigation came to be defined as a policy area, and, ultimately, the specific compromises that were necessary to agree emissions reduction targets for Annex 1 countries. The role of political compromise in processes of reaching agreements and on governing bodies is foregrounded. Particular attention is also paid to questions of how pro-mitigation groups articulated the need for change, the role of climate science within this, how anti-mitigation coalitions narrated their contestations, and how these debates informed compromises reached. Although negotiated outcomes were unsatisfactory in many ways, there is a sense that all parties did, to greater or lesser extents, compromise to engender these first stages in the politicisation of climate mitigation.

Chapter 5 is about processes of making mitigation policy choices, largely in Annex 1 countries, from the immediate post-Kyoto period up to 2008. Although there had been some debate about difficulties in reducing emissions in the pre-Kyoto period, it was during this following phase that more clarity emerged about the choices and contestations policymakers faced in practice and the institutions that shaped them. These ranged from deciding where mitigation decisions should be taken, in existing or new departments or ministries; what the overall approach should be and what types of policy should be preferred; to how reducing emissions relates to objectives in other policy areas and what to do about perceived trade-offs. The politics of making collective mitigation choices, and how those choices were influenced, started to become more tangible, whilst climate mitigation was subject to a range of politicisations in a deliberative sense.