"It's moving pretty well now," Yvo de Boer, head of the U.N. Climate Change Secretariat, told reporters of the Aug. 21-27 talks which are defining the building blocks of a new U.N. global warming pact meant to be agreed by the end of 2009.

"We're getting beyond some of the rhetoric," he said of the 160-nation meeting among about 1,500 delegates. "People are beginning to understand each other better."

The Accra meeting is the third session this year under a plan to agree a broad new climate treaty by the end of 2009 to succeed the Kyoto Protocol, which sets greenhouse gas targets for just 37 developed nations.

Accra is focusing largely on ways to encourage tropical developing nations to slow the rate of deforestation and debating whether industries such as steel, aluminium or cement should have international benchmarks for efficiency.

"The Accra meeting has been very successful so far," said Luiz Figueiredo Machado, a Brazilian expert chairing talks on new ways for countries ranging from the United States to China to curb emissions.

Accra is not meant to end with any firm agreements.

Many delegates left the last session, in Germany in June, saying the talks were lagging in an assault on climate change that could drive more species to extinction, bring more desertification, floods, heatwaves and rising seas.

TREES

"The chances that it (a new U.N. scheme to slow deforestation) will go ahead, in my mind, are much higher," Machado told Reuters. He said that there was an "overwhelming consensus" on the importance of the project.

Trees soak up carbon dioxide, the main greenhouse gas, as they grow and release it when they are burnt, often by poor farmers clearing land for farming. U.N. data suggests it accounts for 20 percent of greenhouse gases from human sources.

Cash to slow deforestation is widely seen as an incentive to get poor nations to start slowing their rising emissions of greenhouse gases, mainly from burning fossil fuels.

Emily Brickell, forest campaigner with the WWF environmental group, said it might cost between $20 to $30 billion a year to set up a system to safeguard tropical forests, perhaps using a mixture of carbon markets or donor funds.

The talks are also seeking to bridge differences over whether to impose sectoral targets for industries, an idea championed this year by Japan.

Some developing nations, smarting from the collapse of world trade talks last month, fear such benchmarks could be a backdoor way to impose trade barriers on their less efficient producers of metals or cement.

But Japan clearly stated during the talks that it did not favour imposing common international standards. "What I saw and heard in our debates on sectoral actions and approaches was a very fruitful debate," Machado said. "It clarified the issue."