Rebound effect

An interesting article in The New York Times about the rebound effect, that is, improved efficiency may lead to higher production and consumption.

While there’s no doubt that fuel-efficient cars burn less gasoline per mile, the lower cost at the pump tends to encourage extra driving. There’s also an indirect rebound effect as drivers use the money they save on gasoline to buy other things that produce greenhouse emissions, like new electronic gadgets or vacation trips on fuel-burning planes.
Some of the biggest rebound effects occur when new economic activity results from energy-efficient technologies that reduce the cost of making products like steel or generating electricity. In some cases, the overall result can be what’s called “backfire”: more energy use than would have occurred without the improved efficiency.

I think energy efficiency is not in itself a solution to all energy problems, but a piece of a puzzle that includes renewables, conventional fuels, awareness and changing consumption patterns (perhaps the most difficult).

Another article about this in The Huffington Post