To deal effectively with transboundary environmental problems such as climate change, it is important to have an idea of the model for an "efficient" and "fair" policy. An understanding of the strategic interactions involved in the international decision-making process is also essential. In this volume Carsten Helm uses rigorous theoretical reasoning and applications to address these issues. The first part of the book contains a normative analysis based on fair division theory and welfare theory. The empirical focus is on burden sharing in the climate change regime, for which a concrete proposal is derived. The book then extends the perspective by taking into account the self-interest of sovereign states. Using co-operative game theory the potential for Pareto efficient co-operation is analyzed. Finally, Carsten Helm applies non-cooperative game theory to analyze issues such as environmental and welfare effects of emissions trading, the misuse of scientific uncertainties as a bargaining tool and the effects of discontinuities in environmental systems on co-operation.