US, allies want global pollution slashed _ by 2050

"This is a clear advance, compared with the shaky agreement from the previous year," said German Chancellor Angela Merkel.

Jim Connaughton, chairman of the White House Council on Environmental Quality, said, "It has always been the case that a long-term goal is one that must be shared."

"So what the G-8 has offered today is a G-8 view of what that goal could be and should be, but that can only occur with the agreement of all the other parties," he added, referring to nearly 200 countries involved in U.N. talks.

The agreement--and the praise it elicited among European countries usually more ambitious on climate change--reflected a desire to avoid shortcomings of the 1997 Kyoto accord.

Kyoto, while considered by many a worthy first step, has also been seen as flawed by its failure to commit developing countries like China to emissions controls, prompting the U.S. refusal to ratify it. In addition, many countries with reduction commitments, such as Japan and Canada, are falling seriously behind.