Until this summer, I thought of light pollution as mostly an issue that harms sea turtles. In my mind, it was also annoying for humans who can’t enjoy the night sky, including stars and the northern lights.
I started learning more about the harm light pollution can cause in the natural world last spring, when we’d first moved into our new townhome. It’s in a row of six townhouses, located just outside the city limits of Bemidji, Minn. At the peak of the roof, between each townhouse, is a light that turns on automatically at night and stays on all night, without any option for residents to turn them off.
The lights attract May beetles, sometimes called June bugs, mostly in the month of June. The beetles fly into the walls and many of them land in unsightly piles on our front sidewalk, around our front door and some on our back patio. Some die there right away. Others scramble around drunkenly, often flipping themselves over or wedging themselves into cracks of the foundation, where they die in the hot sun radiating from the sidewalk.
Mayflies are another insect that is attracted to the lights outside our home and died in large groups on the sidewalk. I don’t recall a large number of Mayflies at our home last spring, just in town near Lake Bemidji. This year, however, there was a mass of dead Mayflies crushed on our sidewalk in the arc of where the light hits the sidewalk at night.
Personally, pest or not, I don’t like to see living creatures killed or suffering because of human interference. In fact, my daughter and I have spent quite a bit of time rescuing what living bugs we can.
A lot of people may not see a good reason to care about insects dying because of outdoor lights. However, according to the International Dark-Sky Association, declining insect populations are a problem for all creatures that eat those insects or plants that rely on them for pollination. We humans may dislike insects but they do have an important role to play in our world, whether we understand or care about that role or not.
The glare from artificial lights can also interfere with the nighttime breeding rituals of frogs and toads, the International Dark-Sky Association says. In fact, research scientist Christopher Kyba says in the link above that artificial light is probably the biggest thing humans have done to impact nocturnal animals and scientists are only beginning to understand what a huge effect it is having.
An article in Massive Science helped educate me on the impact light pollution has had on the growth of plants, another aspect I hadn’t thought of before. It also introduced me to the acronym artificial light at night (ALAN). ALAN is a serious problem but it also made me giggle a little since the acronym is a name. It got me thinking of the Karens and Alans of the world who just can’t help but cause harm by complaining to the manager when it’s not warranted or by causing insomnia for the whole neighborhood with their extra-bright floodlights.
There are some things that individuals, groups and businesses can do to reduce light pollution. I found a really interesting research paper published in Entomological News in 2016, which looked at what lights attracted the most insects. The study concluded that incandescent light bulbs attracted and killed the most insects and spiders. LED lights, especially warm color temperature LED lights, caused the least amount of harm. Replacing outdoor lights with LED lights could have a significant impact on insect deaths.
I also found an article posted at The Earth Project, which outlined six ways light pollution (that nasty ALAN) impacts the environment and how to help. It includes a really good visual of the difference between an inner-city sky and a dark sky, plus the shades of sky in between. The best part was actionable suggestions to help reduce light pollution, such as installing motion detector lights, dimmers, bulbs that aren’t as bright, timers for outdoor lights and asking cities to dim street lights. The last tip, for shielded lighting, included another great comparison image that illustrates how shielded lighting can make a difference, if not for individual creatures, to reduce light pollution spilling out into the night sky.