UNITED NATIONS, June 27: Trying to silence worldwide criticism, the United States pledged on Thursday to help bridle dangerous global warming but refused to give European allies the specific action what they really want.

A day after approving historic limits on smog and soot, President Clinton was addressing the United Nations Earth Summit to warn about the menace of toxic emissions.

The science on this issue is clear and compelling: humans are changing our climate,'' Kathleen McGinty, a top environmental aide, told reporters in a preview of the evening address.

The European Union proposes cutting greenhouse gases -- carbondioxide, methane and nitrous oxide by 15 per cent below 1990 levels, with a deadline of 2010. Under pressure from corporate lobbyists and a skeptical Congress, the President has refused to commit to targets before December's global warming treaty negotiations in Kyoto, Japan.

``McGinty said the EU's 15 per cent goal is impossible to reach,'' but she offered no alternative target. Clinton will talk to American leaders in science and business before setting a US goal, she said. The US-European split soured an otherwise amicable gathering of world leaders in Denver last week. And in the days leading up to Clinton's speech, allies criticized administration policy from the UN floor drawing razor-edged reaction from the White House.

Hoping to defuse tensions, Clinton moved more quickly than planned to announce on Wednesday that he would back tighter pollution limits on soot and smog. Though the environmental protection agency rules do not speak directly to global warming, White House aides hoped the action would convince allies that Clinton has the backbone to stand up to big industry and Congress.

The President wants legally binding emission-reduction goals that apply to developing nations. He also wants the targets to be flexible so countries can implement them as cheaply as possible.

In Washington, Clinton's stand against targets gained support from house speaker Newt Gingrich and John Howard, the visiting Prime Minister of Australia. While the President keeps his negotiating options open, corporate America is mounting an aggressive lobbying campaign to argue that curbing emissions would curb profits and cost tens of thousands of jobs.

The weeklong summit, dubbed Earth Summit plus 5,'' was designed to review progress since the Earth summit in Rio De Janeiro in 1992. AP

Copyright © 1997 Indian Express Newspapers (Bombay) Ltd.