Nat Keohane and I have been participating in the “Carbon Tax vs. Cap-and-Trade” debate over on Bulletin of the Atomic Scientists. From Round 3, which addresses the international aspects:
A cap-and-trade system allows for the creation of a global carbon market. Such a market would provide the mechanisms and flexibility necessary to achieve the environmental goals at the lowest cost and the incentives for other countries to join. A tax does neither, while requiring much more harmonization across countries.
This post is by Gernot Wagner, Ph.D., an economist in the Climate and Air program at Environmental Defense Fund.