Russia Takes Step Toward Approval of Kyoto Protocol

"Sadly, this leaves the U.S. isolated in its refusal to join the international effort to reduce greenhouse gas pollution," said Fred Krupp, president of Environmental Defense.

Although congressional advocates of action to address global warming have said it is unrealistic to expect U.S. approval of the Kyoto accord, two senators said Thursday that the United States must address its emission problems. Sens. John McCain (R-Ariz.) and Joe Lieberman (D-Conn.) propose a modified system of caps to enforce improved U.S. standards. A version of their bill was opposed by President Bush and failed in a Senate vote last year.

"As a world leader, the United States cannot afford to stand on the sidelines as the global campaign to curb global warming gains steam and more and more of our competitors gain the advantage in adapting to this environmental and economic reality," Lieberman said.

Times staff writers Paul Richter and Elizabeth Shogren in Washington and special correspondent Alexei V. Kuznetsov in Moscow contributed to this report.