Resources for the Future and the Institute for Global Environmental Strategies convened a oneand one-half day workshop on domestic and international climate policy May 11–12, 2005, in Tokyo,Japan. The first day included 49 participants hearing presentations from 13 speakers and discussingdomestic activities, economics, and politics. The second day included a smaller group of participantslistening to a panel of four experts and discussing opportunities for future international climate regimes.Participants included government officials from the Japanese Ministry of the Environment; the JapaneseMinistry of Economy, Trade and Industry; the U.S. Environmental Protection Agency; the U.S.Department of State; and the Massachussetts Department of Commonwealth Development;representatives from business and environmental groups; and academic experts. Over the course of bothdays, it was clear that great opportunities exist for regularly informing experts from both countries onrecent policy developments, economic analyses, and political nuances in the other country. For example,U.S. participants had an opportunity to learn the process through which Japanese technology standardsare set and implemented, the subtle evolution of mandatory policy discussions, and details of currentpolicies on voluntary trading and an emission registry. Japanese participants benefited from a frankdiscussion with U.S. experts of how and why it would be difficult to link different domestic emissionstrading markets, the current process to establish a regional emissions trading program, and the evolvingdynamics in the U.S. Senate.Looking forward, important lessons may be taken from past negotiating experiences. A smallgroup of national leaders, including large emitters of greenhouse gases and major economies, addressingnot only climate change but also developmental issues, could be a useful vehicle for meaningfulinternational efforts. Such a small-group process should be carried out in parallel with the multilateralUnited Nations Framework Convention on Climate Change process. In addition, policies in both theUnited States and Japan reflect a strong emphasis on technology development and commercialization; thismay be an area where bilateral cooperation could be particularly beneficial.