International political economy of climate negotiations and consideration of mitigation and adaptation costs.

Summary This thesis deals with cooperation and climate governance in the post-Copenhagen era. Its objective is to characterize the evolution of the climate regime, based on the positions of the European Union, China and the United States, which can be designated as large emitters, major economies and great powers. Two determinants are considered structuring for this analysis: the costs of mitigation and the costs of adaptation. The starting point of our thesis is the polarized evolution of the climate regime. The most significant fact of this "metamorphosis" is the shift, in 2009, from a top-down to a bottom-up approach.To do so, we mobilize a hybrid theoretical framework, which includes International Political Economy and the Economics of Climate Change. The combined contribution of these two approaches allows us to analyze international climate policy through environmental economics and conversely, to inform the impact that these relationships can have on economic logic. We propose a specific approach to cooperation based on Duncan Snidal's (1985) "k-group" theory.Within this minilateral cooperative framework, the thesis we argue is that it is possible to have a k-group for climate and that it can have a beneficial effect on climate regime development. We argue that this group can be considered a "club of the relevant" and that, in order to form a k-group, it is necessary for countries to form a "coalition of the willing". What structures the capacity and willingness to act are primarily the costs involved, both mitigation and adaptation costs. At the same time, the commitment of this group is based on conditioning. The incentive device is the idea of increasingly broad cooperation, which mitigates the free rider problem.The research results are appreciated in light of the outcome of COP 21. If the k-group works, it is because the three countries decide to move forward and agree to shoulder greater mitigation costs than other countries. This collective commitment would trigger a virtuous movement that would impose shared leadership on the climate regime among these three countries, paving the way for the others. If the k-group does not work, it is because our actors consider the short-term costs too high in relation to their own interests and in relation to the risk of free riding by other states. Given the economic situation in which our three actors find themselves, this scenario appears to be probable.Finally, in our model of the analysis of cooperation, we favor the Europe-China tandem. We show that this tripartite cooperation should be built from this pair, since, unlike the United States, it is Europe that appears to be more willing. China, the key player in the climate field, which is likely to suffer the full consequences of climate change, has more interest in joining Europe if it wishes to obtain an agreement that is not based solely on minimum (national) contributions.