Environmentalists criticized the United States and other rich countries Tuesday for failing so far to make meaningful commitments at a U.N. conference on climate change.

Some 190 countries are meeting in Poznan, Poland, for talks that are part of the attempt to reach a new climate-change treaty in the Danish capital of Copenhagen next year.

But activists warned of failure at the Poznan talks, which last through Dec. 12, saying industrialized countries are resisting setting long-term targets for cutting the emission of greenhouse gases unless developing countries make a similar sacrifice.

"We were quite disappointed in the negotiations that went on" because negotiators were "splitting hairs" on whether to adopt long-term goals to reduce emissions, said Savio Carvalho of Oxfam International.

"We are discussing now if we should even reach these targets, and that's alarming," he said.

Carvalho said there was a general lack of trust between the developed and developing world at the talks. He called on the U.S., Japan, Australia and New Zealand to agree to policies that would lessen their dependence on fossil fuels and urged them to share technology with the developing world to help those nations do the same.

However, he praised Brazil, which he said has "been progressive and has been pushing the boundaries."

Brazil announced plans Monday to significantly slow the destruction of the Amazon rain forest by 2017. Scientists say that would reduce global warming by slashing the amount of carbon dioxide emitted when trees are burned.

A goal of the Poznan talks is to produce a "shared vision" on 2050 targets on greenhouse gas emissions, to guide negotiations leading to the critical Copenhagen conference next December.

But Alden Meyer of the Union of Concerned Scientists said he doesn't believe a shared vision will emerge in Poznan because the Bush administration "refuses to put any target on the table for 2020."

Meyer said wealthy industrial countries need to slash emissions, transfer green technology to developing countries and provide funding to help them adapt now to the climate changes already under way, such as rising sea levels and harsher weather patterns.

"That's the shared vision," Meyer said. "The reason we can't get it is because the Bush administration has refused to put on the table any meaningful target and any meaningful financial package from the U.S."

Meyer said until a U.S. president is "willing to talk about doing that, you're not going to get consensus in this hall on a shared vision."

President-elect Barack Obama — who has vowed to make the United States a global leader on the environment — will be inaugurated Jan. 20, replacing President George W. Bush.

Harlan Watson, the chief U.S. delegate, said Monday he expected no agreement on specific global targets for emissions cuts by 2020 at Poznan.