> There's only so many lights that you'd put in a given area to achieve the same result, even if you add more for aesthetic reasons: there's only so many lumens that are useful in an area.

You'd think that, but we now see people experimenting with light bulbs that are bright as the sun, purportedly to improve their mood: https://news.ycombinator.com/item?id=21660718 "I bought an extremely bright “corn cob” style bulb. It emits as much light as about 40 incandescents, and produces enough waste heat that it needs an internal cooling fan to dissipate it." It's not difficult to imagine a future where this is the norm, and people having anything dimmer than full sunlight indoors is considered medieval and backwards. We can always find new limits to what is "useful".

UPDATE: In that article, the author also says this of the lightbulb: "It draws about 2 kWh per day (assuming 8h of usage), which costs about $0.30 at typical rates. This is comparable to one day of a modern fridge or one load of laundry. Power is cheap, folks!" This is a perfect example of why we need to talk about climate justice, because the average American refrigerator consumes more energy than an average person in many countries: https://www.vox.com/future-perfect/23106061/energy-inequity-...

The rest of the world cannot live the way we currently do in the USA, if we are to avoid catastrophic global heating.