Governing complexity: How can the interplay of multilateral environmental agreements be harnessed for effective international market-based climate policy instruments?

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.