The William J. Clinton foundation has arranged billions in financing to help a coalition of sixteen cities cut urban emissions by applying a range of energy efficiency measures to aging buildings.

Efficiency measures tends to get lumped in under the heading of conservation, but they really deserve to be their own full-fledged category of solutions to global warming. If conservation is simply doing less of a polluting activity, efficiency is doing the same activity with less energy. Turning off the lights is conservation. Screwing in a compact fluorescent light bulb is efficiency.

Efficiency measures deserve their own category because they are among the most important strategies for reducing emissions. Emissions reductions from efficiency projects are immediate (which is good), they are often cheap or even free (which is great), and they don't require individuals to make significant changes to behavior (which is important to quick adoption, no matter how much we might wish otherwise).

Details of the Clinton plan are unclear, but it appears the financing will take the form of a series of interest-bearing loans to be paid back through savings from energy reductions:

The financial instruments for paying for the upgrades are being designed by the Clinton Climate Initiative, set up by the foundation ...

The upgrades would be done by four international energy-services companies that are already seeing a booming business in such conversions. They would guarantee a particular level of energy and monetary savings for particular projects under the plan.

The financial instruments are still being designed, but they already have a name: carbon offsets. An exotic flavor of offset, to be sure, but offsets still the same.

To succeed, the plan will need to put in place all the normal machinery for offsets: a means for establishing emissions baselines, a set of approved protocols for reducing emissions, a measurement and verification procedure for tracking reductions, and a central registry to ensure emissions aren't double-counted.

These are problems that have been solved in other contexts, and it is exciting to see new flavors of offsets being developed. The Kyoto Clean Development Mechanism has identified over 200 categories of emissions reductions. Of these, 65 relate to energy efficiency.

This sounds like a lot, until you realize how narrowly defined most of these measures are. For example, Method 31 pertains to the capture of waste heat from iron kilns.

Improving the efficiency of city buildings is obviously much more important than improving the efficiency of the world's iron kilns. The immediate benefit of the Clinton program is the billions of dollars steered toward energy efficiency. But the long-term importance will more likely be the development of new techniques for plugging efficiency projects into global carbon markets.