The City of Light dimmed? It’s true. Thanks to a new law, not only Paris but all of France will see its lighting level reduced, beginning this July. Window lighting in commercial buildings and the lights on building façades will be turned off after 1 a.m., and interior lighting in office buildings will be off an hour after the last employee departs.
The new law promises to reduce carbon emissions and save energy — the annual equivalent of 750,000 households’ worth. Most significant is its potential to turn the tide against light pollution by changing attitudes about our unnecessary overuse of light at night.
In almost every U.S. city, suburb and town, the streets, parking lots, gas stations, and commercial and public buildings are lit through the night. The growth of this pollution has been relentless, yet slow enough that most of us haven’t noticed. Parking lots and gas stations, for example, are now often 10 times brighter than they were just 20 years ago, and light pollution continues to grow at 6 percent every year.
The cost of all this light, monetary and otherwise, is high. The connections to sleep disorders, cancer, diabetes and other disease are serious enough that the American Medical Association has declared its support for light-pollution control efforts. Every ecosystem on Earth is both nocturnal as well as diurnal, and light destroys habitat just as easily as any bulldozer can. And when eight out of 10 children born in the United States today will never see the Milky Way, we have even lost the stars.
The usual justification for these costs is that we need all this light for safety and security. This simply isn’t true.
No one doubts that artificial light can reduce the risks of being out at night, and no one is saying that we ought to exist in the dark. But increasingly, police, doctors, astronomers, economists, business leaders, communities and now the French government agree that we should reduce the light we use, and that too much brightness at night actually reduces our safety and security. Bright lights may make us feel safer. Alone, however, they don’t actually make us safer.
The research bears this out. In 2008, PG&E Corp., the San Francisco-based energy company, reviewed the research and found “either that there is no link between lighting and crime, or that any link is too subtle or complex to have been evident in the data.”
Others are even more to the point. Australian astronomer Barry Clark went so far as to conclude that “advocating lighting for crime prevention is like advocating use of a flammable liquid to try to put out a fire.”
Our own eyes tell the same story. Too much light at night actually blinds us with “disability glare” - something middle-aged and elderly drivers know all too well — and bright, unshielded lights make it impossible to see past them to where criminals might hide. (The next time you face a bright streetlight, block it with your hand and notice how much better you can see the area beneath and beyond the light.)
Numerous villages, towns and cities in Europe and the United States have initiated programs to shut off streetlights for at least part of the night. European cities such as Berlin and Copenhagen already have much lower levels of light than their U.S. counterparts, and even some major American cities, such as Tucson, Ariz., have strict lighting ordinances that require a level of light that most Americans would consider dim. None of these towns and cities has reported related increases in crime.
The new French law is to be applauded, not only for what it may do to save energy and reduce carbon emissions, but also for what it may help us to understand: True safety and security at night comes from making smart decisions, being aware of our surroundings and using lighting wisely.
If the City of Light can do it, why shouldn’t we?
Paul Bogard, who teaches creative nonfiction at James Madison University in Virginia, is the author of “The End of Night: Searching for Natural Darkness in an Age of Artificial Light,” to be published this July. He is also the editor of “Let There Be Night: Testimony on Behalf of the Dark.” He wrote this article for Bloomberg News.