A Dynamic Mechanism for Transparent and Equitable Distribution of Global Emissions Reductions

With global attention focused on the 21st session of the Conference of Parties (COP21) in December 2015, much action is still needed and many obstacles remain unsolved in the international climate change negotiations: in particular, while the target of limiting global warming to below 2◦C relative to pre-industrial levels is widely cited in draft texts and discussions, little progress has been made in deciding how to align national contributions with such global emissions reduction aims. Building on a broad existing literature on distributing reduction contributions, this article proposes and analyzes an innovative new approach, based on a dynamic formula to determine Party-level targets through time. Addressing key requirements such as equity, transparency, environmental integrity and responsiveness to changing conditions, the resulting mechanism strongly encourages the convergence of per capita emissions trajectories across Parties, while maintaining overall global targets. The strengths of the approach are investigated and analysed through a number of detailed emissions simulations, comparing across growth scenarios and variations of the suggested formula. Concluding discussions describe the potential benefits of the new policy tool in the context of either voluntary pledges or top-down approaches and emissions trading schemes.