Laws need to be responsive and adaptive to the often-unforeseen changes in the marine environment, taking into consideration the marine ecosystem as a whole, and moving away from the traditional sectoral management. This may weaken the rule of law. Central to the legislative instruments in force regulating the use of aquatic systems and ocean management, is the concept of the ecosystem approach, which is extensively employed by instruments safeguarding marine ecosystems. This Chapter will consider implementation of the ecosystem approach in the overlapping legislative measures regulating ship source oil pollution in the Baltic Sea, a small intracontinental regional sea, which is one of the most polluted seas in the world. It will also consider how institutional interaction between these measures has affected implementation of the ecosystem approach in this regional multilayered regulatory system, and if that interaction will enable regional institutions as the key to successfully regulating international sectors such as shipping and strengthening the rule of law.

The chapter compares how the G20, the OECD and the IMF addressed fossil fuel subsidies and finds that while the three institutions agreed on the importance of reform of fossil fuel subsidies due to their environmental and economic consequences, they also differed in how they addressed these subsidies. Most notably, the IMF adopted a radical definition of fossil fuel subsidies based on the notion of corrective taxes, which stood out against the more established definition of the OECD. The chapter demonstrates that economisation may lead to diverging framings of the issue in economic terms. Subsequently, the chapter outlines how this divergence was driven by the differences in worldview, policy entrepreneurship and the degree of autonomy of the IO bureaucracy from principals. Yet, the similarities between their worldviews (they agreed on a range of fundamental issues), institutional interaction and overlapping memberships pulled in the direction of convergence between the institutions. Finally, there is a discussion on the consequences of this divergence at the international and domestic levels, while the convergence between the institutions was important for the attention to the issue and the norm of fossil fuel subsidy reform.

This chapter summarises the main findings of the book: international economic institutions address climate issues through economisation, yet there are differences in how exactly this economisation defines the issue at hand, differences mainly shaped by the institutional worldview of the institution and to lesser degrees by the relationship with member states. The differences were mitigated by the interaction between the institutions. The institutions were more influential regarding fossil fuel subsidies than regarding climate finance. This is due to fossil fuel subsidy reform resonating more with domestic actors than climate finance due to its positive fiscal impact (unlike climate finance that constitutes expenditure) and closer fit with neoclassical economics. These findings are discussed in the wider perspective of economic institutions and climate politics, arguing that economisation does not lead to a paradigm shift away from established practices of environmental politics. Furthermore, the economisation of climate finance and fossil fuel subsidy reform does not necessarily entail an overarching paradigm shift within the institutions, which continue with unsustainable practices such as political and economic support to fossil fuel production and consumption.

The OECD has a long institutional history of defining and providing knowledge about fossil fuel subsidies. While the G20 commitment to reform fossil fuel subsidies lifted OECD efforts to address fossil fuel subsidies to a new level, the institutional worldview of the OECD bureaucracy (influenced by the experience of addressing other kinds of subsidies) shaped how it was addressed. The OECD has been important in providing ideas, knowledge and possibilities for learning about fossil fuel subsidies among states, and influenced how the G20 and other international institutions addressed fossil fuel subsidies.

The 2009 G20 commitment to reform fossil fuel subsidies has proved to be a catalyst for the efforts to promote such reform. The chapter outlines the factors shaping this commitment as well as subsequent efforts to ensure that member states lived up to this commitment (the policy entrepreneurship of the US government, the G20 being an informal institution) and the consequences of the commitment on the international level. The commitment catalysed action in a range of other institutions including the World Bank, the OECD, the International Energy Agency and the Asia-Pacific Partnership) and the domestic level (in some states the commitment led to discussion of whether fossil fuels were subsidised or not).

All three institutions have framed climate finance in economic terms and stressed normative ideas such as efficiency. They have also linked climate finance to issues such as fossil fuel subsidies, carbon pricing, risk and investment to a larger degree than environmental institutions. Despite the overarching convergence between the institutions around addressing climate finance as an economic issue rather than an issue of environmental protection or global justice, the institutions also diverged on climate finance to some degree. The divergence is most notable regarding whether carbon pricing should constitute a source of climate finance, and to some extent also regarding how equity should be prioritised. Subsequently, this chapter explains this alignment in terms of economic worldviews and interaction pulling towards convergence. Divergence between the institutions has been driven less by fundamental differences in worldviews (e.g. between the OECD Development Directorate and the IMF) and the degree of autonomy from member states. Finally, the consequences of the output are described, identifying more significant (cognitive) influences at the international level than the domestic level, but also incentive-based influences from the OECD and the G20.

Given the regulatory gap in earth system governance, numerous new governance initiatives, such as multilateral clubs, private certification schemes and multi-stakeholder forums, have emerged to tackle transboundary environmental challenges. This plethora of different governance initiatives has led to a significant increase in the institutional complexity of global (environmental) policymaking and to more interlinkages between such institutions. Chapter 6 perceives dyadic institutional interlinkages as a key ‘microscopic’ structural feature of the overall global governance landscape and most basic building blocks or units of analysis in current scholarship on global governance architectures. After defining the term institutional interlinkages, we synthesize the literature on institutional interlinkages with a particular view on the expansion of interlinkages across different governance levels and scales. Against this backdrop, we examine to what extent the existing concepts and typologies of institutional interlinkages can capture the various new interlinkages between different kinds of institutions in earth system governance.