Action-oriented summits like the 2018 Global Climate Action Summit and 2019 UN Climate Action Summit, have become a major feature of global climate governance. Their emphasis on cooperative initiatives by a host of non-state and local actors creates high expectations, especially when, according to the IPCC, governments’ policies still set the world on course for a disastrous 2.7 °C warming. While earlier studies have cautioned against undue optimism, empirical evidence on summits and their ability to leverage transnational capacities has been scarce. Here using a dataset of 276 climate initiatives we show important differences in output performance, with no improvement among initiatives associated with more recent summits. A summit’s focus on certain themes and an emphasis on minimal requirements for institutional robustness, however, can positively influence the effectiveness of transnational engagement. These results make an empirical contribution towards understanding the increasingly transnational nature of climate governance.

2018年全球气候行动峰会、2019年联合国气候行动峰会等行动型峰会已成为全球气候治理的一大特色。他们对许多非国家和地方行为者的合作举措的强调引起了很高的期望，尤其是当根据 IPCC 的说法，政府的政策仍然让世界走上灾难性的 2.7°C 变暖的轨道。虽然早期的研究告诫人们不要过度乐观，但关于峰会及其利用跨国能力的能力的经验证据却很少。在这里，使用 276 项气候倡议的数据集，我们显示了产出绩效的重要差异，与最近的峰会相关的倡议没有改善。然而，峰会关注某些主题并强调对制度稳健性的最低要求，可以对跨国参与的有效性产生积极影响。这些结果对理解气候治理日益跨国的性质做出了实证贡献。