National Geographic has a great photo essay and article on the effects we humans have had through our insistence of lighting up the night sky.
For most of human history, the phrase “light pollution” would have made no sense. Imagine walking toward London on a moonlit night around 1800, when it was Earth’s most populous city. Nearly a million people lived there, making do, as they always had, with candles and rushlights and torches and lanterns. Only a few houses were lit by gas, and there would be no public gaslights in the streets or squares for another seven years. From a few miles away, you would have been as likely to smell London as to see its dim collective glow.
As with many human interventions, we are only beginning to realize the effects on species and normal patterns that this is having.
One of the quickest complaints I receive is when I light goes out, as though the safety of the whole community is at risk, or perhaps someone is going to take advantage of the new-found darkness to undertake some evil-doing or another. If I had myway, I would do an audit of the lights in a community and determine which lights should be on for certain periods of time, and typically, I would have to recommend against all night lighting in almost all residential areas.
[ad#125-right]One solution that has been available for a few years is the “Dark Sky” type of lighting that throws light downward only, wasting less light to the night skies. This is a solution that does little to combat the growing prevalence of lights everywhere, sure they might point down, but they still use a lot of energy. I worked out from a local example, that the average household is paying somewhere in the order of $70 to $100 a year for the street lighting in town, which is just part of their taxes. As the cost of energy increases, (as with gas), the demand for lighting will decrease, as people will not want to pay for something more expensive, and anyway, people will be driving less, so the average citizen would be subsidizing those who drive.