Effective and stable international climate accords.

The objective of this thesis is to identify the fundamental drivers of welfare effectiveness and game theoretic stability of International Environmental Agreements (IEAs), while focusing in particular on heterogeneity of regions; and analyzing the distributional effects of different climate change damage channels and mitigation policies. In the first phase we apply an analytical model combined with numerical simulation experiments in order to derive hypotheses regarding the impact of heterogeneity of players on stability and effectiveness of coalitions. In the second phase we turn to a more realistic model, an integrated assessment model, and test the hypotheses statistically on a big dataset of simulation results. Overall, our results show that the impact is often non-monotonic, it also depends on the considered stability concept and specification of climate change damages.

We use the integrated assessment model also to study the distributional effects of different climate change damage channels and mitigation policies in the global cooperation. We have found that poor and rich regions are affected differently by climate change under different assumptions about damage channels. Also, results show that there exists a strong tradeoff between equity and efficiency in the design of welfare maximizing global climate policy and that transfers between regions or permit trade can moderate this tradeoff.