Urbanization is one of the major demographic and economic trends occurring in developing countries, with important consequences for development, energy use, and well being. Yet it is only beginning to be explicitly incorporated in long-term scenario analyses of energy and emissions. We assess...

Learning – i.e. the acquisition of new information that leads to changes in our assessment of uncertainty – plays a prominent role in the international climate policy debate. For example, the view that we should postpone actions until we know more continues to be influential. The latest work...

Multi-gas approaches to climate change policies require a metric establishing ?equivalences? among emissions of various species. Climate scientists and economists have proposed four classes of such metrics and debated their relative merits. We present a unifying framework that clarifies the...