Most climate change opinion leaders on both sides of the Atlantic have modest expectations for the July Summit in Hokkaido, Japan. On the central political question-how quickly Europe, the United States, and other G8 partners should reduce emissions over the next decade-the transatlantic allies appear an ocean apart. Outside the United States, most G8 policymakers seem content to run out the clock on the Bush administration with the goal of finding common ground with a new, more climate-friendly U.S. President in 2009.

Downplaying the Hokkaido G8 summit could be a serious mistake. While G8 nations are unlikely to reach an agreement this year on ambitious quantitative medium-term emission reduction targets, much could be done now to lock-in sound architectural elements or legal frameworks for numerical commitments that could be negotiated next year or soon after. Specifically, the G8 should agree that all major emitters should take on legally binding but differentiated emission mitigation commitments, with developed countries agreeing to fixed national emission targets and developing countries selecting from a broader menu of nationally appropriate options. By agreeing to this now, G8 leaders could add momentum to global climate negotiations, increase the odds of concluding a new climate pact next year and, importantly, significantly improve the prospects that the United States would participate in the new agreement.