When we think of habitat destruction, the first things that come to mind are probably bulldozers in the rain forest and oil spills over tropical reefs. However, studies show light pollution may be destroying the habitats of animals in our own backyards.
Humans, animals, and plants all rely on the 24-hour cycle of light and dark, day and night, to regulate sleep, predation, migration, and mating behavior. When electric lights boggle those patterns, the whole ecosystem can get messed up.
Species Hurt By Unnatural Light Patterns
- Fireflies, which use distinctive flashing patterns to attract mates, have a more difficult time doing so around streetlights. Researchers have seen their populations decrease around areas with generous outdoor lighting.
- Mayflies, which only have hours (maybe days) to reproduce, get distracted by electric lights and die before mating. This has reduced their population, along with those of their predators dramatically.
- Migratory birds often fly at night to avoid predators and forage in the daylight. However, when they encounter a city’s skyglow, they can no longer use celestial cues to navigate, and may end up stuck and disoriented, circling the artificial light until they’re exhausted.
- Nocturnal predators like owls, bats, raccoons, and coyotes lose the ability to hunt in the cover of night, and their prey cannot hide as easily.
- Baby sea turtles, of course, are practically the spokesanimal for light pollution. Many of those little guys don’t make it into the ocean because they’re distracted by the lights on land.
Okay, so light pollution isn’t good. But perhaps you’re thinking, if we turn off the lights that illuminate our streets and sidewalks, homes and buildings, they’ll become dangerous. Car accidents are bound to increase on dark, busy streets, and walking on sidewalks out at night would be scary to say the least. Not to mention a poorly lit home is a target for sinister intruders.
So what do we do? Is there any sort of compromise?
New LED lighting offers some hope, but it’s certainly not all sunshine and rainbows.
How LED Light Can Help Decrease Light Pollution
- It’s quite easy to control LEDs remotely, or program them with computers. We can dim them or turn them off with little hassle, to only use light when we absolutely need it.
- Sometimes animals aren’t influenced as much by different kinds of light. LED lights come in a spectrum of different colors. Red and amber LEDs can safely illuminate beaches while not distracting those cute baby sea turtles.
- LEDs also don’t emit UV light, which is what attracts insects like mayflies to their untimely deaths.
How LEDs May Add To Light Pollution
- Standard cool white LED lights could cause a change in color of the urban skyglow. More blue light scatters farther in the atmosphere, increasing skyglow. Plus, this blue light can suppress melatonin levels in animals and humans, further disrupting circadian rhythms.
- LEDs use much less energy than standard filament lights, which saves cities and buildings tons of money. It can be incredibly tempting to use this money for more and more lights, increasing light levels.
Other Ways To Counteract Light Pollution
Obviously, this is an ongoing issue that requires much consideration and innovative thought. For now, green construction codes and conservation programs have stepped in to help curtail the problem. These have begun making reduction of light pollution mandatory for green buildings.
Voluntary programs like Lights Out, fostered by the National Audubon Society, have started enlisting building owners to turn off unnecessary lights during migration seasons. Experts estimate Lights Out has saved over 10,000 land birds each year in 21 North American cities. Check out these two photos of the Chicago skyline, one of the first cities to dim the lights of their tall buildings to help the birds:
To learn more, check out this recent article from Lighting.com.