Meet ALAN, the Bad Guy You Didn’t Know You Knew
No, ALAN isn't a shadowy figure from a spy thriller or that guy from the internet memes. ALAN stands for Artificial Light at Night, and its quietly wreaking havoc on our world in ways we're only starting to understand. It might not have the flair of a blockbuster villain, but ALAN's impact is as real as it is far-reaching.
By 2050, an estimated 68% of humanity will be living in urban areas. That means more people, more buildings, and, inevitably, more lights switched on to keep cities humming after dark. Streetlights, glowing skyscrapers, billboards—it's a 24/7 show. But all that light comes at a cost.
For humans, ALAN (like bright overhead fluorescents and digital screens) is a disruptor. It messes with our sleep cycles, suppresses melatonin (the hormone that helps us sleep), and increases risks for obesity, depression, and even some cancers. It's as if our bodies are perpetually jet-lagged. But the story doesn't stop with humans. ALAN is an ecological disaster for wildlife and ecosystems, too.
A World That's Too Bright
Take insects, for example. Sure, they might seem like pests, but they're the foundation of countless ecosystems. ALAN draws them to their doom in a phenomenon called "fatal attraction." Moths endlessly orbit streetlights, exhausting themselves, while others fry on hot bulbs. As their numbers dwindle, it's not just bad news for them but for everything that relies on them—birds, bats, and even plants that depend on pollination.
Many animals display what researchers call "lunar phobia"—they scale back activity on moonlit nights to avoid predators. But thanks to ALAN, moonlight is literally being outshone. The night sky, once softly illuminated by stars and the moon, is now overwhelmed by city lights that remain bright regardless of lunar phases. For creatures that rely on the moon for navigation—like dung beetles, migratory birds, or sea turtles—this is like having their GPS replaced with static.
The cycles of light and dark created by lunar phases are vital cues in the natural world. Animals have evolved to synchronize their behaviors—like foraging, mating, and migration—around these predictable rhythms. For instance, sea turtles hatch during the darkest nights to avoid predators and use the moonlit horizon to orient themselves toward the ocean. Similarly, migratory birds rely on moonlight for navigation during long nocturnal journeys. Even dung beetles, remarkable navigators in their own right, use the moon and stars to roll their dung balls in a straight line toward safety.
When artificial lights cancel out the natural shifts of light and dark, these species are left disoriented. Sea turtle hatchlings might crawl toward hotel floodlights instead of the ocean. Birds can veer off course or collide with illuminated buildings, wasting energy or dying in the process. Dung beetles, confused by the artificial brightness, struggle to complete their essential cleanup duties, disrupting the ecosystem's nutrient cycles.
Moreover, the constant brightness caused by ALAN removes the environmental signals animals depend on to regulate their activity. Predator-prey dynamics, for instance, become skewed. Predators may exploit the extra light to hunt longer, while prey lose the protective cover of darkness. This imbalance disrupts not only individual species but also the delicate web of interactions that make up ecosystems.
Lunar cycles are a fundamental part of life on Earth. ALAN's intrusion into these natural rhythms is like an all-night party in a library: chaotic, disorienting, and impossible for anyone to thrive in.
What Can Be Done?
The good news? There's a lot we can do to stop ALAN:
Shielded Fixtures: Directing light downward reduces waste and minimizes glare that affects both people and wildlife. This is particularly useful for residential areas and game reserves.
Warm-Toned Bulbs: Cooler, blue-hued lights are especially disruptive to nocturnal wildlife like bats and insects. Using warm-coloured lights, such as amber or red LEDs, is a simple change with big benefits.
Timers and Motion Sensors: Ensuring that outdoor lights switch off when not in use can save energy and reduce light pollution—a double win for households mindful of both their electricity bills and Eskom's load-shedding schedules.
Homeowners and Businesses: Simple steps like using dimmer porch lights and switching off illuminated signs overnight can make a big difference.
Local Campaigns: Organizations focusing on conservation, such as BirdLife South Africa, can run campaigns highlighting how reducing light pollution benefits both wildlife and iconic species or nocturnal predators like owls.
Change starts with understanding. Encourage local businesses to rethink their night lighting, support local efforts to dim city lights, and consider your own habits. Do you really need that bright white porch light on all night? Thoughtful, small steps add up.