The Americans avoided any commitment to negotiate mandatory reductions in carbon dioxide emissions, something President Bush rejected in 2001 when he renounced the Kyoto Protocol, which requires rollbacks in other industrial nations by 2012.
On their side, the Europeans won a new forum for discussing just that ? a "seminar" next May at which governments can informally raise a range of climate issues, including next steps on emissions control after 2012.
"The only thing we want to discuss is future options, and we will," said a key EU negotiator, Pieter van Geel, the Dutch environment secretary.
If they do, U.S. diplomats are sure to ignore them. That was one reason other Europeans saw the Buenos Aires agreement as at best a small step to keep the multilateral process moving on climate change.
"It’s a finger-hold, like hanging on by your nails," said Michael Zammit Cutajar of Malta, a veteran climate negotiator.
The accord on the seminar was the chief outcome of a low-key, two-week annual conference on climate change, notable otherwise for its timing: on the eve of the final entry into force of the 1997 Kyoto pact next Feb. 16.
In 2001, when he rejected the Kyoto Protocol to the umbrella U.N. climate treaty, Bush said its pre-2012 emissions cuts would damage the U.S. economy, and he complained that China and other poor but industrializing countries were exempt under Kyoto. Here in Buenos Aires, the United States resisted efforts to design seminars in 2005 as forums to explore ways to control emissions after 2012.
"We think it is premature," U.S. delegation chief Paula Dobriansky, an undersecretary of state, said of the idea of post-Kyoto talks.
The Americans sought to focus attention he?e instead on long-range U.S. programs to develop cleaner-burning energy technologies ? not on immediate, mandatory emissions rollbacks.
Although they won no U.S. commitment to talk about reductions, the Europeans viewed the deal as a start, possibly to spur talks with developing nations, such as China and India, about post-2012 steps to help the climate.
Environmentalists and many delegates viewed the position of the United States, the world’s biggest emitter, as irresponsible.
"They’re trying everything possible to discredit any dialogue that would impact on certain economic interests," Tuvalu delegate Enele Sopoaga told a reporter, alluding to the oil and coal industries.
His Pacific nation of small scattered islands is already losing precious land to rising seas ? one consequence scientists predict from global warming.
Defending the Bush stance here on Wednesday, Dobriansky said the United States "believes that the best way to address climate change is through economic growth that at the same time preserves the environment."
The Kyoto Protocol itself requires member nations ? the United States not among them ? to open negotiations before 2006 on next steps after 2012. Environmentalists and delegates feared that if the Americans were not brought back into the process by next year ? under the umbrella treaty, not Kyoto ? the long-term brunt of fighting climate change would remain with the Europeans, Japan and Canada.
That, some worried, might eventually unravel even the fragmented global effort to put mandatory restraints on emissions.
Carbon dioxide, byproduct of automobile engines, power plants and other fossil fuel-burning industries, traps heat that otherwise would escape the atmosphere. A broad scientific consensus, endorsed by a U.N.-sponsored network of climatologists, holds that most of the past century’s global temperature rise ? 1 degree Fahrenheit ? was probably caused by the accumulation of greenhouse gases in the atmosphere.
Latest figures, for 2000, show that the United States accounted for 21 percent of the world’s emissions of carbon dioxide, methane and the handful of other problem gases, compared with 14 percent for the 25-nation European Union.
The Kyoto Protocol established a schedule of greenhouse-gas emissions for 30 industrial countries that ratified it. By 2012 the European Union, for example, must cut emissions by 8 percent below 1990 levels, and Japan by 6 percent.
As for the post-2012 period, expert studies suggest a "menu" of approaches to restraining emissions, particularly if poorer countries in various stages of development take on commitments.
The options might include firm caps and rollbacks for some, with voluntary targets for others; emissions quotas targeted at specific industries, such as electric-generation; acceptance of energy-efficiency standards; and more liberal "indexed" emissions targets that rise with economic growth.