The Hidden Costs of Light Pollution: Protecting the Night for People and Planet

The night sky, once full of stars, is disappearing in many places because of light pollution—the brightening of the night caused by streetlights, billboards, and buildings. This artificial light affects not only what we see in the sky but also the health of humans, animals, and ecosystems. Birds that navigate by moonlight can collide with buildings, sea turtle hatchlings may head inland instead of the ocean, and insects lose the dark conditions they need to feed, mate, and pollinate plants. Over time, these disruptions ripple through food webs, affecting mammals, reptiles, birds, and plants alike.

Humans are affected as well. Artificial light at night can disrupt sleep, hormone cycles, and circadian rhythms, increasing risks of insomnia, anxiety, obesity, diabetes, and certain cancers. Blue-rich LEDs, screens, and nighttime signage make these problems worse, especially for children. Health experts, including the American Medical Association, warn that exposure to too much light at night contributes to these risks.

Communities, however, can design night lighting that meets human needs while reducing harm. Using shielded, downward-facing lights, warm-colored bulbs, motion sensors, and dimmers can protect both people and wildlife. Cities like Groveland, Florida, and Flagstaff, Arizona, have implemented lighting policies that preserve dark skies while maintaining safety and visibility. The U.S. National Park Service also provides guidance for outdoor lighting that minimizes skyglow.

Dark-sky preserves around the world—such as Big Bend National Park in Texas, Aoraki Mackenzie in New Zealand, and NamibRand Nature Reserve in Namibia—offer examples of what natural darkness can look like when light is carefully managed. Protecting darkness is more than aesthetic: it supports biodiversity, human health, and cultural practices. By reducing light pollution and supporting dark-sky initiatives, communities can reclaim the night for future generations, allowing them to experience a sky full of stars—a shared inheritance worth protecting.

Read the full article “The Hidden Costs of Light Pollution: Protecting the Night for People and Planet” by Reynard Loki

🔭   This summary was human-edited with AI-assist.