posted 5 years ago
It's a pretty good proxy, but industrial activity not associated with dense urban areas throws it off. The best examples are the oil patches in western North Dakota. west Texas, northern Alberta and Prudhoe Bay showing the bright light from all the wellhead flaring. In terms of where you might want to locate a homestead, though, those places could have even more negatives than a big metroplex. So it's still a really useful map either way you skin it.
Another thing to be mindful of is how excess nighttime lighting throws off the natural patterns of movement and behaviour of animals that are nocturnal. Some of these critters are providing important services in our landscapes and this is one of the arguments behind campaigns for dark skies.