Have you looked up at night lately? The universe is going away, gone already for many.  The universe is an important part of the environment, to astronomy and to the general public.

For most people on earth, the dark skies our ancestors had have disappeared.  The problem is urban sky glow, due mostly to too much bad lighting.

With good lighting, we all win.  We help preserve the dark skies, we see better (and are safer and more secure), we have a more pleasant and comfortable nighttime environment, and we save a great deal of energy and money doing so.  Neither astronomers nor the public, anywhere, need any of the adverse environmental effects of poor lighting.
 

Open your eyes to the nascent glow,
Watch as it starts on the horizon low.

As twilight deepened, the lights did come,
Another ton of coal's job is done.

In country the celestial show delights,
Tis only a dream of longing suburbanites.

Youngsters wonder of Milky Way lost,
Old man knows how much the cost.

Cruel fixtures that live in the night,
Takes the stars from our sight.

Comets die, northern lights disappear,
We have lost much of what we once held so dear.

• Urban sky glow (the brightening skies over our heads), destroying our view of the universe.  We don't live up there in the sky; we don't need all that light up there.

• Glare.  Glare never helps visibility, but it is far too common in all of our cities. We should strive for a glare free environment.

• Light trespass. Many present lighting installations bother us as much or more than they help.  The wasted light shines into our yards, our windows, even our telescope buildings.  As with noise pollution, we don't need any of this bad light.

• A trashy looking, confusing nighttime environment.  We should, all of us, be striving for a good looking nighttime environment, just as we should be doing in the daytime.  Such poor environments are part of the stress of today's life.  We should help with the problem, not compound it.  Remember, the night is part of the environment too.

• Energy waste.  We waste an astronomical amount of energy and money by all this bad lighting, shining it where it is not needed or wanted (including up into the sky) and by using energy inefficient light sources and lighting designs.  Better to use such money for improving our world, not mucking it up.

"If energy efficient lighting were used everywhere that it was profitable, the electricity required for lighting would be cut by at least 50 percent.  This reduction would free $18.6 billion from rate payer bills for useful investment and reduce annual carbon dioxide emissions by 232 million tons, the equivalent of 42 million cars."

So What To Do?
 

• Use good lighting. Such quality designs are really all just common sense approaches to lighting.  Let's not tolerate all the bad lighting; let's get rid of it.

• Shine the light down, where it is needed.  Control the light output to locations where it is needed; don't waste it.  Use quality lighting fixtures.

• Use time controls (or dimmers or other controls) to insure that light is there when needed, and not there when it is not.

• Design and install lighting to insure that glare is minimized.  Most all glare comes from poor fixtures or poor installations.  There is no need for any of it.

• Use the right amount of light for the task, not overkill.  "More light" is not the approach to use. When not blinded by glare, the eye is a marvelous instrument and can see very well at what seems to be quite low lighting levels.  In addition, going from over lit areas to darker areas means that we don't see too well (transient adaptation), and the opposite holds as well.

• Use energy efficient light sources.  Light sources vary greatly in their efficiency. Consider especially the use of low pressure sodium lamps; they are the most efficient of all, and they are also strongly preferred by astronomers as the light output by LPS is essentially all one color and can be filtered out quite well.  LPS is excellent for street lighting, parking lots, security lighting, and other applications where color rendering is not critical.  Careful lighting design can be done using LPS for essentially any application.

One way to effectively begin is for cities to appoint an Outdoor Lighting Working Group to consider the issues and to recommend specific solutions (including lighting control ordinances) tailored to local needs.  Such "committees" have been quite effective in a number of locations. Most of those active in both the astronomy and the lighting communities appreciate the advantages of good lighting and are eager to help implement them.  Organizations in both these communities have committees on this topic.
 

So What's the Problem?

The main problem is that there is still a vast lack of awareness of the issues, the problem, and the common sense solutions.  Education is the main thrust of most current activities. The second large problem is apathy.  Even with awareness, action is needed. Some consider it too big an issue to become involved with, other feel that it is not important enough.  Neither is a good enough reason for apathy.

Lighting accounts for 20 to 25 percent of the electricity used annually in the United States. Lighting for industry, stores, offices, and warehouses represents from 80 to 90 percent of the total lighting electricity use.  If energy efficient lighting were used everywhere that it was profitable, the electricity required for lighting would be cut by at least 50 percent.  This reduction would free $18.6 billion from rate payer bills for useful investment and reduce annual carbon dioxide emissions by 232 million tons, the equivalent of 42 million cars.  It would also reduce sulfur dioxide emissions by 1.7 million tons and nitrogen oxide emissions by about 1million tons.  Other forms of pollution ash, scrubber waste, acidic drainage and waste from coal mining, radioactive waste, and natural gas leakage would also be reduced, of course.

Example of Cost Comparison: (Assume that a well designed fixture is being used in these cases, so that the light output by the lamp is not wasted by an inefficient fixture.  A bad fixture could be wasting more than 50 percent of the lamp's light.)  Compare a 175 watt mercury (These are generally found in poor fixtures!) to a 100 watt HPS and a 55 watt LPS lamp.  All of these lamps are outputting about 8000 lumens, quite a lot of light.  They are wattages that would commonly be used for residential street lighting.  We assume 4100 burning hours per year, from dusk to dawn, and 8 cents (U.S.A.) cost per kilowatt-hour (KWH) of use.  The total wattage of the system includes the wattage used by the lamp and the ballast together.  It is easy to see the potential saving gained with efficient lamps.

Lamp Wattage  Total Wattage  KWH Use/Yr   Oper $/Yr   100 lamps
        175                 208                853              $68.22         $6822
        100                 130                533                42.64           4264
         55                    80                328                26.24           2624