Climate risks have always been amongst the most important faced by human societies. Today the concern has new elements: the global nature of possible changes and the fact that they are driven by human activity. The risks posed by climate change are therefore endogenous and so outside of the...

We review the optimal pattern of carbon emission abatements across countries in a simple multi-country world. We model explicitly the fact that the atmosphere is a public good. Within this framework we establish conditions for it to be necessary for optimality that the marginal cost of abatement...