The Conference of the Parties (COP) under the UNFCCC is a key forum for global climate action, combining high-level negotiations with participation from non-state actors. Subnational governments engage through paradiplomacy, using side events and collaborations to advocate for stronger climate policies and influence policy results. The COP is a crucial global forum for addressing climate change, bringing together nearly 200 nations under the United Nations Framework Convention on Climate Change (UNFCCC). Since its inception in 1995, COP has served as a platform for countries to assess progress, share strategies, and negotiate commitments to reduce emissions and combat climate change. COP functions through a combination of high-level plenaries, where overarching decisions are debated and adopted, technical negotiations in smaller working groups, and where delegates craft detailed final agreements.
As the climate crisis deepens, COPs have become a governance stage, also serving as a hub for non-state actors participating in side events, exhibitions, and informal consultations. Increasingly, the international activities of subnational governments (i.e., regional and local governments) – conceptualized as paradiplomacy – have emerged as vital to these discussions. By participating in COPs, they put forward concrete paradiplomacy actions to influence global (climate) policy outcomes.
A Conceptual Framework of Analysis
Although subnational actors are not part of formal COP negotiations, they still play an important role in influencing global climate policies by promoting and demanding more substantial climate commitments (i.e., advocacy). To explain how such reality occurs, we highlight the specific paradiplomacy instruments (i.e., public policy tools to engage in international activities) through which regions and cities participate in global forums like climate COPs. According to recent literature, subnational actors may represent themselves in such international gatherings via intra-state/extra-state routes. For clarity, intra-state routes involve being represented within the federal or central government’s delegation at the COP. In contrast, extra-state routes refer to subnational governments autonomously sending their delegation to participate in non-official side events and strategic meetings, as will be further explained.
Second, by engaging in international activities via different paradiplomacy strategies, either intra-state or extra-state routes, regional and local entities intend to raise awareness of climate issues and showcase their local initiatives via non-official interactions throughout the COP to increase their influence. These paradiplomacy interactions take place in two main ways: (1) collectively, by engaging in networks with other regions, cities, and organizations, which helps amplify their voices and advocate for more substantial climate commitments, and (2) individually, by (2.1.) engaging within their central government’s delegation or by (2.2.) autonomously engaging with other stakeholders in the COP process to highlighting their own interests either. Collectively, subnational governments participate in networks’ side events such as workshops, panels, and gatherings to emphasize their collective efforts. Individually, they collaborate with their national state to align policies and influence the national positioning during negotiation or autonomously engage in strategic meetings with counterparts like international organizations, civil society groups, and NGOs, as well as dialogues with other cities and regions to develop shared climate strategies and future partnerships.
By bridging paradiplomacy strategies with the type of paradiplomacy interactions, we notice that these are interrelated and define the type of engagement of different subnational governments during COPs. Paradiplomacy instruments—intra-state routes and extra-state routes—are by subnational governments to engage in international activities. These instruments differ in terms of how subnational governments interact within or beyond the framework of their national governments (see Table 1).
Strategies and interaction are interrelated, representing complementary approaches for subnational actors to enhance their influence. Intra-state routes leverage national representation to align interests, while extra-state routes expand their outreach through individual and collaborative efforts. While corresponding to different paradiplomacy and respective modo interactions, these are not exclusive, and regions and cities may adopt different combinations. Together, they highlight the multifaceted ways subnational governments participate in global climate governance.
They do this by raising awareness of climate issues and showcasing their local initiatives via non-official interactions throughout the COP. These paradiplomacy interactions take place in two main ways: (1) collectively, by participating in networks with other regions, cities, and organizations, which helps amplify their voices and advocate for more substantial climate commitments, and (2) individually, by engaging directly with other stakeholders in the COP process to highlight their interests. Collectively, subnational governments participate in networks’ side events such as workshops, panels, and gatherings to emphasize their collective efforts. Individually, they collaborate with their national state to align policies or autonomously engage in strategic meetings with counterparts like international organizations, civil society groups, and NGOs, as well as dialogues with other cities and regions to develop shared climate strategies.
Intra-state routes: Individual Modes of Interactions
When adopting intra-state routes as part of their paradiplomacy strategies, subnational governments act through their inclusion in the federal or national delegation to advocate for their priorities. In these cases, subnational actors participate in the COP process under the umbrella of their national government, using the delegation as a platform to represent their interests and influence global climate discussions.
During COPs, individual interactions under intra-state routes often manifest in strategy meetings and consultations between subnational and national representatives. For instance, subnational actors may meet with federal negotiators to provide updates on local progress, propose regional solutions, or advocate for greater ambition in national climate commitments. Beyond internal meetings, they may also serve as advisors or contributors within the broader national delegation, participating in panels, technical workshops, or policy briefings on behalf of their government. In the case of Canada, for instance, the provinces of British Columbia and Ontario have continuously joined the Canadian delegation from 1992 up to 2021 (as the most up-to-date sources). Similarly, the President of the Zagreb City Assembly participated in COP29 as a speaker focusing on National Adaptation Plans (NAPs) and local authorities’ contributions in shaping them. The discussion will emphasize the critical role of cities and regions in addressing local adaptation needs and aligning them with broader national adaptation strategies. The city of Glasgow provides another illustration, the host of COP26, which worked with the Scottish and UK governments to align its urban climate strategies with national energy efficiency targets, evidencing that cities can serve as platforms for advancing national goals in urban contexts.
By embedding themselves in the national delegation, subnational governments leveraging intra-state routes can magnify their influence and ensure that their perspectives shape the overarching climate policies their countries present on the global stage.
Extra-state Routes: Collective and Individual Modes of Interactions
As mentioned, when endorsing extra-state routes as part of their paradiplomacy strategy, subnational entitiesoperate as actors representing their own position. Through their delegation, regions and cities may choose to participate in COP using collective and individual interactions, most of the time taking the opportunity to endorse both modes to increase their chances of influence.
Collective interaction takes place through collaborative platforms called transnational networks. According to the literature, these are described as informal cross-border interactions involving at least one non-state actor or an entity not representing a national government or intergovernmental organization. By interacting through such collaborative platforms, each delegation of subnational governments integrates a united front emphasizing ambitious policies and sharing innovative solutions for tackling climate change. Prominent examples of networks include the Regions4 or the C40 Cities Climate Leadership Group or the under2Coalition, which unite jurisdictions committed to decisive climate action, often surpassing national government pledges. By collaborating and presenting a united front, these subnational governments influence climate dialogue, emphasizing the significance of ambitious policies and sharing successful strategies for tackling climate change.
Outside COPs, networks facilitate knowledge-sharing and collective initiatives regarding climate policy. Nevertheless, during COPs, they organize insider activities to share best practices among participants, such as workshops, panels, and roundtable discussions where subnational leaders and experts discuss specific climate topics, share best practices, and showcase successful initiatives. Recent examples include the panels organized by Regions4 during COP28 and COP29, the Local Climate Action Summit (LCAS) during COP28, and the Under2 Coalition General Assembly, which occurred alongside COP29 in Baku. Besides these activities, there are opportunities to connect and form partnerships between networks and other stakeholders to demonstrate collaborative commitments and emphasize collective ambition. A clear expression of such activity concerns the C40 partnership and NUS Cities at COP29 focused on urban climate resilience.
Additionally, policy briefings are also a result of collective interactions. The latter intends to inform decision-makers about the importance of subnational action while advocating for higher commitments, such as the letter endorsed by mayors, governors, and subnational leaders under C40 and the Regions4 Progress Report 2024 published during COP29. Through a single collective voice, the interaction of subnational actors via networks creates momentum and encourages negotiating parties to adopt more ambitious policies.
On the other hand, individual interaction within extra-state routes occurs through direct engagement by delegations of subnational governments with a variety of state and non-state actors present in the COP, which include international organizations, states, NGOs, private sector representatives, and other subnational entities. These interactions are characterized by independent efforts to promote their delegation’s policies, initiatives, and commitments to addressing climate change. By acting autonomously, subnational delegations showcase their unique contributions, foster tailored partnerships, and position themselves as influential actors in global climate governance.
In this case, activities include discussions with the different stakeholders regarding diverse topics (emissions reduction, climate finance, renewable energies, green economy, among others), such as strategic meetings to advocate bilateral and multilateral collaborations and partnerships with international organizations, civil society, and non-governmental organizations (NGOs) but also dialogues with other cities and regions to foster future collaborations on shared climate strategies.
A proactive illustration of such practice in bilateral terms was expressed by California during COP23, expressing its intent to keep close dialogues with the EU on the design and implementation of carbon markets during COP23. During COP28, California’s delegation has also launched two new international climate multilateral partnerships and joining one: The Subnational Methane Action Coalition (a partnership of subnational governments that are committed to reducing methane), the Mediterranean Climate Action Partnership (Statement of Commitment to establish the Mediterranean Climate Action Partnership); and the Global Offshore Wind Alliance (a coalition aiming to generate 380 gigawatts (GW) of offshore wind energy by 2030, aligning with California’s own renewable energy goals). During this same, COP Québec’s delegation, Lithium Universe, and Investissement Québec have also engaged in strategic dialogues for using green hydroelectric power from Hydro-Québec for the eco-friendly lithium refinery hub, which will produce 16,000 tons of battery-grade lithium carbonate annually which will boost North America’s supply. More recent examples are the Malaysian Johor state and Japan’s Saitama city, which signed a memorandum of bilateral cooperation during COP29 on the sustainable use of wood.
The Conference of the Parties (COP) under the UNFCCC has evolved into a critical platform where subnational governments actively influence global climate policies through paradiplomacy. Despite lacking formal representation, subnational governments play a crucial role at the Conference of the Parties (COP), actively engaging in the evolving global climate governance framework. By engaging via intra-state and extra-state routes, regions and cities help bridge the gap between local needs and global commitments, aligning grassroots innovation with international strategies. These actions enhance climate governance by amplifying diverse perspectives, fostering more inclusive solutions, and ensuring local realities inform global decisions within the COP.
Contributions from regional and local authorities enrich the global dialogue, fostering more representative decision-making processes. Moreover, showcasing local successes at COP encourages the replication of effective strategies, stimulates partnerships, and strengthens collective ambition. By integrating these perspectives, COP becomes more than a venue for high-level negotiations—it transforms into a dynamic space where collaboration across governance levels accelerates the transition to sustainable and climate-resilient futures. This multidimensional approach, combining global commitments with local action, is indispensable for addressing the urgent and complex climate crisis challenges.
Table 1. Paradiplomacy Instruments and Modes of Interaction during COPs.
Acknowledgements: This work has received support from the Research Center in Political Science, University of Minho, through national funding from the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Education and Science under grant UIDB/CPO/00758/2020.
Further Reading on E-International Relations