Why the Night Sky Matters: The Ramifications of Light Pollution

Carrie and I are lucky enough to have a hot tub in our back yard, overlooking a pretty spectacular ocean and mountain view. We often soak for a while and talk about the day’s activities just before retiring to bed (I sometimes alternate with a quick plunge or two into our unheated pool). Last night we were taking advantage of the break between winter storms to “jacuze” when I noticed that the cloud cover had so dispersed the city lights of L.A. and Santa Monica that it lit up the sky even 20 miles out into Malibu. On an otherwise moonless night, it had become light enough to simulate dusk all over L.A.. Can you imagine the amount of manmade light it takes to have that effect? Of course, that got me thinking about all the ways in which light permeates our lives in ways both good and bad.

These days, mentioning the words “pollution” or “environment” raises hackles in some, perhaps most people. Political blinders go up, knee-jerk responses engage. Support for classically green renewables like wind or solar power usually comes with unequivocal and emotional disdain for any and all variations of nuclear. On the same token, those who question the legitimacy of anthropogenic global warming often display a lack of concern for the effects of fracking, industrial pollution, or rampant use of agricultural pesticides. Now, I’m not wading into that morass, mind you. This isn’t the place for that. I am, however, calling to attention the fact that both (albeit amorphous, roughly defined) groups have a major blind spot: light pollution. And it’s not that they reject it as a problem. It’s that they are simply unaware it even exists (maybe it’s all the bright lights).

So what exactly is light pollution?

Well, it’s not light as in mild, harmless, or barely-there. It’s not gentle pollution, and it’s nothing like “light to moderate drinking.” Light pollution is characterized by excessive amounts of artificial light. Light that shouldn’t be there, light that you can’t escape from. It’s light that fills city streets at night – all night – and extends upward to obscure our view of the stars. It’s the blinding white and blue light streaming from big screen TVs, laptops, and lamps, and it’s the little niggling lights that pepper the interiors of our homes, winking at us from Blu-ray players and gaming consoles and clock radios even as we (try to) sleep.

In other words, light pollution exists inside and outside our homes. It affects both the environment at large and the individual inhabitants within. It is micro and macro. In the modern world it is, for the most part, inescapable.

I won’t delve too deeply into the negative effects of artificial light on human health as it relates to circadian rhythm, because I’ve already covered those. Quickly, though, some of the research:

Night time exposure to blue (artificial) light can suppress melatonin production, thereby disrupting sleep, reducing quality of sleep, throwing off circadian rhythm, and even promoting certain cancers.

Computer light exposure at night affects circadian rhythm and cognitive performance.

Continuous light exposure might hamper our ability to process carbohydrates, particularly in the liver.

According to a large review titled “The Dark Side of Light at Night,” (PDF) shift workers (a proxy for night time light exposure) get more cancer, heart disease, and are more likely to be obese. They also experience great oxidative stress loads and have compromised immune systems. Shift workers might represent the extreme end of nighttime light exposure, but they show the potential negative ramifications of even constant low-level exposure for everyone else.

But besides all the measurable, objective, physiologically-harmful effects of too much artificial light, there are the intangibles. That’s what this post is really about. Who else was lucky enough to spend their childhood summer nights on the roof or in the open field, gazing up at the millions of stars set against the backdrop of eternity? I was, and it’s what I still look forward to most of all about camping. When I sneak away from the fire and catch a break in the canopy, I stop and stare up above at the stars, those same heavenly mysteries that got our ancestors thinking, poking, prodding, and striving for more. Though today I know that they represent far flung galaxies of eons past and that that bluish “star” is actually Venus, a planet covered by volcanoes and rocky deserts – while thirty thousand years ago mankind looked up and concocted wondrous tales of gods and celestial beasts – that knowledge is suddenly meaningless once I begin to gaze. I’m caught up, emotional, dare-I-say “spiritual” – a lot like how our ancestors must have felt when they looked up at night. I’m lost in the limitlessness. I’m a kid again, suddenly struck with the realization of just how small I am and of the extrinsic meaninglessness of it all. Nature, remember, is neutral, and it becomes evident that we create our own meaning – it’s actually intrinsic, it comes from within – and set our own path. It’s all on us, and I’m reminded of this essential fact because of that brief brilliant moment with the stars.

If we allow light pollution to progress unabated, we lose that relationship. Many of us have, for all intents and purposes, already lost it – if we ever had it at all. But at least the opportunity remains. I mean, the stars are still there, if you get the heck out of Dodge. And if you can drag your kid outside city limits to shift his gaze from smart phone upward toward the relatively untouched sky, he might learn something about what it means to be human. Strip away all the luxuries and technology and just stick a modern city dweller in an open meadow in the middle of nowhere in the black of night and direct his or her attention skyward. If only for a moment, he’ll be like Luke Skywalker staring out at the night sky in “A New Hope” (with fewer suns) and thinking of rebel fleets and hyperspace travel.

That brings me to my final beef with light pollution: the extinguishing of a potent source of inspiration for greatness. From the ancients using astronomy to align their superstructures, to Newton drawing on the movement of celestial bodies to formulate basic theories of physics, to poets and authors and other artists (“Starry Night,” anyone?) creating work after a night spent stargazing, we do and have done great things with regular access to unfiltered night skies. I tend to think we have a lot ahead of us, too, if we’d give ourselves the chance. Misappropriation or lack of funding is the oft-cited cause of the US space program’s sorry state, but I feel like a lack of public fervor for all things stellar is at the root of it. People just don’t – or can’t – look up and marvel at the amazing ocular feast residing above anymore, and so they don’t dream of visiting it. Public officials don’t feel pressured to support it (besides, there are far more lucrative things to be doing with our tax money, like subsidizing their friends). Kids don’t seem to dream about becoming astronauts. I dunno about you, but that’s sad to me. The childhood version of Mark Sisson figured there’d be interstellar commercial travel and permanent bases on Mars by 2012. Adult version of Mark Sisson is highly disappointed that there is neither (but he hasn’t quite lost hope).

But we can’t go out and bust street lights with slingshots; we’re not extreme Luddite/Dennis the Menace hybrids. We can, however, make changes to the immediate environment. Our homes and our habits can change. So, if there’s an action item to be derived from this post, I guess it’s this: turn off the lights, go outside, preferably somewhere remote, look up, and take it all in. Take your kids with you. Foster the innate human obsession with the stars. Watch young eyes light up and mind-expanding thoughts of eternity and possibility germinate in growing brains. Then, set them loose and see where they go and what they do. I bet it’ll be pretty good.

Who else loves – nay, needs – the stars? Who else imagines how great things would be if we could actually step outside our living quarters, look up, and see the galaxies laid out before us in excruciating detail? Who else wishes that stargazing was no longer the strict province of campers and hunters and country-living? I realize that progress is inevitable and civilization butts heads with nature, but there’s got to be a better way.


Chime in the comment section. Let everyone hear about your love for the stars. And if your relationship with the cosmos has grown stale (or you’re a stargazing virgin), then get out and see them (so you know what we’re all blabbering about)!

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

If you'd like to add an avatar to all of your comments click here!