A lawyer I know, who, I am convinced, likes to rattle my chain from time to time, recently sent me an essay entitled “The Green Thing.” (It’s all over the web, but it looks like it may have originated here.)

It’s about an older lady at a supermarket checkout who, after being scolded by a presumably young cashier that plastic bags aren’t good for the environment, apologizes for her unhipness, noting that “we didn’t have the green thing back in my day.”

And then the irony sets in. In her day:

A charming story, I replied to the lawyer in question, but overly simplistic.

Our Energy Efficiency of Today

The fact is that we’ve become a whole lot better at converting energy into