I was at a talk on dematerialization a few weeks ago, and one of the speakers told "the parable of the Prius" to illustrate Jevon's paradox that efficiency gains do not necessarily reduce energy consumption (and from a climate perspective, greenhouse gas emissions). In the case of buying a fuel-efficient Prius, one saves a lot on gas bills but may be inclined to drive more since the cost per mile has dropped. Even if mileage is constant, the proceeds could be spent on a vacation to Mexico, offsetting and perhaps then some in GHG terms, the savings out of the tailpipe. It's also possible that savings could be poured into energy efficiency improvements, and seems to me that a rising energy/carbon price can conquer the paradox.

During the State of the Union address earlier this week, President Barack Obama spoke at length about clean energy, with nary a mention of climate change. This is the new environment in which America's energy policy is being made.

Just two years ago, Democrats were rallying to combat climate change, one of the most worrying challenges the country faces. But now, Obama has apparently given up his plan to openly fight climate change during his presidency. It's hard to imagine how, even in a second term, he would choose to re-fight the lost battle to create a cap-and-trade system.