Scientific publications

Over the past decade, cooperative climate action has become a central feature of global climate governance. Thousands of businesses, subnational governments, civil society organizations, and international partnerships have mobilized to complement and support multilateral and state-led efforts. Using insights from the CoAct Database (formerly N-CID), and data from a sample of 387 initiatives, this chapter takes stock of developments since 2013 and looks ahead to how cooperative action can contribute to the implementation of the Paris Agreement, particularly addressing priorities arising from the Global Stocktake (GST). Our analysis yields five headline findings.

1. Rapid expansion, but uneven focus. CCIs have multiplied since 2015 and increasingly address adaptation, yet mitigation continues to dominate. While themes such as energy, land use, and industry remain strong, adaptation-related themes, e.g., particularly water, oceans, and resilience, remain underrepresented.

2. Effectiveness is improving, but equity gaps persist.

Many CCIs now deliver more tangible outputs and report more systematically, yet overall output effectiveness has plateaued since 2018. Smaller and less-resourced initiatives often lag behind due to capacity constraints, while limited accountability mechanisms—such as monitoring, transparent governance, and membership control—continue to hinder performance.

3. Participation has broadened, but inclusivity remains limited. Participation of actors in CCIs has expanded, but leadership and decision-making remain concentrated among Northern and institutional actors. Indigenous Peoples and Local Communities (IPLCs) are largely absent from governance structures, while engagement of businesses, investors, and local civil society has stagnated in recent years.

4. Stronger alignment with global priorities is needed. Future orchestration should strengthen coherence between CCIs and priorities in the implementation of the Paris Agreement, for instance those emerging from the Global Stocktake (GST). Integrating adaptation, nature, and resilience more effectively—and fostering synergies across thematic axes such as energy–nature, food–energy, and cities–ecosystems—can enhance the systemic impact of cooperative climate action.

5. The next five years are critical. To sustain momentum and credibility, CCIs and orchestrators, such as the High-Level Climate Champions, COP presidencies and the UNFCCC secretariat, must focus on inclusion, capacity, and accountability—especially in underrepresented regions. Expanding implementation and participation in low- and middle-income countries will improve both effectiveness and procedural justice. Deliberate orchestration by COP Presidencies, policymakers, and leading CCIs can ensure that cooperative climate action evolves toward greater balance, legitimacy, and transformative impact.

While cooperative climate action has expanded and matured over the past decade, its transformative potential remains only partly realized, calling for deeper structural and systemic change. As the world moves on to implement the Paris Agreement, cooperative initiatives should help accelerate ambition, bridge gaps in implementation, and foster more equitable and effective global climate action.

As COP30 approaches, policymakers must ensure that the integration of climate and biodiversity action by non-state and subnational actors is anchored in spatial data. Otherwise, we cannot see where change is happening, how effective it is, or who bears costs and benefits. The UNFCCC Global Climate Action and CBD Action Agenda Portals should lead by requiring spatial details on implementation, enabling more credible and participatory monitoring, analysis, and collaboration.

To contribute to Paris Agreement objectives, non-state actors globally are setting voluntary emission reduction goals. Cities represent an important group with emission reduction plans, but vary in how they intend to meet targets. Some cities incorporate carbon offsetting to manage residual emissions. A lack of research exists on the role of offsetting in city plans, and better understanding this approach can inform city climate policy. This study uses a mixed-method design to explore the frequency, characteristics and role of offsetting in city climate action. We quantify how many cities globally include offsetting in their plan, create a random forest model to explore what characteristics of cities and their targets are associated with offsetting, and conduct a text analysis of city documents to explore how cities that intend to use offsets conceptualize the use. We find 363 cities globally with a population over 500,000 have a numeric GHG reduction target; 86 of these include offsetting in their plan. Larger cities, those with a higher per capita GDP, and those with more ambitious climate targets are more likely to offset. Further, of 44 cities included in our text analysis that intend to use offsetting, 29 discuss prioritizing emissions reductions but recognize that offsets will be needed for residual emissions. Less than half the cities discuss environmental integrity of offsets, and many lack detail on how to ensure integrity. Specifying concrete plans regarding offsetting and communicating these decisions is important for effectiveness and integrity of city climate action plans, knowledge sharing between cities, and planning for future offsetting.

Many sector-level cooperative initiatives involving both national governments and non-state actors were launched around the 2021 Glasgow climate conference (COP26). However, there have been questions about whether and to what extent these initiatives could substantially contribute to achieving the Paris Agreement’s goal to limit global warming to 1.5 °C. To this end, this paper examines the prospects of the 14 Glasgow sector initiatives by investigating their aggregate mitigation ambition under current national signatories and the institutional robustness of each initiative. We find that the additional emission reduction ambition of the current national government signatories would, even if fully implemented, only fill about a quarter of the emissions gap in 2030 between the aggregate of existing national targets (nationally determined contributions: NDCs) and the required emission levels consistent with keeping warming below 1.5 °C, while the institutional robustness varied considerably across the initiatives. We also find that most national government signatories did not mention Glasgow initiatives in their updated NDCs submitted after COP26. Expansion of the national government participation, national government signatories’ incorporation of the initiatives’ goals into their updated NDCs by setting quantifiable domestic targets, and enhanced institutional capacity are key to successful emission reduction outcomes.