Light pollution is insidiously creeping into our lives and like other forms of pollution, it impacts the way we live. It’s slowly and subtly changing our natural environment by altering patterns of nocturnal wildlife, increasing greenhouse gas emissions and affecting human health. To add insult to injury, it’s also costing us a great deal of money.
According to Dark Sky International, a non-profit recognized as the leading organization dedicated to preserving night skies, here in the United States, we spend over 3 BILLION DOLLARS every year on energy that is lost to skyglow, or the brightening of the night sky over inhabited areas. (insert photo)(See August 27th blog, Designing Landscape Lighting for a Healthy Environment - Meeting the Challenge of Light Pollution for a detailed explanation of light pollution and its harmful effects.) On average, most residential outdoor lighting layouts/displays/systems waste the equivalent of half a kilowatt-hour every night. It doesn’t sound like much, but over the course of a week, the squandered energy dollars could have run your dishwasher three times, or you could have watched a 50-inch tv for 3 ½ hours. As energy costs across the country rise, the potential savings improved outdoor lighting offers both individuals and our society in general becomes even more valuable.
If you’re considering installing outdoor lighting, or thinking about ways to improve your existing system, a report from The World Economic Forum’s “Nature Positive” paper highlighted 7 pollution halting suggestions from Dark Sky International.
Use Nighttime Lighting Sparingly.
Dark sky advocates are not pushing to eliminate all outdoor night lighting. Instead, they are urging people to use lighting responsibly. They suggest spending time analyzing where and when light is needed for safety and for enjoyment. Driveways, walkways, doorways should all have adequate lighting to minimize tripping and falls. Patios, decks and other outdoor gathering areas can be comfortably lit when in use and turned off when not.
Use the Lowest Brightness Level Possible.
Harsh, glaring light actually reduces visibility, making accidents more likely. In addition to safety hazards, repeated exposure to overly bright light is also known to cause eye problems ranging from dry eyes to cataracts. When selecting lighting, it is critical to check the Lumens as well as the wattage. Watts are a measure of energy use, but do not technically communicate anything about how much light is given off. Lumens, on the other hand, measure the visible light emitted by a bulb, or to put it succinctly, the brightness of a bulb. The higher the Lumens, the brighter the bulb. To protect dark skies, choose lighting that accomplishes your goal with the lowest lumens
Use Controls that Make Lighting More Efficient.
Certain devices can add to your lighting’s efficiency. Timers and motion sensors allow lighting to automatically shut off when no-longer needed. Dimmers can allow you to adjust the light level according to the task.
Use Shielded Fixtures.
Fixtures that are designed to direct light downward to a specific area and purpose are much more efficient. Exposed light surfaces throw light beams upward, where it adds to light pollution, and outward where it adds to unnecessary glare. Many retailers now carry night sky approved fixtures that are designed to help reduce sky glow and glare.
Keep Lighting Contained to Your Property.
Light trespass can unintentionally invade your neighbor’s privacy. Glare from unshielded or poorly placed lights can cast glare into nearby yards and windows, disturbing both people and wildlife. Experts recommend mounting outdoor light fixtures well away from the property line, usually a distance of at least 4 times the mounting height of the fixture.
Use Warm Colored Lights.
Amber colored bulbs, or bulbs with a Kelvin number in the range of 2200 - 2700 give off a softer light that is much healthier for wildlife, but still usable for humans. (The Kelvin scale measures the color temperature of a lightbulb. A high number, 3000 and above, gives off bright, white light with blue undertones. Lower numbers emit softer light.) Warmer colored lights reduce glare and can enhance both indoor and outdoor experiences because of the soothing atmosphere they create.
Limit Blue Wavelengths.
We typically associate blue light with screen usage, but it has become much more prevalent in our daily lives since the advent of LED lighting. Many LED lights, especially those that are older, emit a great deal of blue light, which is known to be tied to an increased risk of eye disease. Mild symptoms include dry, irritated eyes and blurry vision. More serious issues such as damaged retinas and macular generation can also occur. LED lights with a Kelvin number of 2300 or less are safer for the eyes.
I have to admit that when thinking about air pollution or water pollution, I sometimes find myself questioning whether society can ever completely reverse the damage we have caused. The problems, their causes and their solutions are both complex and costly, requiring huge shifts in public policy as well as individual action. Eliminating light pollution, on the other hand, is well within the realm of possibility, especially if we all begin making small, but important changes now.
