THE ROAD FOREMAN OF ENGINES SAYS EARTH DAY IS EVERY DAY.
Pigouvian taxes or not, smoke inspectors on the Prison Point bridge or not, a clean-burning locomotive is a boon to the bottom line.
Some time ago, I came across some snarking at a General Motors executive who was touting a hybrid car and trashing global warming. There is no reason to snark. The Road Foreman of Engines gets it.
The sign is in the Cold Spring Shops collection. It is a replica of (variously) a Pennsylvania or Chicago and Western Indiana or Terre Haute Line roundhouse sign, depending on the observer.