Prime Minister Shinzo Abe on Thursday announced a new greenhouse gas initiative calling for emissions to be halved worldwide by 2050 from current levels.

The proposal, made during a speech to Asian leaders titled "Invitation to Cool Earth 50," appears designed to help Japan take the lead in international efforts to come up with a post-Kyoto Protocol plan to combat global warming when it hosts the Group of Eight summit in July 2008.

"I propose that the world share the long-term target of halving worldwide emissions by 2050 from the current levels," Abe said in the speech. "We first need to share the target globally, since the current global emissions are more than double the amount that can be absorbed by the nature."