The UN's top climate official said the December 1-12 meeting of 10,700 delegates had started well as the half-way point in negotiations to agree a new climate treaty by the end of 2009 in Copenhagen. "I'm happy with where we are," Yvo de Boer, head of the UN Climate Change Secretariat, said of the meeting which will test governments' willingness to work on climate change amid a global economic slowdown.

Developing nations say they will need billions of dollars to help them combat warming and adapt to changes such as droughts, floods, more powerful cyclones and rising seas. Rich nations say they will help, but have made few pledges.

Several nations, including Democratic Republic of Congo, Suriname and Papua New Guinea, said rich nations had to help them safeguard tropical forests.

Trees soak up greenhouse gases as they grow, and burning forests to clear land for farming accounts for about 20 percent of warming from human activities. Governments want measures to slow deforestation as part of the 2009 deal.