The rise of climate-active municipalities – cities and towns voluntarily creating carbon reduction policy substantially more stringent than their host countries or the international system as a whole – presents a puzzle. Countries, with greater resources and the capacity to create binding agreements to overcome public goods problems, appear to view carbon reduction as an unappealing burden. So why are municipalities, with fewer resources and no way to guarantee a coordinated global effort, so eager to take on the potential disadvantages of stringent carbon reduction? Based on examination of municipal-level carbon reduction activity in Sweden and Portugal, I argue that in fact local-level climate activity represents not a burden but a tool. Municipal climate policy forms the basis for ‘paradiplomacy’ that captures goods for cities, creates international linkages for municipalities, and allows direct participation in setting the terms of global carbon commons policy. The evidence suggests that the nature of the climate commons – incompletely structured from a legal and political perspective, and open to access and intervention by actors at multiple levels – provides unique opportunities for actors to act as makers rather than takers of global governance structure and diplomatic effort in a critical area of emerging international policymaking.

气候活跃城市的兴起——城市和城镇自愿制定比东道国或整个国际体系更严格的碳减排政策——提出了一个难题。拥有更多资源和能力制定具有约束力的协议来克服公共产品问题的国家似乎将碳减排视为一种没有吸引力的负担。那么，为什么资源较少且无法保证全球协调一致的市政当局如此急于承担严格碳减排的潜在劣势呢？基于对瑞典和葡萄牙市政层面的碳减排活动的考察，我认为实际上地方层面的气候活动不是一种负担，而是一种工具。市政气候政策构成了为城市获取商品的“范式”的基础，为市政当局建立国际联系，并允许直接参与制定全球碳公共政策的条款。证据表明，气候公域的性质——从法律和政治角度不完整地构建，并且对行为者在多个层面的获取和干预开放——为行为者提供了独特的机会，使其成为全球治理结构和外交的制定者而不是接受者。在新兴国际决策的关键领域做出努力。