Talks Resume on Treaty to Avert Global Warming Threat : Environment: U.S. opposition to firm goals for reducing carbon dioxide emissions is a principal obstacle to any multinational agreement.

With time running out on them, representatives of governments around the world opened crucial negotiations at the United Nations on Tuesday on a treaty aimed at averting the threat of global warming.

Having made disappointing progress in four long rounds of talks on three continents, they were warned by the chairman of the U.N.-sponsored deliberations that they have about 100 hours of meeting time to reach compromises that have eluded them for more than a year.

The United States has been a principal obstacle, refusing to join European calls for a commitment to stabilize emissions of carbon dioxide at 1990 levels by the year 2000.

Produced by the combustion of fossil fuels--coal, oil, gasoline, wood--carbon dioxide is the principal “greenhouse gas” being pumped into the atmosphere. The United States is the leading producer, accounting for about 23% of the world total.

At the present rate of buildup, scientists have warned that carbon dioxide and other greenhouse gases could cause a potentially disastrous warming of the Earth’s climate--some 3 to 8 degrees--by the end of the next century.

As the sessions opened, there were hints that the Bush Administration might be preparing to soften its longstanding opposition to firm goals and timetables for reducing emissions.

Sources close to the deliberations said the U.S. position is under review by a team led by White House Chief of Staff Samuel K. Skinner, National Security Adviser Brent Scowcroft and Environmental Protection Agency Administrator William K. Reilly.

According to another source in the Administration, options under discussion include a possible per-capita limitation on carbon dioxide emissions, an approach that has been raised by the Japanese.

Top Administration officials are looking at forecasts of less robust U.S. economic growth, considering a long list of energy conservation possibilities and moving toward a conclusion that additional conservation measures could accomplish most of the stabilization of carbon dioxide production, sources said.

But there is no assumption among officials that the United States must shift its position before the current round of negotiations concludes on Feb. 28, the sources said.

Opening the fifth round of negotiations since January, 1991, French diplomat Jean Ripert, who has chaired all of the sessions, urged negotiators to make compromises, but “compromises without losing sight of the need for instruments for action and action now.”

Michael Zammit Cutujar of Malta, the executive secretary of the proceedings, told reporters the agreement must be completed by the end of April if it is to be signed as planned at a world environmental summit in Brazil in early June.

Regardless of the outcome of the current two-week session, officials expect to call a five-day or six-day wind-up session in April or May.

Negotiators also have been deadlocked on the other most important section of the proposed treaty--financing technology transfers and other assistance to developing countries.

Although the United States, Europe, Japan and the former Soviet Union have been the chief sources of carbon dioxide, future growth in emissions is expected to come from developing nations. The industrialized countries are seeking to find ways to help them limit carbon dioxide production without destroying their chances of economic growth.

So far, the delegates have not gotten to the point of even deciding whether the assistance should be managed by the United Nations Global Environmental Center or some entirely new machinery.

Most of the first week in the current negotiating round will be taken up by working groups seeking to resolve differences in a 130-page draft document left over from December negotiations in Geneva.

Environmental activists who have closely followed the negotiations from their beginning outside Washington last year said they were encouraged by the calls for decisive action in the next two weeks.

“Anyone who has been through these negotiations noticed a significant change in tone,” said Rafe Pomerance, a senior staffer of the World Resources Institute.

“Clearly the sense is that governments have to get down to business.”

The changed outlook, he said, is emerging in the U.S. government as well as in the international negotiating committee.

“The decision in the White House,” he said, “remains the single most important factor. It is clear now that debate in the Administration has produced options that would permit the United States to meet some targets and timetables.”

Although the key elements of a global warming agreement remain in contention, leaders of the negotiations say they expect a framework document to be ready for signing at the world environmental conference. More than 100 chiefs of state are expected to join thousands of government officials at the “Earth summit” in attempting to chart global environmental and economic development strategy for the 21st Century.

The question is whether that strategy will include binding commitments.

In his opening remarks calling for compromise, Ripert warned that “the need for urgent action will not be satisfied” by a mere framework convention. But he conceded that it would not be “illusory” to believe that protocols could be shaped in time for adoption at the June summit.

President Bush so far has given no indication as to whether he will join world leaders at the meeting.

But there are signs that the global warming issue may become a significant topic in campaign politics. In their last debate before Tuesday’s New Hampshire primary, all of the Democratic candidates called for the United States to join a commitment to stabilize carbon dioxide emissions at 1990 levels by the year 2000. They also urged Bush to go to Rio de Janiero to sign the convention in June.