Major new multilateral environmental agreements (MEAs) have entered into force in 2016, including the Paris Agreement (PA) under the United Nations Framework Convention on Climate Change (UNFCCC) with nationally determined contributions (NDCs) for greenhouse gas (GHG) reduction, the Kigali Amendment (KA) to the Montreal Protocol with a phase-down schedule for HFC production and use in all countries as well as the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) under the International Civil Aviation Organization, an offset mechanism for GHG emissions. Regarding climate change mitigation, these MEAs are implicitly and explicitly linked to each other. However, the interaction effects between them have not yet been studied. We apply document analysis to assess the following question: how does the MEA interplay impact the scope and effectiveness of international market-based climate policy instruments defined in Article 6 of the PA (Paris Mechanisms) regarding NDC achievement? The Paris Mechanisms can generate early reductions in HFCs that lower the KA baseline and thus the entire phase-down schedule, thereby generating long-term GHG mitigation. Reduction in HFC-23—a large, controversial source of carbon credits under the Kyoto Protocol’s Clean Development Mechanism (CDM)—is now mandated through the KA and thus no longer available for international market mechanisms. If it accepts CDM credits predating 2020, CORSIA will not generate demand for emission units generated by the Article 6 mechanisms and thus not impact their effectiveness. Otherwise, CORSIA demand for Article 6 credits enhances effectiveness, provided that ‘double counting’ of credits is prevented through corresponding adjustments.

中文翻译：

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治理复杂性：如何利用多边环境协定的相互作用来制定有效的基于市场的国际气候政策工具？

主要的新多边环境协定 (MEA) 已于 2016 年生效，包括《联合国气候变化框架公约》(UNFCCC) 下的《巴黎协定》(PA)，其中包含减少温室气体 (GHG) 的国家自主贡献 (NDC)、蒙特利尔议定书的基加利修正案 (KA)，包括逐步减少所有国家 HFC 生产和使用的时间表，以及国际民用航空组织下的国际航空碳抵消和减少计划 (CORSIA)，这是一种温室气体抵消机制排放。关于减缓气候变化，这些多边环境协定相互隐含和明确地联系在一起。然而，尚未研究它们之间的相互作用。我们应用文档分析来评估以下问题：MEA 的相互作用如何影响 PA（巴黎机制）第 6 条中定义的关于 NDC 实现的基于市场的国际气候政策工具的范围和有效性？巴黎机制可以尽早减少 HFC，从而降低 KA 基线，从而降低整个逐步减少计划，从而产生长期的温室气体减排。HFC-23 是京都议定书清洁发展机制 (CDM) 下的一个大的、有争议的碳信用来源，现在已通过 KA 强制要求减少，因此不再适用于国际市场机制。如果在 2020 年之前接受 CDM 信用，CORSIA 将不会产生对第 6 条机制产生的排放单位的需求，因此不会影响其有效性。否则，CORSIA 对第 6 条信用的要求会提高有效性，