It’s a truism that energy efficiency is a wonderful thing. Efficient devices — cars that travel more miles per gallon, refrigerators that use fewer watts per minute — don’t just save you money, they also tax our ailing planet less. It’s a win-win.
But what if, when refrigeration gets cheaper, you just buy a bigger refrigerator? Or if, when home air conditioners get more efficient, you spend your electricity-bill savings on carbon-spewing airplane flights? Zooming out: What if fuel efficiency makes driving so much cheaper that millions more people around the world buy cars and start driving?
The 19th-century British economist Stanley Jevons predicted — correctly — that the invention of more-efficient steam engines would lead to more coal getting burned. Today, the “Jevons paradox,” in which increased efficiency leads to increased energy usage, is referred to by economists as “rebound” (or, in extreme cases, “backfire”).
The wild complexity of today’s global economy — where new efficiencies at Point A in the manufacturing process can spur rebound at Point B, thousands of miles away — makes identifying and quantifying specific instances of the Jevons paradox fiendishly hard. But the most comprehensive review of the subject, published by Energy Policy in 2009, concluded persuasively that rebound rates are “larger than conventionally assumed” — and too frequently ignored.
More recently, the environmental economist Jeroen van den Bergh pointed out that, by underemphasizing the scale of worldwide rebound, the much-heralded 2015 Paris Climate Conference missed a chance to reckon honestly with just how hard it will be to cut emissions. To leave the Jevons paradox out of our calculations is more than just cooking the books: It’s cooking the planet too.
