Reclaiming Starry Nights: A local campaign to reduce light pollution
Posted by collegegreenou on December 11, 2009
By Swati Ramanathan
One of the unique and enduring pleasures of humankind is the ability to gaze up at the night sky in rapt wonder. Astronomy was the television of its day, with the stars and moon providing most of the night-light required by our ancestors. Finding patterns in the stars and familiarizing yourself with the night sky was your best bet at predicting seasons. Planting crops and harvesting them at the right time was a crucial aspect of early agriculture. To this day, most harvest festivals around the world use astronomical calendars, including Easter, which is said to have its roots in a pagan fertility festival (‘harvest’ and ‘fertility’ are often used interchangeably when referring to festivals, to represent the concept of land fertility). Even though they’re lightyears away, it’s easy to see that the stars have had a tremendous impact on human civilization.
If you live in a city, however, you are deprived of the starry night in its full glory. It’s hard to perceive the faint band of the Milky Way, a sight familiar to our ancestors, particularly in the Northern Hemisphere. You have probably never noticed that one of the ‘stars’ in the Orion constellation is actually a nebula. City lights are bright and will overwhelm all but the brightest objects in the night sky.
Most people erroneously believe that there is a direct correlation between bright lights at night and safety. This is simply not true, with most studies concluding that there is no relation between any kind of lighting and crime. So overall, bright lighting has no real benefits and some distinct disadvantages such as over-illumination.
Over-illumination is just one form of light pollution. There is also light trespass, which occurs any time light from your neighbor’s home bothers you to the point where it affects the quality of your life (for example, by disrupting your sleep). Blinding glare from streetlights is another aspect of light pollution, which can be especially dangerous to drivers. Finally, there is skyglow, the reddish glow around big cities, caused when reflected light from poorly shielded light fixtures is scattered by the atmosphere, reducing contrast between the sky and the stars and making ground-based astronomy extremely difficult.
Each form of light pollution can affect our quality of life. Circadian rhythms, the internal biological clocks in humans and most animals, are regulated by light and roughly follow the earth’s daily rotation. An important aspect of these rhythms is the antioxidant melatonin, which is produced in the absence of light. Research shows that melatonin production is linked with strong immune responses, increased longevity, reduced risk of cancer, migraine and brain injury. Conversely, a decrease in melatonin brought about by too much light robs you of these benefits.
Over-illumination is not only unnecessary and unhealthy but also expensive. Australia has government case studies of such expenses, where public lighting accounts for between 30 and 50 percent of greenhouse gas emissions and costs $195 million (USD) annually. One study of the city of Coff’s Harbor (pop. 70,000) estimated that by switching to more efficient and reliable lighting, they could reduce CO2 emissions by 35 percent and rack up a 10-year cost savings of $640,000 (USD).
A Local Campaign
Half a world away in Athens, Ohio, some residents have already recognized the importance of the issue of light pollution and have begun to address it. The effort to reduce excess lighting was spearheaded by Dr. Joe Shields, an astronomer and chair of the Ohio University Department of Physics and Astronomy. Pursuing this effort was imperative for him both as an astronomer and as a resident of an area that advertises its clear night skies.
Shields’ efforts began in 1999 when he talked to the mayor and the Athens city planning boards. When he found that the city was due for a zoning code revision, he did the necessary research and studied other places where light pollution laws were implemented. He formulated a draft, which was presented to the city planning board. The board, Shields says, was very receptive to the idea. The zoning ordinance was passed in 2003, addressing light pollution, glare and light trespass. The ordinance affects outdoor lamps/luminaries rated at above 1800 lumens and all spot lights rated at above 900 lumens, and dictates that they shall not emit light above a horizontal plane. In addition, lighting is to be designed to minimize illumination of adjacent lots and streets. This ordinance is subject to a grandfather clause and only applies to new private lighting.
The city of Athens contracts with American Electric Power for its street lighting needs, making it rather difficult to estimate the energy/cost savings of efficient lighting. The good news for Athens, however, is that AEP now offers a larger suite of well-designed light-fixtures than it had in the past. Ohio University is exempt from this local ordinance, but has nonetheless also responded well to calls to switch to more efficient light fixtures.
From the year 2000, the Southeast Ohio Astronomical Society and the Ohio University Department of Physics and Astronomy have jointly given out an annual ‘Friend of the Stars’ award that recognizes excellence in outdoor lighting. The Athens City Council was a recipient of this award in 2004, for passing the zoning ordinance. Shields received the 2005 award for his efforts to reduce light pollution locally. Wal-Mart, the Athens Community Center and O’Bleness Hospital are all great examples of good outdoor lighting that have also received this award.
It took the efforts of a few concerned local residents to address the growing issue of light pollution in Athens, a problem that many larger cities have yet to tackle. The ordinance is a small step, but an important one. The ability to see objects as far as our eyes can see at distances our minds can barely grapple with is but one of the reasons to preserve our night sky. Tracing imaginary patterns in the stars and weaving elaborate tales around them has been a unique pastime common to all of humanity. The stars give us perspective, and show us our place in the universe. Clouds notwithstanding, the right to a clear night sky is a basic one, worth fighting for.
Editor’s Note: Swati Ramanathan is a graduate student in the Condensed Matter (CMSS) section of the Department of Physics and Astronomy.