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Steve C. Petzold: Stars up and Lights down

Environmentally Speaking

Posted: June 14, 2012 2:00 a.m.
Updated: June 14, 2012 2:00 a.m.

As an amateur astronomer and concerned citizen, I have seen a gradual deterioration of our night sky due to light pollution, since moving to Santa Clarita 12 years ago. 

Within the past few months, the counties of Kern and Los Angeles (in the rural areas) have passed ordinances to control  the deleterious effects of light pollution in these important areas. 

While there are a number of working definitions for light pollution, the one that I find most helpful is that used by the International Dark-Sky Association. Light pollution is, “any adverse effect of artificial light including sky glow, glare, light trespass, light clutter, decreased visibility at night, and energy waste.”

“Stars Up/Lights Down!” has become the rally cry for a number of groups which have been organized to educate citizens, opinion makers and politicians about light pollution in an effort to influence individual behavior and public policy.

Many times, these efforts have been led by astronomers who want to protect the night sky for enjoyment or scientific research. However, dark sky preservation, enhancement or renewal is not a narrow parochial interest. The benefits of smart, proper and efficient lighting design accrue to a broad range of interests within a community.

As society has looked towards energy conservation, a point of focus has become energy wasted due to poor lighting design.

It has been estimated that 30 percent of outdoor lighting is wasted due to poor design. Many times, the lighting is excessive, the lamp source may be improper, or fixtures cast light out beyond the area intended because they are not properly shielded.

Billions of dollars and natural resources are wasted generating electricity which is not used effectively. Many environmentalists are concerned about the carbon dioxide released into the atmosphere that they believe affects climate change.

Light pollution has a negative impact on wildlife. It is well-documented that urban lighting has disrupted the migration patterns of birds. 

For those of you who ask the question, “Why don’t the geese migrate from Bridgeport?” the answer may be that they cannot find their way home.

Nearly half of the world’s species are nocturnal, and light pollution can be as devastating to their breeding and feeding patterns as an earthmover.

In Florida, very strict lighting ordinances are enforced in beach areas to protect hatching turtles that migrate inland toward artificial light rather than to the ocean, increasing their mortality rate. 

When it comes to human health, research has consistently shown a negative affect by excessive lighting. Our circadian rhythm is essential to remaining healthy.

Too much artificial light can disrupt this pattern, interfering with essential hormone production (melatonin), affecting our essential sleep.

Harsh glare from acorn style and drop lens luminaries used to illuminate streets reduces our night vision, especially for seniors who drive. Recently, it has been discovered that light pollution has a negative effect on air quality.

The National Oceanic and Atmospheric Administration (NOAA) reported in 2010 that light pollution in Los Angeles reduces the natural production of a nitrate radical that breaks down car exhaust and other human produced emissions during the night hours.

As a part of their summer “Night “reading series, the Valencia library will be presenting an award winning documentary by Ian Cheney, “The  City Dark…In search of darkness on a planet that never sleeps!”

This film is both entertaining and informative as it examines the issue of light pollution, the dangers it presents to humans and wildlife, and the effort to make effective changes to benefit our world.

The program will be in the meeting room of the Valencia library today, starting at 6:30 p.m. with a guest speaker. At 7 p.m., the documentary will be shown (with the lights off) and the running time is 84 minutes. For information visit or contacting the library at 661-259-8942. The program is appropriate for children and adults.

Progressive individuals and political entities around the world have begun the process of addressing the issue of light pollution. A dark sky which reveals the majesty of the heavens above is a primary and ancillary benefit to the myriad reasons to implement proper lighting design and usage.

It is as important as the creation of wildlife corridors and ridgeline preservation. Let us begin the process of limiting light pollution in Santa Clarita by attending tonight’s event and educating ourselves.

The process begins by remembering the simple phrase: Stars Up/Lights Down!

Steve Petzold is an noted amateur astronomy geek in the Santa Clarita Valley 


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