Will the ambitious climate targets proposed at the G8 meeting in l’Aquila and discussed at COP15 in Copenhagen make the world more sustainable? In order to find an effective answer to this question, we should consider that a global climate policy may eventually lead to strong reductions of greenhouse gases, but it may also entail large costs and lower investments in education, wealth, or research and development. While the discussion on climate policy costs focus on GDP losses or monetary measures, authors introduce a new element in the discussion by combining economic, social, and environmental indicators onto a unique measure of sustainability, the FEEM Sustainability Index (FEEMSI), an innovative index which allows projecting sustainability indicators in the future. FEEMSI is able to summarize current and future sustainability performances for 40 countries up to the year 2020, and the effect of a stringent climate policy on sustainability is not straightforward
