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 Thursday. 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 …