Prospects for Paris 2015: do major emitters want the same climate ?

International negotiations have failed to achieve an ambitious outcome to limit climate risks. A Cournot outcome where countries determine their mitigation commitments in the full knowledge of those by others could be an important step. It would avoid a Stackelberg (leader-follower) outcome where one or more major emitters impose a level of climate risk on the rest of the world. This requires these countries to have sufficiently similar preferences over global cumulative emissions. We develop a novel stylised economic growth model to analyse the dynamics of international negotiations. Economies can be classified according to their committed emissions and the initial level of atmospheric CO2. We define a new metric, the desired mitigation effort, which provides an empirical methodology for comparing and evaluating countries’ mitigation commitments. A numerical calibration suggests a degree of convergence between the major emitters that might allow a Cournot-style agreement at the Paris Conference in 2015.