Catalysing Change? The Role and Contributions of Cooperative Climate Initiatives in Decarbonisation Efforts

Cooperative Climate Initiatives (CCIs) are increasingly recognised as critical governance arrangements enabling more ambitious and effective climate action by nonstate and subnational actors, bridging governance gaps left by insufficient national efforts. The potential contributions of these voluntary, transnational and multistakeholder partnerships to decarbonisation efforts are often assessed through either large-N quantitative analyses based on databases that map CCI activity, or individual, in-depth case studies on specific initiatives. However, a critical gap remains insofar as large-N studies rarely provide generalisable causal explanations on how CCIs drive action by individual actors. In contrast, case studies lack scalability across diverse contexts. This literature review addresses this gap by synthesising case study evidence on CCI contributions to decarbonisation, focusing on causal mechanisms —such as norm diffusion and learning processes— that drive the scaling and entrenchment of climate policies. By contrasting the diverse outcomes and impacts of initiatives, the study provides insights into whether and how CCIs reinforce unsustainable systems, provide incremental reforms, or catalyse more transformative action. Results are contrasted to large-N quantitative mappings of CCI effectiveness, as well as insights from polycentric and multilevel governance, institutional complexity, and meta-governance theories that emphasise the role of networked governance arrangements, such as CCIs, in the ever more fragmented global response to climate change. The review places specific attention on post-Paris impacts under initiatives orchestrated within the multilateral climate regime, namely transnational city networks and private sector initiatives led by or closely collaborating with the UNFCCC and other international governmental organisations targeting climate action.