Prime Minister Shinzo Abe has proposed that the world set a common goal of halving greenhouse-gas emissions by 2050, but has not specified a baseline year. This approach is intended to gain the cooperation of both industrialized and developing countries to reduce their emissions in the post-Kyoto period. The proposal underscores Mr. Abe's desire for Japan to play a leading role in creating a new international framework to fight global warming beyond 2012, when the Kyoto Protocol expires.

Mr. Abe plans to have the Group of Eight countries reach a consensus at their June summit in Heiligendamm, Germany. This would allow them to compile a post-Kyoto action plan at the next G8 summit, which will be held in July 2008 at the Lake Toya resort area in Hokkaido. Under the 1997 Kyoto Protocol, industrialized countries are required to cut greenhouse-gas emissions by an average of 5.2 percent from 1990 levels. But the United States, the world's top polluter, has not ratified the agreement. China, the No. 2 polluter (and expected to soon surpass the U.S.), and India, No. 5, have no obligations to reduce their emissions because they are classified as developing countries.

In addition to not setting a base-line year, Mr. Abe has also sought to gain wide acceptance for his plan by saying that in creating the new framework due consideration will be given to the situation of every country. Germany, in contrast, has taken a tougher approach. It says global greenhouse-gas emissions should be cut to 50 percent below 1990 levels by 2050.