A 160-nation U.N. climate conference in Ghana split on Friday over ways to pay poor countries to slow deforestation, blamed for producing up to 20 percent of the greenhouse gases caused by human activities.
Options suggested for raising billions of dollars in incentives include markets that would allow trading in the carbon dioxide locked up in trees, higher aid from rich nations and levies on airline tickets or on international shipping.
"It's important that we get to grips with this," Yvo de Boer, head of the U.N. Climate Change Secretariat, told Reuters during the Aug. 21-27 meeting of 1,500 delegates.
"For many developing countries, avoiding deforestation is pretty much the only way they can engage in the climate change regime and reap some benefits," he said of schemes meant to slow logging and burning of forests to clear land for farming.
A U.N. climate conference in Bali last year agreed to explore ways to pay people in the developing world to leave forests standing -- trees soak up carbon dioxide as they grow and release it when they rot or are burned.
The Accra meeting is working on details as part of a plan to agree a sweeping new U.N. climate treaty by the end of 2009 to avert heatwaves, droughts, more powerful storms, risks of more disease and rising sea levels.
"We think this is particularly relevant to Africa. We want this next climate regime to benefit Africa," said Brice Lalonde of France, speaking on behalf of the European Union. France holds the rotating EU presidency.
He said the EU was willing to consider extra aid or to work out new forms of carbon trading. The European parliament voted this year to auction 15 percent of emissions from aviation and use proceeds for measures such as slowing deforestation.
"We shall perhaps see a new dawn for tropical forests," Lalonde said.
The Pacific island of Tuvalu, threatened by rising seas, said a levy of $20 a tonne on emissions of carbon dioxide from all international aviation and maritime transport would generate revenues of about $24 billion a year.
"A levy of that level is about 0.6 percent of an airfare price," said Ian Fry of Tuvalu. Slowing economic growth in many nations, along with high food and fuel prices, makes it harder to find cash for forest protection.
Friends of the Earth said there were risks that an inflow of funds would push up the value of forests and lead to a land grab by foreign investors that could threaten the rights of indigenous peoples on the land.
But some developing nations said partnerships with business were inevitable.
"This is about rural communities and indigenous peoples. This is about business. We have got to bring communities and the private sector together," said Kevin Conrad of Papua New Guinea, speaking on behalf of about 20 tropical nations.
De Boer played down worries about "carbon colonialism", saying that measures to protect forests seemed to be in the interests of local people who were dependent on the range of species of animals and plants found in forests.