Well let's do as many as we can. No reason to handicap ourslelves for the future.Increasing national energy efficiency requires that application of single things.
It doesn't materialize from fiat.
There is a reason, cost! We waste more of the energy than any other country in the world, and that keeps getting more an more expensive, which has a severe negative effect on our economy. Its already hurting our economy. Its one of the reasons we are so slow in recovering from the recession.There has to be a reason for a nation to be more energy efficient though.
So probably better to just wait till we get to depression mode before we act?Sometimes cost isn't enough reason for most people, sometimes it is.
Depends on each situation and "single thing."