OSLO, (Reuters) – Aid of $10 billion from rich  nations would be a “good beginning” to launch a U.N. climate  treaty due to be agreed in Copenhagen in December, the United  Nations’ top climate official said yesterday.

Yvo de Boer, head of the U.N. Climate Change Secretariat,  also told the BBC World Service in an interview that rich  countries needed to pledge deep cuts in greenhouse gas emissions  by 2020 and the poor had to slow the rise in their emissions.

But cash was needed to kick-start a deal.

“If we can get in Copenhagen something like 10 billion euros  or dollars on the table that will allow developing countries to  begin preparing national plans to limit their emissions and  adapt to climate change, then that would be a good beginning,”  he said.

“But even more importantly, Copenhagen has to agree an  architecture, a burden-sharing formula, that will allow us to  share out the costs of climate action among countries as the  needs increase over time,” he added.

Costs of fighting climate change in the longer term could be  up to $200 billion a year, according to U.N. projections.

Developing nations say the rich have to show willingness to  give cash to launch a new U.N pact to succeed the U.N.’s Kyoto  Protocol beyond 2012.
Many developing nations are likely to be hardest hit by  climate change such as more droughts, disease, floods, heat  waves and rising sea levels.

De Boer said that rich nations were finding it harder to  come up with cash because of the recession. “It’s become more  difficult to raise financial resources,” he said.

He also said developed countries should be guided in  planning emissions cuts by what he has often called a “good  beacon” of reductions of 25 to 40 percent below 1990 levels by  2020.