Yvo de Boer tells the BBC that we should bring $10 billion in cash and a 25 to 40 percent reduction in CO2 emissions to the table in Copenhagen; if Brazil, India, and China then “[offer] national actions that will significantly take their emissions below business as usual,” they can gather up their sacks of cash.

And that will be a success.

The UN’s top climate official has said that the richest nations will have to put $10bn “on the table” during the Copenhagen climate change summit.
Yvo De Boer, who will lead the negotiations, said such a commitment was necessary for their success.
He insisted the burden of climate change must be shared and that the money would help developing countries.
Leading nations participating in the summit must, he said, sign an agreement to reduce greenhouse gas emissions.
Mr De Boer, head of the United Nations Framework Convention on Climate Change (UNFCCC), said the $10bn (£6bn) pledge would be “a good beginning”.
“(It) will allow developing countries to begin preparing national plans to limit their own emissions, and to adapt to climate change,” he told the BBC World Service’s One Planet programme.
Mr De Boer was less keen to put an exact figure on the levels of emission cuts the biggest economies should commit to.
Some scientists have called for a 25-40% reduction by 2020 — a proposal he describes as “a good beacon to be working towards”.
As well as the hard cash and paper pledge from developed nations, success at Copenhagen will come from one other factor, he revealed.
“If on that piece of paper, China, India, Brazil and other major developing countries have offered national actions, that will significantly take their emissions below business as usual… that for me will be a success.”