. . . this requires global greenhouse gas emissions to peak within the next 10 to 15 years, followed by substantial reductions of around 50 percent by 2050 compared to 1990s levels."

According to the sources, Abe told Bush during their April 27 meeting in the U.S. that Japan's proposal will involve developing technologies, creating low-carbon societies and taking other steps to halve emissions of carbon dioxide and other greenhouse gases by 2050.

Abe and Bush agreed that their countries can contribute to international efforts to fight global warming by employing energy-saving and other technological measures.

Tokyo has been working to beef up international efforts to fight global warming. During talks April 11 in Japan, Abe and Chinese Premier Wen Jiabao agreed to cooperate on creating an effective post-Kyoto Protocol framework from 2013.