How Shining a Light at Priorities Can Heal

Light Pollution

That’s me with “Turtle Watch” team transporting the precious cargo of endangered sea turtle eggs removed from a threatened nest.

There is growing awareness that the scale of humanity’s consumption of fossil fuels is a problem. Unprecedented heat waves, wildfires across the globe, deadly flooding, is finally getting mainstream attention, though ridiculously insufficient real action. Importantly, in addition, a slow, but growing trickle of systems-thinkers are also beginning to point out that simply converting the current scale of consumption to renewable energy sources is not viable. The massive expansion of mining and land conversion necessary to create the batteries, solar panels, energy farms, etc. would rapidly accelerate the already severe crisis of species extinction and ecosystem collapse.

Coupled with climate change and the habitat loss associated with our energy consumption, light pollution is a growing problem that gets little attention. In fact, I suspect many people don’t even realize it’s an actual thing, but, alas, it is. It is also something that many of us have power to do something about.

At this point, just over 90 percent of all humans on the planet have access to electricity and it is impossible to overstate how much this incredible tool has expanded human capacity and experience. However, the ease of flipping a switch and flooding the world with artificial light has some significant downsides – harming species from fireflies to fish, to humans.  

Coastal cities that run intense overnight lights in hotels, office buildings, airports, etc. can actually trick coral reefs into spawning at times that are not optimal for reproduction. The release of coral eggs is triggered by the lunar cycle on certain nights of the year. These are timed so that all the coral on a given area of reef spawn at simultaneously to maximize the chances of fertilization. In contrast, reefs that exist near brightly lit up cities, are now showing that the lit and unlit portions of the reef are spawning on different nights. The unlit portions are still responding to lunar phases; the others are being tricked by artificial light. Coral eggs are less likely to be fertilized and survive if the spawning events take place on different nights.

New studies suggest that artificial light also has harmful effects to species of fish that reproduce on coral reefs. A common trait of these species is that eggs hatch after dusk, probably as a means of avoiding predation. Studies show that in habitats experiencing chronic light pollution, hatch rates are greatly reduced. In addition, at the larval stage most fish species are attracted to light and so will remain concentrated on artificially lit reef areas instead of dispersing to other portions of the reef even though the artificially lit areas decrease the chances of survival and reproduction.

In 2010, I was part of a team documenting the effects of the BP Deepwater Horizon oil spill disaster. One of the activities I took part in was relocating nests of endangered sea turtle eggs that were in oil-fouled portions of the beach. The effort was led by groups of locals who years earlier had formed “Turtle Watch” brigades to protect turtles from various dangers, one of the greatest of which was light pollution. Like many other marine species, the turtles use moonlight to navigate. As soon as the baby turtles emerge from nests in the sand, they start moving toward the brightest light, which for millennia has been the ocean surface lighted by a moon and star-filled sky. Now however, hatchlings often get confused by brightly lit buildings and resorts and begin moving inland leaving them open to increased predation and getting crushed by cars. In addition, female sea turtles ready to lay eggs will often refuse to come ashore on brightly lit beaches even though they are genetically wired to return to the beaches on which they were born.

The sources of artificial light impacting marine species go beyond coastal cities and resorts to include structures like cruise ships, oil rigs and platforms, and hotels constructed directly over coral reefs and bays.

Birds are also affected by artificial light. Many species, from hummingbirds to songbirds, make incredible migration journeys covering huge distances, mostly at night, using moon and star light to navigate. Artificially bright human settings can draw them off-course. In certain conditions, such as fog or dense clouds, this leads to massive death events as birds slam into brightly lit windows.

Light pollution also has a tremendously damaging impact on insects. The fate of insects may not trouble many people but just consider, insects are an irreplaceable component of the food web and responsible for pollinating countless species. The food web would go on just fine without humans, but without insects it would absolutely collapse in a very short time. In addition, for those who notice, insects themselves are glorious, sacred creatures – think butterflies, dragonflies, the amazing communal society of ants, and on and on.

One of my favorite insects is the firefly. When I was about ten years old, my family made a big road trip from Washington state to Oklahoma, where all my parents’ relatives lived. It was the first time I had experienced fireflies and it was an instant love affair. The nights were literally aglow in a slow-moving, magical dance of soft luminous flashes. Fireflies were everywhere. I was enchanted.

About thirty years ago, my mom and dad moved back to Oklahoma. Shortly after they bought their new home they installed a tall, bright light between the house and shop and ran it all night long, believing it was “security lighting”. Many years ago, I tried explaining to my mom the light pollution issue to no avail. Earlier this summer, I was back in Oklahoma dealing with the sale of my mom’s property. One of the most depressing aspects of the whole experience is that there were no fireflies. I mentioned it to a couple of locals and they said, “Yeah, we really just don’t see them anymore.”

Fireflies communicate and attract mating partners through flashing their lighted abdomens. Artificial light diminishes their flash response and makes it harder for potential mates to see them. Pesticides and habitat conversion are certainly major disruptors for insects, but light pollution is an added layer of damage that many species cannot adapt to. A 2019 study showed that artificial light – from street lamps and cars to enormous gas flares from oil extraction – are a key driver of what is now being labelled the “insect apocalypse”, referring to the alarming decline of insect species around the globe.

To those who recognize that humans are a part of nature, rather than apart from it, it should come as no surprise that light pollution harms humans along with other species. Artificial light affects our melatonin levels, alters our sleep patterns and has been linked to diabetes, mood disorders and increased risk of various cancers. On top of that, as light pollution expands, we lose the gift of viewing the magnificence of star-filled skies and full moons – an incalculable loss really.

Night, and darkness, is literally habitat and when we light it up, we fragment habitat that myriad species require for sleep, mating, migration, flowering, hunting, hibernation and more. We also diminish our own experience of this amazing planet that is our only home.

Fireflies, hummingbirds and coral reefs may not be able to prevent light pollution, but humans can. The good news is that scientists and conservationists are now recognizing light pollution is indeed a real thing. In fact, it’s been given an acronym – Artificial Light at Night (ALAN) and it is getting a lot more attention and study. Also, “Dark Sky” Initiatives are on the rise with individuals and even cities taking part. Here’s a link to Dark Sky International with more info and actions we all can take to reduce light pollution. These include turning off outside lights when not being used, using warmer color and less intense bulbs, drawing curtains or blinds at night to reduce spill out of interior light into the outdoors. Here are a couple sites with info for individuals – Durango CO, Portland, OR Audubon.

Some cities are also taking action to curb light pollution. For example, Hollywood Florida has adopted an ordinance requiring oceanfront properties to dim their lights at night or be fined as a measure to protect sea turtles. In addition, seventeen US states and several European countries have begun taking steps to reduce the impacts of artificial light.

Modern humans reached a point where our technological ingenuity outstripped our wisdom. And we tricked ourselves into believing we are above and outside the laws and rhythms of nature. We’ve created systems and constructs we believe are more real than the natural world upon which we are 100 percent dependent. When the stock market falls 20 or 30 percent, “news” outlets blast it across the headlines. But the fact that the number of insects worldwide has fallen 75 percent over the last fifty years doesn’t even get a shout out.  

A world without fireflies is such a dimmer, diminished world. It would make so much more sense if we’d shine a light into our own misjudgment and mis-aligned priorities instead than shining artificial light into any more of the remaining natural world.

NOTE -- Here’s a really good piece from BBC about the problem of light pollution.