I think very few people actually worry about it. That's not representative of the people who post here, but just looking around at how people live and the cars they drive and the homes they build and businesses running 24x7 with all the lights on, parking lots lit up all night after stores are closed, towns wasting many kilowatt hours on Christmas lighting, etc. I see no real evidence that anyone but a small minority of people are even thinking about it, much less worrying.