A Lightbulb Goes on in My Head

Yes, of course:

A global switch to efficient lighting systems would trim the world's electricity bill by nearly one-tenth.

That is the conclusion of a study from the International Energy Agency (IEA), which it says is the first global survey of lighting uses and costs.

The carbon dioxide emissions saved by such a switch would, it concludes, dwarf cuts so far achieved by adopting wind and solar power.

Relatively easy and painless, too: what are we waiting for? Let there be light.