Reducing the costs of Copenhagen climate pledges in a post-Kyoto world

International audience; In current debates on a post-2012 global climate agreement, a key challenge is how to involve developing countries, in particular China, beyond the pledges they put forward after COP15 in Copenhagen. This article gives a macroeconomic assessment of different options for an extended Copenhagen pledges framework in order to alleviate the medium and long term costs of climate change mitigation. To do so, it uses a hybrid general equilibrium framework, in which suboptimalities are explicitly introduced. The results highlight that only an extending Copenhagen pledges with tradable permits of carbon emissions integrating non Annex 1 countries, as well as appropriate domestic accompanying measures may contribute to lowering the global costs to achieving the long term climate mitigation targets. It is also argued that articulating global and national policies can be an acceptable framework for China since it is aligned with its specific development priorities and offers the flexibility for domestic policies to support the transition. This mixed policy framework can be regarded as a reasonable first step towards a more ambitious global climate agreement on the long term.