Unilateral Emissions Mitigation, Spillovers, and Global Learning

What’s the role of unilateral measures in global climate change mitigation in a post-Durban, post 2012 global policy regime? We argue that under conditions of preference heterogeneity, unilateral emissions mitigation at a subnational level may exist even when a nation is unwilling to commit to emission cuts. As the fraction of individuals unilaterally cutting emissions in a global strongly connected network of countries evolves over time, learning the costs of cutting emissions can result in the adoption of such activities globally and we establish that this will indeed happen under certain assumptions. We analyze the features of a policy proposal that could accelerate convergence to a low carbon world in the presence of global learning. JEL Classification: Q54, F53, Q55, O33. ∗We would like to thank participants ESRC funded Climate Change Workshops at Warwick (2009, 2010) and the CCCP-CAGE workshop "The Global Development Post-Durban Of Policy Regimes To Combat Climate Change" (March 2012) and two anonymous referees for their helpful comments. The third and the fourth authors acknowledge the support of the Ontario Research Fund. A companion paper "Unilateral measures and emissions mitigation" (2012) has a greater focus on documentation and policy while this paper focuses on the theoretical modelling of unilateral emissions mitigation and learning. E-mail addresses: [email protected]; [email protected]; [email protected]; [email protected]. 1