How Light Pollution Distorts, Dilutes and Destroys the Night Sky

When most people consider pollution, they contemplate the impact of tangible environmental deterioration – refuse lining a sidewalk, plumes of automobile exhaust hazing over a highway, or industrial sludge pouring into a river. Such matter-based pollution causes incalculable and permanent damage to natural ecosystems while detracting from the safety, livelihood, and health of communities both rural and urban.

However, while these forms of contamination pose devastating consequences for humanity and nature alike, another category of pollution threatens to obscure the rest of the universe from earth’s gaze. Without weight, smell, or texture, light pollution represents one of human civilizations greatest wastes of resources as well as one of its most under-acknowledged detriments to the globe.

From trillions of fixtures worldwide, artificial light bathes the streets, parks, commercial centers, and neighborhoods of our society each evening. Humans usually regard large-scale outdoor lighting as one of the greatest achievements of the past century. Casting aside the inconsistent and dangerous flicker of candles, torches, and lanterns, electric lighting has allowed cities to flourish, transportation to accelerate, and humanity to venture into the night. Thomas Edison’s invention of the incandescent light bulb stands both as a milestone to the fortitude of the great scientist’s mind, and to an age of global inquiry and innovation. Today, artificial lighting shines on all seven continents and into the most vaunted intersections of human history – the lights of Paris, New York, and Las Vegas have woven their beams into the worldwide cultural cannon as symbols of sophistication, enterprise, and revelry respectively.

However, like all other human innovations, at what point does artificial lighting
impinge upon nature and begin to detract from our collective habitat? With countless trillions of wattages flowing through countless trillions of filaments, what constitutes a waste of energy? At what point does artificial lighting begin to undermine the natural rhythms of earth’s solar cycles? At what cost has man domesticated the night?

What is Light Pollution?

Since light pollution resides in a realm more ethereal than physical, people have only begun to fashion rudimentary definitions. The Institute of Astrophysics of Caneries defines light pollution as:

The sky glow produced by the scattering of artificial light in the gases and particles of the air caused by poor quality of outdoor lighting. These poor fixtures send part of the light up to the sky instead of down. This also results in light trespass, glare and energy waste.

Frank Morgan, a pollution activist, maintains that light pollution is:

The emission of artificial light into areas where it is unneeded or unwanted. It is caused by obtrusive outdoor lighting (residential, commercial, or other) that wastefully casts light upward into the sky or into the horizontal plane. Any fixture that shines all of a portion of its light to the sides rather than toward the ground pollutes the sky, or perhaps a neighboring yard or window, with excess light.

In his essay, “Where has the Night Sky Gone, and Why Should We Care?,” Cliff Haas writes:

Light pollution in the simplest terms is the result of too much wasted light. It has been estimated to cost the United States well over a billion dollars per year for the electricity generated to send light into the sky and across property lines where it serves no benefit.

Regardless of whether one chooses to define light pollution by its chemical properties, engineering specifics, or fiscal waste, most descriptions center around the notion that almost all fixtures cast some amount of unneeded and unwanted light toward the ground and sky. Such luminary excess stands as the root cause for light pollution and its environmental detraction.

The New England Light Pollution Advisory Group (NELPAG), a grass-roots organization founded in 1993, follows this hypothesis by claiming that light pollution stems from three central causes:

NELPAG elaborates upon each of their points by offering individual scenarios involving light pollution and potential solutions. On the road, for instance, NELPAG believes that most highways do not need artificial lighting and that the vast majority of lights presently in place are so bright that they actually induce glare, a disorienting streak of light which hinders the vision of motorists. As a solution, NELPAG and numerous other groups propose the installation of plastic covers to shield light downward, thus preventing glare and excess energy waste while mitigating the effects of artificial light on the surrounding environs.

Though this solution seems sensitive and thrifty, light pollution interest groups have had only limited success persuading highway agencies to install light covers and practically no success in convincing anyone to dim or remove lights. Perhaps the reason for this disjunction resides in the reality that very few people understand the extent to which light pollution can destroy a region.

How is Light Pollution Harmful?

While its definitions remain general and even philosophical, the repercussions of light pollution remain very real. For example, consider this chilling anecdote excerpted from “Where has the Night Sky Gone, and Why Should We Care?”:

In the 1970s, the US Department of Agriculture noticed that dusk to dawn lighting from a high-pressure sodium lamp was affecting young sycamore trees. (The light) confused their seasonal rhythms causing sap to remain in the leaves and branches too long. They dropped their leaves too late, frost came and the cold of winter soon followed. The following spring many of the year old saplings perished.

Such a case study surely attests to the unnatural effects of artificial lighting while offering a snap shot into one specific impact of light pollution. Other examples in nature involve birds, squirrels, and chipmunks who tell time by light levels, and thus have their entire life cycles thrown out of loop by high-powered artificial lights. Every year, thousands of sea turtles are dashed to death on costal highways. The turtles confuse the lighted roads for the moon’s reflection on the ocean and walk toward them when they should be swimming out to sea. Countless case studies abound to show the detriments withstood by other species of flora and fauna, however the impacts upon humans are heavily significant as well.

For years, the power utility companies and other corporate interests have fostered the notion that communities need more artificial lighting than they actually do. Often the utilities will argue that bright lighting is safer both for pedestrians and motorists, when in fact studies have shown the opposite. The glare produced from excess artificial light often hinders a nighttime driver’s vision to the same degree as if he or she were driving into a setting sun. Glare has also been shown to induce a light scattering effect in the eyes of senior citizens, and to a lesser degree in those who wear artificial lenses. Furthermore, despite an unfounded consensus that bright artificial light discourages vandalism and violent crime, most studies actually show a significant correlation between light pollution and night crime.

Another subsidiary issue of light pollution involves the problem of light trespass, the altogether too common phenomenon wherein light from one property, commercial, industrial, or residential seeps onto adjoining properties. Light trespass lowers the quality of life for residents everywhere and particularly for those who live near centers of commerce, parking lots, and highways. Similar to noise pollution and other intangible annoyances, light trespass disturbs the tranquility of neighborhoods and prevents a fair percentage of the population from attaining a decent night’s sleep. Court decisions have affirmed this interpretation, and have ruled on light trespass cases in a similar fashion to cases involving excessive noise disturbances.

While elected officials and utility executives continue to debate these points, no one can ignore the two largest and most indisputable impacts of light pollution. The first of these entails the tremendous waste of money and energy expended upon excess artificial lighting. N.E.L.P.A.G states that the average Massachusetts town of 25,000 to 30,000 citizens spends up to $500,000 a year on lighting costs alone. At a time when fossil fuel sources have become a violent point of contention around the world and alternative energy sources have yet to meet large scale success, such a figure should provoke concern in officials in the state and federal government, not to mention outrage in the average taxpaying citizen.

The second indelible impact of light pollution involves our sightlines into the universe. Namely, through the emission of excess luminary particles, light pollution has begun to blot out the night sky under a bright haze. Over the last 50 years, these clouds of light have detracted heavily from our view into the celestial evening, much to objection of naturalists, stargazers, and even NASA, who says that light pollution represents one of its most persistent obstacles in studying the galaxy. With dark adjusted eyes, people should be able to see between 2,600 and 10,000 stars on a clear evening. However, due to light pollution, one can generally only hope to see several hundred stars at best.

While amateur astronomy clubs, universities, and public observatories have produced some of the most vocal and informed opposition to light pollution, every inhabitant of the planet should feel concern for lost stars. Painters, philosophers, and poets have all drawn inspiration from the stellar well of the night sky. Consider this poem, “When I Heard the Learn’d Astronomer,” by Walt Whitman:

When I heard the learn’d astronomer,
When the proofs, the figures, were ranged in columns before me,
When I was shown the charts and diagrams, to add, divide, and measure them,
When I sitting heard the astronomer where he lectured with much applause in the lecture-room,
How soon unaccountable I became tired and sick,
Till rising and gliding out I wander’d off by myself,
In the mystical moist night-air, and from time to time,
Look’d up in perfect silence at the stars.

Whitman’s poet liberates the sky from any mathematical or scientific pretense, and demonstrates how anybody can appreciate the splendor of a clear evening, and the billions of miles inherent in that gaze. How many of us can sympathize with the calm release of the poet’s narrator, as he/she steps out into the night? One need not a degree in astrophysics to appreciate such a sight, nor such a mind to recognize the impending threat of light pollution dimming the sky permanently.

What are the Solutions to Light Pollution?

Light pollution represents a local problem on a global scale. Thus, potential solutions to light pollution entail both personal responsibility and external activism. In other words, those with an interest in limiting luminary excess should tend to the affairs of their backyards before tending to those of the local municipality and state.

At home, a number of simple solutions exist to limit residential light pollution. The following are a list of recommendations from N.E.L.P.A.G. and the International Dark-Sky Association Incorporated and other light pollution activist groups:

Once you have converted your own property into an energy efficient light pollution-free zone, it is logical to then consider methods of alleviating the problems of excess light in the community. When embarking upon this enterprise, information is your best ally. Consider researching the websites listed at the end of this article for pertinent light pollution information.

Armed with information, the next step is to contact local groups with a direct interest in regional light pollution issues. Colleges and universities, observatories, and astronomy clubs are excellent places to learn about light pollution and to network with concerned citizens searching for answers. Once introduced to these groups, ascertain any relevant schedules of events and determine how the group has taken an active stake in local politics through township, borough, and municipal meetings. While many budding light pollution activists may be tempted to petition the federal government, the truth remains that a local supervisors meeting holds far more promise for affecting change than writing a congressperson.

When addressing local government, it is best to avoid confrontation but rather to suggest sensible alternatives to light systems and arrangements. Keep any presentation centered on the issues of safety, wasted energy and money, and the immediate environmental repercussions of light pollution. It may be effective to close a light pollution discussion with a loquacious overture to the celestial splendors lost, but keep the meat of your argument grounded on local issues. For a more in depth discussion on light pollution and local government, see Warren Offutt’s essay, “Solving Neighborhood and Light Pollution Problems.”

Some of the efforts of light pollution activists groups have resulted in proposed and enacted legislation. In the states of New Hampshire and Massachusetts, citizens have proposed codes for lighting design and luminary output levels to limit the impact of light pollution on their communities. These codes and others address the chemical categories of different light fixtures with recommended shields. For instance, the proposed New Hampshire code stipulates that High-Pressure Sodium and Metal Halide lamp fixtures require full shielding and that mercury vapor and quartz lights are to be banned altogether. Other sections address zoning and light trespass issues.

Recently, Maine became one of the first states to adopt such proposed legislation into law. Under section 23 of the state highway law, Maine’s ordinance sets upper limits on light output levels while promoting efforts to prevent glare. This statewide sanction lends further credibility to light pollution prevention while giving the cause a resounding success story.

On Return to a Dark Night: Closing Thoughts on Light Pollution

This essay has expounded upon the causes, effects, and global repercussions of light pollution. With opinions, personal ordinances, and commercial venture pulling in diverging directions, the burden of responsibility to win back the night rests with the reader.

For a fight that has had little exposure, let alone success, inspiration for potential activists is at a premium. Perhaps the textual sparseness of this closing passage can act as a model to minimalist efficiency – the same configuration dynamic needed for efficient artificial light design. With this approach, diligent citizens can, amongst other things, win back the night.

Links

The International Dark-Sky Association Inc.
This site offers a considerable amount of information on the origins of and solutions for light pollution.

The New England Light Pollution Advisory Group
For ten years, this grassroots community group has disseminated information regarding light pollution to the public and elected officials.

Illuminating Engineering Society of America
The continent’s, “Lighting Authority.” Offers specific information on light pollution problems and prevention.

Where has the Night Sky Gone and Why Should We Care?
Presented at the 2000 World Congress on Managing and Measuring Sustainable Development, Cliff Haas’ passionate essay has become a standard in the light pollution activism community.

Solving Neighborhood Light Pollution Problems
This site includes an essay by Dr. Warren Offutt on how to inform and persuade officials from elected state representatives to local homeowner’s associations on the problems of light pollution.

Model Ordinances

Below is a listing of lighting ordinances for reference. We are not recommending any particular ordinance but rather suggest that you review a number of them and merge the concepts presented into one that suits the needs of your community. We would further suggest that particular attention be paid to residential “security” lighting as this is an area that is often overlooked but can be as severe a problem as commercial lighting.

http://home.epix.net/~ghonis/ordinanc.htm

http://www.volt.org/VOLT%20Model%20Ordinance%20v4.html

http://www.skykeepers.org/ordsregs/califord.html

http://icole.home.att.net/ind_ord.html

http://home.att.net/~icole/ord_framework.html

http://www.physics.emich.edu/sherzer/nolites.html

http://www.delapp.com/codes/ltgordinance-taos.php

http://cfa-www.harvard.edu/~graff/nelpag/ordbylaw.html

http://www.darksky.org/ordsregs/usamunis.html

http://www.dancaton.physics.appstate.edu/NCDarkSkies/HCOrdinances.htm

http://www.resodance.com/ali/uni_ords.html

http://www.darksky.org/handbook/lc-hb-v1-13a.html