THE irony was evident to all: On the first day of the international conference on global warming in Berlin, an unseasonal snowstorm blanketed the host city.
The snow that fell March 28 has long since melted, but disputes between rich and poor nations still seem frozen in place. Experts from more than 130 nations haggled for eight days, sometimes through the night, but they could not agree on how -- or whether -- to lower the planet's temperature.
On Wednesday, environment ministers and other top elected officials converged on Berlin for the meeting's final stage. They hoped to salvage some kind of agreement before today's closing session.
The Berlin conference, the follow-up to the 1992 environmental summit in Rio de Janeiro, has focused on ways to reduce production of ''greenhouse gases,'' including carbon dioxide (CO2), which many scientists say contribute to warming.
The goal had been to agree on CO2-reduction targets after the year 2000. But such an agreement appears unlikely: Arguments between rich and poor nations over how to cut back on CO2, and which nations should take responsibility for the task, have prevented most concrete decisions from being taken.
But at least one citizens group says there is a simpler way to help the environment.
''We should plant trees,'' says Karl Peter Hasenkamp, president of Prima Klima, a small German nonprofit environmental group based in Dusseldorf. ''Trees are probably the most cost-effective way to reduce CO2.''
In the global warming debate, industrialized nations have tended to concentrate on making sources of CO2 emissions -- such as power plants and autos -- more efficient. More attention should be given to methods that remove CO2 from the atmosphere, not just reduce the rate of emissions, Mr. Hasenkamp says.
One tree produces enough oxygen daily to allow four people to breathe, while consuming 26 pounds of CO2 annually, Hasenkamp says. A typical household in an industrialized nation produces up to 50 metric tons of CO2 a year, he adds.
Hasenkamp hasn't dallied in translating his concern about global warming into action. Prima Klima, which he founded in 1991, has contributed to tree-planting projects on five continents -- including two in Germany, three in the United States and one each in South Africa, Vietnam, Ecuador, Hungary, and Ukraine. So far the projects have been limited in scale -- with only about two square miles of trees planted -- mainly because of the difficulty in finding funding.
Governments are hindering his efforts with their apparent lack of interest in promoting tree planting, Hasenkamp says. ''Unfortunately, the politicians have come to admire big technical solutions to problems. Ministers enjoy being photographed cutting a ribbon or pressing a button,'' he says.
In addition, he added, industrialized nations like Germany consider environmentally friendly technology as a potentially lucrative export item. ''Growing trees doesn't offer the same profit potential,'' Hasenkamp says.
As for the climate conference, some participants say the United Nations, which sponsored the gathering, brought on some of the gridlock itself. The UN did a poor job in planning the conference, scheduling it too close to the UN social summit held in early March in Copenhagen, said Atiq Rahman of the Bangladesh Center for Advanced Studies.
''Someone should have given more thought to timing. People are tired of these meetings,'' Mr. Rahman says. ''This is the typical UN at work, where the right hand doesn't know what the left is doing.''