Weekly newspaper of Three Rivers, California, and Sequoia-Kings Canyon National Parks

The right and wrong of outdoor lighting

Sarah Elliott


A dark night sky unobstructed by artificial light is as important as a river with crystal-clear water. Light pollution, although painless, has adverse effects on human health and the environment as much as a smokestack spewing filthy, black particulates.
Preserving the night sky in Three Rivers is not something that anyone else is going to do for us. It’s like bear-proofing your own trash can. We need a shared community consensus to do what’s right for the natural world of which we are such an intricate part here. 
Outdoor lights need to be voluntarily retrofitted by property owners so that light points to the ground where it is needed instead of the rays escaping outward and upward into the sky.
Take a look some night at the single outdoor lights at Kaweah General Store or Three Rivers Library. They are high-strength, on from dusk till dawn, intended solely to light up their respective parking lots and buildings, but transmit light into the atmosphere. The Kaweah General
Store’s light is so bright that it  could be a lighthouse guiding ocean vessels away from a rocky coast; instead, it is a hindrance to drivers as they approach on the highway as much as an oncoming vehicle that doesn’t have its headlights dimmed. A simple shield added to either of
these lights would direct the escaping light pollution and focus the rays downward while keeping the respective properties lit for safety and customer convenience.
When shopping for outdoor lights, look for the Dark Sky Compliant seal. This is a designation given to outdoor lighting fixtures that meets the International Dark Sky Association’s requirements for reducing waste of ambient light. 
Lights that fall into this category have features like being fully shielded and are within maximum wattage limits. The regulation was established in the interest of saving energy and maximizing safety while maintaining the natural ambiance of the night sky. Some communities only
allow Dark Sky-compliant fixtures to be installed outdoors; unfortunately, Three Rivers, with its beautiful, starlit, natural night sky, is not a community with these requirements.
Although the County of Tulare minimally touched on this important matter in the recently updated Three Rivers Community Plan, the recommendations have no teeth, so once again, one property owner may work to preserve night-sky features while a neighbor might not. This type of
governance creates more conflict than a uniform policy and ordinance that residents would eventually learn to live with.
Wildlife and ecosystems
For billions of years, all life has relied on Earth’s predictable rhythm of day and night. It’s encoded in the DNA of all plants and animals. Humans have radically disrupted this cycle by lighting up the night.
Plants and animals depend on the daily cycle of light and dark rhythm to govern life-sustaining behaviors such as reproduction, nourishment, sleep, and protection from predators. Scientific evidence suggests that artificial light at night has negative and deadly effects on many
creatures, including amphibians, birds, mammals, insects, and plants.
And if you don’t think an insect’s life cycle or an amphibian’s love life concerns you, it is best to remember the writings of John Muir: “When we try to pick out anything by itself, we find it hitched to everything else in the Universe.”
Human Health
By now, we’ve all heard about the importance of sleep on whole-body health. Humans also evolved to the rhythms of the natural light-dark cycle of day and night. 
But the spread of artificial lighting means most of us no longer experience truly dark nights. Research suggests that artificial light at night can negatively affect human health by increasing the risks for obesity, depression, sleep disorders, diabetes, breast cancer and more.
Like most life on Earth, we humans adhere to a circadian rhythm — our biological clock — a sleep-wake pattern governed by the day-night cycle. Artificial light at night disrupts that cycle and creates negative effects.
Our bodies produce the hormone melatonin in response to a healthy circadian rhythm. Melatonin production is necessary to  keep us healthy; it has antioxidant properties, induces sleep, boosts the immune system, lowers cholesterol, and helps the functioning of the thyroid, pancreas, ovaries, testes, and adrenal glands. Exposure to artificial light at night suppresses melatonin production. 
Discover the dark
If you would like to experience darkness, real darkness that your eyes won’t ever adjust to, take a tour of Crystal Cave in Sequoia National Park. When the guide turns off the lights, darkness will be experienced like rarely can occur in the outside world anymore, which could be why the cave is home to several unique species of invertebrates that don’t reside anywhere else.
Spending a night in the backcountry of Sequoia or Kings Canyon national parks is one of the best ways to experience all that the night sky has to offer. The constellations, the planets, and the meteor showers are incredible on their own, for sure, but to experience the Milky Way — the entire galaxy — is truly something worth crawling out of the tent to experience. 
Witnessing the Milky Way on a clear, dark night will forever alter anyone’s perspective on the importance and value of a night sky that is unobstructed by artificial light.