Accord climatique. Concessions et ratifications

We consider a bargaining game aiming at the full ratification of a climate treaty. Three distinct coalitions are considered: a pro-regime coalition, the so-called Kyoto group, an anti-regime coalition made of the countries rejecting the Kyoto protocol and the G77 coalition made of developing countries. We assume that the pro-regime coalition wants to ratify the treaty as such while the two other coalitions condition ratification to further concessions. Employing an alternating offers model, we study the concession the pro-regime coalition should make for the others to accept ratify the treaty. We show that the more binding is the ratification constraint of the pro-regime coalition, the lowest is the concession. Conversely, the more binding the ratification constraints of the two adverse coalitions, the highest should be the concession. Classification JEL : C78, D72, D74, Q53.