Dan Swetman
Sewn into darkness, innumerable and infinite, the stars have a history of inspiring us. They nudge us to unravel ourselves, to seek something deeper within and outside of ourselves. Under them, and in sight of our own Milky Way—a rare occasion for most of us, these days—we feel small and big at the same time, and we take with us perhaps a more graceful understanding of the space we take up.
On the less poetic end of the scale, a much-recounted story from 1994 details the early morning hours of Los Angeles after an earthquake left the city mostly without power. When the shaking stopped, many locals stepped outside to check on the damage done. Some noticed a strange silvery cloud in the sky and found it so eerie that Griffith Observatory received a “good number” of calls about it in the days after the earthquake. It was the Milky Way—a sight unseen by many Angelenos, thanks to light pollution.
Generally understood as excessive artificial light shining into the night sky, light pollution primarily comes in several forms: light trespass, or light going outside of where it’s needed; glare, or light that causes visual discomfort or temporary blindness; and skyglow, which is that familiar orangey haze usually visible over a large city. The latter is what eighty percent of the world’s population, and a whopping ninety-nine percent of Europe and the United States, sees when they walk outside at night. Using data from U.S. Department of Energy, darksky.org estimates that skyglow wastes $3 billion annually, and that’s just in the United States.
Outside of our own existential sense of wonder and wasting a good bit of money, does light pollution really have any bearing on what happens down here, even outside of major metro areas like Los Angeles? Is excessive artificial light at night bad enough to be a problem in Louisiana, and are the effects substantial enough that Louisianans should be worried?
The short answer is yes.
Environmental effects
Considering that much of our natural world has hinged its evolution on light and darkness, light pollution is, in fact, pollution. Let us count the ways: Many trees exposed to excessive artificial light cannot adapt to seasonal variations. Some tree frogs, such as Louisiana’s Hyla squirella, stop their mate-attracting night choruses, and some toads suffer developmental stunting under the stress of artificial light.
When baby sea turtles emerge from their shells on a beach, they’re attracted to the brightest light source—which would otherwise be the light of the moon reflecting off the ocean’s surface—but in modern times, they wander inland toward artificial lights, where there is far less chance of survival.
[You might like: Sea Change: In New Orleans, more chefs are opting for sustainable seafood on their menus.]
Louisiana lies at the end of the Mississippi migratory bird flyway—a migration route used by nearly half of all bird species and up to forty percent of waterfowl species. Birds that migrate at night are especially vulnerable to light pollution because they use light cues, such as the moon, stars, and setting sun to navigate. In an artificially-lit urban area, birds are drawn toward brightly-lit buildings. Researchers using radar to study the birds have determined that “once they fly through a lit environment, they’ll return to that lit source and then hesitate to leave it,” sometimes flying within the light until they drop from exhaustion. Birds get fatally disoriented by industrial burnoffs too: More than one thousand migrating birds of seventeen species were killed by a two-hundred and fifty-foot flame at a Baton Rouge oil refinery back in 1960.
Insects—who pollinate seventy-five percent of the planet’s crops and are currently experiencing an unprecedented worldwide population decline—have a particular relationship with artificial lights. A German study found a credible link between light pollution and the insect population decline, which isn’t surprising: half of all insect species are nocturnal and use light cues for navigation. On a similar note, Louisiana residents may have noticed their beloved fireflies disappearing from their backyards. Considering fireflies don’t even like full moons, and they communicate and attract mates by their own flashing lights, light pollution is a culprit. Parts of the animal kingdom use light cycles in ways we might not yet understand, so it’s difficult to calculate the full extent of the damage.
Humans appear to be affected by artificial light at night, with some alarming results. Artificial light exposure at night decreases melatonin in our bodies. Scientists are in the process of understanding the role of melatonin in humans, and lower levels of the “sleep hormone” might be the link between working night shifts and a documented uptick in breast cancer risk, obesity, and diabetes. In an Israeli study, women living in areas with brighter outdoor lights at night had a seventy-three percent higher chance of getting breast cancer. It may not be a coincidence then that Louisiana currently ranks second highest nationwide in breast cancer mortality.
Dan Swetman
Look to the stargazers
On a chilly Monday night in March, eight people met at Highland Road Park Observatory for the monthly Baton Rouge Astronomical Society’s Light Pollution Committee meeting. (The Observatory is a combined effort between BREC, LSU, and BRAS—as a partner, BRAS holds its meetings there.) Several years ago, the committee was formed by BRAS to begin a concentrated effort to darken the skies for stargazers in Baton Rouge. “Light pollution is peculiar among all forms of pollution, in that we could solve the entire problem in an instant,” said Scott Cadwallader, member of the BRAS LPC.
On a Unihedron Sky Quality Meter (SQM), light pollution is measured on a scale of 16 to 22—16 being the worst for stargazing. Christopher Kersey, facility manager at HRPO, said the Observatory’s location on Highland Road has been stuck at 18.7 for four years.
“The main problem with light pollution, both for unaided eyes and cameras, is that it lowers the contrast,” said Kersey. “Instead of looking at a star cluster or a nebula against a velvety black, you’re looking at it against dark gray, or light gray if the pollution is very bad.”
“Instead of looking at a star cluster or a nebula against a velvety black, you’re looking at it against dark gray, or light gray if the pollution is very bad.”
The solution to Baton Rouge’s light problem is more complicated than simply turning off the lights at night. John Nagle, chair of the Light Pollution Committee, explained that light sources like street lamps are installed and maintained by different groups within the parish, depending on where they are located; while other light sources such as parking lot lamps and residential street lamps may be privately maintained. This creates a situation wherein someone trying to change the lighting situation in Baton Rouge will have to track down and speak to many different people, which the LPC is currently doing.
And it’s further complicated, Nagle explained, because many of the lights they would seek to change are technically legal within Baton Rouge’s light regulations. That’s why the LPC’s present aim is to change the light levels outlined as violations in Chapter 14 of the city’s Unified Development Code (UDC), which outlines the regulations for lighting and light fixtures, among other things. Currently, the level of brightness that constitutes a violation against the lighting ordinance is still too bright for a hobbyist stargazer, according to the LPC.
[Read this: Star Trails: Natchez photographer Keith Benoist spends hours of time gazing up at the night sky.]
Nagle told a story about a man who lives behind a car dealership and called the LPC out to measure the light levels in his yard, which is surrounded by a six-foot fence. The measurement wasn’t bright enough to be considered a violation of the ordinance.
“The closest light pole to him was a hundred feet away, but even still, we could read a newspaper near his bedroom window,” said Nagle.
“The closest light pole to him was a hundred feet away, but even still, we could read a newspaper near his bedroom window,” said Nagle.
Lighting that contributes to skyglow comes not just from street lamps and private residences, but from private facilities such as sports arenas, car dealerships, and skyscrapers, to name a few. Lots of businesses illuminate their parking lots at night in an effort to improve public safety, and in some cities, parking lots in certain areas, such as New Orleans’ Central Business District, must be illuminated by law after a certain hour. While public safety is an important issue to address, a business can do so with the right light fixtures, referred to as a “full cut-off type fixture” or a “fully-shielded fixture,” both of which essentially prevent light from leaking out of the sides or the top. Baton Rouge’s UDC defines and mandates these fixtures, but older street lamps that were in operation and permitted at the time the UDC took effect are exempt from certain fixture regulations. Some of the older fixtures are clear all around, shining light directly into the night sky.
Dan Swetman
“There is absolutely no reason to shine light straight into the sky,” reminded Kersey.
The LPC members sat around a table while Nagle explained the progress he’d made over the past month. Part of his aim was finding out who has the power to change which lights. He has spoken to Councilwoman Denise Amoroso; the director of the East Baton Rouge Department of Transportation and Drainage, Fred Raiford; and several others who might be in a position to change the UDC and specific light fixtures to improve the problem. Though none of them had the authority to make the changes needed themselves, many assured their support in helping the cause.
Part of the Committee’s work is public outreach. They have presented these facts to government organizations, civic groups, libraries, and HRPO events. They also want to teach children about light pollution, because it will only get worse and will eventually be the next generation’s problem. “By 2040, they’re saying the brightest four to seven stars in the sky are all you’re going to see, in any metropolitan area, anywhere on the planet,” said Nagle.
Dan Swetman
While they ultimately decided not to pursue it at this time, the group discussed a new curriculum package available for high school science classrooms called Turn On the Night, wherein students learn how to create environmentally-conscious lighting strategies for urban environments.
As for the average citizen, Nagle’s rules of thumb include only using the amount of light you need, only where you need it—making use of light shields to prevent light trespass—and lastly, only when you need it. “If we could follow that, we would not have light pollution anywhere,” said Nagle.
According to Kersey, the best thing a citizen can do to help the bigger problem is to look around their own backyard, and determine if any lights around their property are shining into their bedrooms or, perhaps, hindering their stargazing hobby. “Contact the owners of those lights, whether it’s a neighbor, advertising firm, gas station manager, local public works, or other municipal office, strip mall owner, et cetera; and explain the problem,” said Kersey. “The explanation should include the fact that, in the case of [a person’s] yard, the lights may also be shining into a bedroom window, and switching to a more efficient light would save the light owner money.”
The LPC also actively encourages participation in the Globe at Night initiative, which essentially crowdsources light pollution data collection. The Highland Park Road Observatory hosts periodic training sessions for people who want to learn how to report information about their own areas through the program. In addition, BRAS has added a light pollution extension to their website, which has information on types of light pollution and tips for making a stargazer’s backyard as dark as it can be.
What are we losing up there?
In a world with plenty of problems on the ground, we might be forgiven for concluding that a lack of visible stars in the sky is the last thing we should worry about. But in the grand scheme of our species, it’s worth noting how far we’ve come because we could see the night sky.
As early as 2000 B.C., the Indus Valley civilization was using the night sky to create calendars. Stonehenge was built to line up with the sun and moon, and many other early civilizations based spiritual beliefs on celestial movements. Galileo turned a modified spyglass—later called a telescope—to the sky and found that, contrary to contemporary understanding, the moon and stars were made of different stuff, that Jupiter had moons, and that Earth traveled around the Sun. Sir Isaac Newton used Kepler’s Laws of Planetary Motion to derive his Three Laws of Motion and the Law of Universal Gravitation, which provided formulas to calculate motion of objects in the heavens and on Earth, from comet trajectory to ocean tides. We would never have left our planet without these observations.
[Read this: How Louisiana's LIGO helped prove gravity.]
Perhaps when one gazes upward long enough, our entire history stretches out in that rarely-visible arm of the Milky Way. When I asked the LPC about the philosophical value of what we’re losing up there, one committee member pointed across the table at Scott Cadwallader.
“The stars have been with us basically since the dawn of time,” Cadwallader began. “They encourage us to travel across the seas; they mark the changing of the seasons; they told people when to plant their crops. They speak to the heart of man, to man’s curiosity, and the human propensity toward seeking the unknown. As chance would have it, it just happens to be infinite.
“Some of our early forays into mathematics were trying to understand the movements of the stars. I think it even goes back to what touches the heart of the religious spirit in man. There’s this line somewhere in [the Book of Genesis], where they talk about, ‘You may as well try to count the number of stars in the sky.’ What it originally meant was countless, like the stars. But we can’t understand that anymore, because I can go out and count them. There’s three hundred and twenty.”
Learn more about light pollution on a local level in the Dark Sky Advocacy section of the BRAS website, at brastro.org.
Other light pollution resources can be found in abundance at darksky.org.
For a full schedule of this month’s stargazing events at Highland Road Park Observatory, visit hrpo.lsu.edu.
Help crowdsource data on light pollution in your area by participating in the Globe at Night initiative, at globeatnight.org.
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