Consumers are becoming more and more environmentally conscious. Of course, many municipalities have made recycling available for decades. Responsible homeowners make sure to separate out their glass, plastic, paper, and metal to keep it out of landfills. New technologies have also made it easier to reduce our carbon footprint. Energy-efficient appliances and lighting options, like CFLs and LEDs, have become the norm. Better insulation, double-paned windows, and more efficient heating and cooling systems make keeping cozy more environmentally friendly. But one source of pollution has only recently begun to be acknowledged. Light pollution just doesn’t get the same press as other types of pollution, and in most places, it is still entirely unregulated. But that doesn’t mean that it should be ignored. At Night Vision Outdoor Lighting, we take light pollution seriously and always design to reduce light pollution from outdoor lighting.
What is Light Pollution?
If you’ve ever noticed the difference between looking at the night sky in a city and deep in the country, you’ve seen the effects of light pollution. Light pollution is the excessive, invasive, or misdirected use our artificial lighting. It is the result of interior and exterior lighting in populated areas. When light pollution is bad enough, it can change the color contrast of the night sky, eclipse natural starlight, and disrupt the circadian rhythm (natural 24-hour cycle) of humans and wildlife. Unfortunately, as human populations spread and industrialize, light pollution has grown. If you look up at night and don’t see a sky full of brightly shining stars, you live in a bubble of light pollution.
In addition to the aesthetic effect of losing the night sky, light pollution has a serious impact on the environment. First of all, light pollution is defined as light that is excessive or escapes its area of intended use. All that extra light translates into billions of watts of wasted electricity and tons of carbon emissions.
Light pollution also creates giant islands of light that disrupt wildlife and entire ecosystems. Nocturnal animals are the most drastically affected. Both predators and prey use darkness to their advantage, avoiding detection as they hunt or hide. By turning night into day, the food chain is drastically altered. Many animals also use the nighttime for breeding rituals. Depriving these species of darkness can alter their life cycles and reproduction.
Humans also suffer from light pollution. Like most other living things, humans function on a 24-hour natural cycle that is closely tied to the changing light of dawn, midday, dusk, and night. By altering the appearance of light, human physiology is altered, resulting in sleep disruptions, increased stress, and other physical and psychological maladies.
Light Fixtures That Decrease Light Pollution
Light pollution can be greatly curtailed by using the right kind of light fixtures. The International Dark-Sky Association is the global leader in light pollution awareness. They have a great infographic that demonstrates “acceptable” versus “acceptable” light fixtures. You can find it here. The most important feature of any approved light fixture is its ability to shield light from escaping upward and outward beyond its intended target.
There are two main ways to shield light. The first is to use light fixtures that are capped. These light fixtures have a solid top over the bulb that prevents light from escaping upward toward the sky. This is the most basic form of shielding and should be a baseline for all lighting decisions. Unshielded lights, for example, globe lights on old-fashioned lamp fixtures, should be avoided. But the next step in preventing light pollution is to consider the cutoff of each light fixture.
The cutoff of a light fixture is the angle beyond which no light can escape. A full cutoff would be a light that shines absolutely no light above a 90º angle from the light source. In other words, all light is directed downward and outward, with none escaping toward the sky. Full cutoff, with no glare above 90º, requires the effective area of lighting to be reduced to no more than an 80º angle from the source. Standard cutoff reduces the effective lighting area to within 90º of the light source but allows some light to escape upward. Semi-cutoff light fixtures allow a larger amount of light to escape upward but may have at least a small cap to keep some light pollution under control. Zero cutoff lights allow light to shine equally in all directions, including upward toward the sky.
Reduce Light Pollution With the Right Bulbs
The type of bulb you use also makes a big difference in light pollution. The most harmful light pollution is short wavelength blue light. Light doesn’t have to appear blue to have short wavelength light. Any light that appears “cool” (has a lighting temperature of 4000K or more) is giving off a lot of short wavelength light. Short wavelength light scatters most easily into the atmosphere, causing the worst light pollution. Daylight also tends to be “cooler”, so the greatest disruption to wildlife comes from light at 4000K or more. The ideal light to use outdoors is “warm” light (around 3000K). This light is less harsh on the eyes and less disruptive to wildlife.
Lighting Practices That Reduce Light Pollution
Typically, outdoor lighting serves three primary functions: utility, security, and beauty. By examining each of these three functions, we can determine the best way to adjust our use of light to reduce pollution.
Utility is the function of outdoor lighting to make spaces useful at night. For instance, lighting a deck, garden, pool area or another area of your property at night increases usable living space. But just like you would turn the lights out in a room that you’re not using, there’s no need to light an area that you’re not using. Creating outdoor lighting that can be controlled in zones makes it possible to turn off lights that aren’t in use without turning off the whole system. One way to make sure you only have the lights on when you need them is to install motion sensors. The motion sensors make sure the lights go on when you’re present, but turn them off when automatically when you leave.
Security is another significant benefit of outdoor lighting. Some lights should stay on all night to discourage unwanted visitors. But other lights, especially really bright lights, can be put on sensors. Anyone approaching your property will be welcomed by a flood of light. But the lights can stay off when you don’t need them.
The third function of outdoor lighting, beauty, is the hardest to quantify. Of course, you want some lights to stay on all night to beautify your home and property. But do you really need them all night? Using a timer to shut the lights off once everyone is in bed can save electricity and reduce pollution. If you’re not sure how to set the times, 11 p.m. is a good cutoff time. After that, traffic is drastically reduced and very few people are outdoors.
The Importance of Lighting Design
One of the most significant ways we can reduce light pollution is with environmentally conscious design. When you work with Night Vision Outdoor Lighting, we’ll help you design a system that puts light everywhere you want it and nowhere you don’t. To schedule your free, no-obligation outdoor lighting consultation, contact us today.