Regional versus global cooperation for climate control

This paper considers whether international environmental public goods provision, such as mitigation of climate change, is better dealt with through regional cooperation than through a global treaty. Previous research suggests that, at best, a global environmental treaty will achieve very little. At worst, it will fail to enter into force. Using a simple dynamic game-theoretic model, with weakly renegotiation-proof equilibrium as solution concept, we demonstrate that two agreements can sustain a larger number of cooperating parties than a single global treaty. The model provides upper and lower bounds on the number of parties under each type of regime. It is shown that a regime with two agreements can Pareto dominate a regime based on a single global treaty. We conclude that regional cooperation might be a good alternative–or supplement–to global environmental agreements.