1 Data Envelopment Analysis of Different Climate Policy Scenarios by

Recent developments in the political, scientific and economic debate on climate change suggest that it is of critical importance to develop new approaches able to compare policy scenarios while also taking their performance in terms of the sustainability paradigm into account. This paper discusses a quantitative methodology to assess the relative performance of different climate policy scenarios when accounting for their long-term economic, social and environmental impacts. The proposed procedure is based on Data Envelopment Analysis, here employed in evaluating relative efficiency of ten global climate scenarios. The methodology provides a promising comparison framework; it can be seen as a way of setting some basic guidelines to frame further debates and negotiations and can be flexibly adopted and modified by decision makers to obtain information relevant for policy design. In the present paper, we find that the “do nothing ” strategy is inevitably dominated either by moderate or by stringent policies, depending on how much the policy-maker values environmental and social impacts in addition to policy costs. More generally, scenarios that would not pass the economic efficiency test might reveal a good performance in terms of sustainability notwithstanding their relatively high costs