Combining efficiency with equity : a pragmatic approach

What is at stake in the climate negotiations is the provision of a global public good, indeed a "clean" atmosphere.The Kyoto Protocol is only a very minor step toward this objective. Looking further ahead in time, beyond the 2008-2012 period, Annex I Parties' commitments will not be sufficient to achieve the goal of a "clean atmosphere". The question is then how to define a second commitment period agreement with a view to contribute to the ultimate provision of a "clean atmosphere"?The central issue is that of equity, in a context of conflict of interests, where all the countries do not contribute to GHG emissions for the same amount and do not share the same interest in climate mitigation efforts. In addition, in a world of scarce resources, it is clear that most countries will try to achieve any emissions limitation objective at the lowest possible cost.Our paper addresses the two inter-related issues of equity and cost-efficiency: we examine the conditions in which the developing countries could contribute to the effort of reducing global GHG emissions, on the basis of quantified emissions objectives, in addition to the mitigation actions taken by the industrialized countries. The underlying question is: how to allocate GHG emissions allowances to all the countries of the world in an equitable and efficient way ?