The political accord struck by leaders at the United Nations negotiations in Copenhagen in December 2009 allows participants to express their greenhouse gas commitments in a variety of ways. This paper compares the environmental and economic performance of these disparate commitments using the...

A central question in climate policy is whether early investments in low-carbon technologies are a useful first step towards a more effective climate agreement in the future. We introduce a climate cooperation model with endogenous R&D investments where countries protect their international...