Who benefits from the US withdrawal of the Kyoto Protocol? An application of the MMEA method to measure power

Since 1992, the international community is trying to arrive at a multilateral agreement on the reduction of emissions for greenhouse gases. A collective decision mechanism was adopted in 1997: An agreement is ratified if and only if it is approved by a coalition gathering more than 55 countries. Moreover, the ratifying industrialized countries - included in the Annex I of the Kyoto Protocol - must represent a total weight corresponding to at least 55% of the total CO2 emissions of the countries of the Annex I, taking the year 1990 as a reference point.One way to study the theoretical power distribution induced by this voting procedure is to compute the Banzhaf index for each country. Firstly, the results of the computation show that the power distribution is largely heterogeneous and benefits to the United-States. Secondly, we analyze the modifications generated by the European coalition scenario in order to prove that the European strategy to act as a single block counterbalanced the US leadership. Finally, we conclude that Japan and Russia benefited from the United States withdrawal in term of a priori decisional power.