In Copenhagen on December 10, George Soros, Chairman of Soros Fund Management and the Open Society Institute, unveiled a plan to help address a core element of a global climate deal - financing climate mitigation and adaptation in the developing world.

The key word is "Special Drawing Rights," or SDRs - arcane financial instruments that when converted into any one of four particular currencies, can tap into idle reserve accounts at the International Monetary Fund. Those funds would be placed in a special "green fund," which would be used to help the world's poorest countries commit to a global climate deal.

The message is twofold.

First, SDRs can give the world's least developed countries a decent amount of what they need for climate mitigation and adaptation (roughly $7 billion per year for 30-40 years in loans, grants and equity financing, according to the European Climate Foundation). This would help address one of the key obstacles to a global deal in Copenhagen - the dearth of financial support for developing countries to change their infrastructures to reduce emissions, and to adapt to the current and future effects of climate change. Though SDRs would represent just one potential source of that financing (the developing world is asking for around $100-$150 billion a year by 2030), all new sources are welcome in a situation where wealthy countries are finding it difficult to marshall the necessary funds to assist the poorest countries.

Second, this money is already out there, and would not need to come from the taxpayer base of any country, including the United States. While revenues from the auctioning of carbon credits, airline bunker fuel levies, Congressional appropriations, and the redirection of fossil fuel subsidies are all credible, and in most cases, necessary sources of financing, SDRs represent a source that could be a winner, in both political and economic terms.

But what exactly is an SDR, and how might such a proposal work? George Soros, and the European Climate Foundation, articulate it far better than I can. See the full text of Mr. Soros' speech in Copenhagen, and a report from the European Climate Foundation.