Global Warming Treaty Talks Bog Down : Environment: The participants strongly disagree over language to curb gases blamed for ‘greenhouse effect.’

Confronted with major disagreements over a global warming treaty, representatives of 140 nations Friday scheduled a final round of negotiations, hoping to resolve the problems in time to sign a treaty at a United Nations summit meeting in Rio de Janeiro in June.

But after five rounds of talks in a year, it appears increasingly likely that only a general framework for the treaty would be signed at the Rio meeting--at which 100 chiefs of state will meet to chart global environmental and economic development strategy for the next century. Provisions that would give the agreement clout are likely to require more years of negotiation.

Delegates agreed to return to the United Nations from April 30 to May 8 for a final attempt to hammer out the language of a pact designed to abate production of gases responsible for the “greenhouse effect,” a potentially dangerous warming of the Earth’s climate.

In the last two weeks, a working document was trimmed almost in half by eliminating language still in dispute. The major obstacle has been the United States’ refusal to go along with European insistence on stabilizing carbon dioxide emissions at 1990 levels by the year 2000.

Rather than accept such an objective, U.S. negotiators are holding out for an approach that focuses instead on control measures.

If carbon dioxide and other greenhouse gases continue to be produced at the present rate, the Earth’s climate could be warmed by three to eight degrees, with potentially devastating consequences, a landmark study sponsored by the United Nations concluded last year.

Some scientists continue to dispute the findings, however, contending that there is vast uncertainty over the impact of such climate change.

At the concluding session of the negotiations Friday, Nobel laureate Henry Kendall of Massachusetts Institute of Technology told delegates that carbon dioxide emissions should be reduced even more than has been proposed.

Speaking on behalf of about 40 environmental organizations around the world, Kendall, chairman of the Union of Concerned Scientists, said that a reduction of 60% is needed by the year 2025, “to lower the risk of unacceptable damage to natural ecosystems and humanity.”

While the Bush Administration contends that a drastic reduction in emissions would have enormous economic impact, Kendall said that a study by his environmental organization shows that cuts of 25% by 2005 and 70% by 2030 would mean “a net savings of over $2 trillion to U.S. energy consumers.”

The United States, which pledged $75 million Thursday to help developing nations study their greenhouse gas production and move toward controls, has promised to produce statistics on its own planned greenhouse gas reductions before the next negotiating session.

It listed dozens of steps already taken or planned by U.S. government and industry that would contribute to the abatement of greenhouse gas production.

Negotiations chairman Jean Ripert of France declined Friday to accept a characterization of the talks as deadlocked. He said that he will use the time between now and the resumed negotiations for talks with individual countries on the upcoming round.

Representatives of developing countries disagreed with the choice of the Global Environmental Facility as the instrument for managing aid to developing countries in the fight to limit greenhouse gas emissions.

Use of the U.N.-World Bank agency, said Gilbert Arum, an official of the Kenya Energy and Environment Organization, leaves to large industrial nations control of greenhouse pollution abatement measures in the developing world.