I’ve been using the word “decoupling” to describe what is happening in the relationship between water use and population/economic growth. The phenomenon is common, and I blog about it a lot – water use going down even as population and agricultural productivity go up.
Now comes Robert Stavins, a prominent environmental economist, to argue that the word is not quite right. He’s talking about carbon emissions, but his argument generalizes to the way I’ve been using the word:
Decoupling is the wrong word to describe what has been happening. It is simply the wrong metaphor. When a caboose is decoupled from a train, it stops moving altogether. A better metaphor, although less linguistically appealing, would be a “slipping clutch.” The engine continues to transmit power, and as a result the driveshaft continues to rotate, but less than when the clutch was new.