Light Pollution: The Problem, The Solutions
Abstract:Â The problem of light pollution exists most everywhere, and it is still growing rapidly.Â Fortunately, there are solutions. The problem is a lack of awareness, including within the astronomical community. There is a great deal of apathy and inertia to be overcome as well. However, progress is being made in a number of places. The astronomical community must become much more involved if we are to preserve the quality of our nighttime skies, both for research and for the public. The beauty of the night sky is a wonderful thing to all. In addition, everything done to decrease the adverse urban sky glow also helps greatly to improve the quality of night lighting. With good lighting, we improve visibility, safety, and security, as well as minimizing energy waste, and we have a much more comfortable nighttime environment. There are resources to help, within the astronomical community and the lighting industry, and these are growing. The International Dark-Sky Association has a great deal of information that is most helpful; see the Web site at www.darksky.org.
For most people on earth, including we professional astronomers, the dark skies our ancestors had have disappeared. The problem is urban sky glow, due mostly to too much bad lighting. It has adversely affected most all of our observing sites. And it is still getting worse in most locations.
There are solutions to the problem, but a key point is that we must join together in our efforts in attacking all this bad lighting, encouraging the use of only good nighttime lighting for all applications. With good lighting, we all win. We help preserve the dark skies, we see better at night (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. We should not tolerate it. We must do all we can, individually and organizationally, to preserve the beauty of the night sky, for astronomy and for all of mankind!
II. The Problem
There are many good reasons for artificial lighting at night: to help us see better, for security, safety, utility, and for an attractive nighttime environment around us. There is no way that nighttime lighting is going to disappear, even if there is another energy crisis. There are too many good reasons for such lighting. But not all lighting is good lighting. Far too much of our present nighttime lighting does not meet its objectives. It is bad lighting. Let me list here the common components of bad lighting:
- 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. It is a problem both for astronomers and for the general public, most of whom really enjoy the beauty of the night skies. It has been growing most everywhere, and it has severely impacted operations at many existing observatories. In those locations where it has not yet, you can be sure that it will in time, if we are not able to implement solutions. This sky glow has also removed the view of the universe from most of the public, the majority of which are urban dwellers. It would be a crime if our children and their children lose all of their view of the beauty of the night sky.
- Glare. Glare never helps visibility, but it is far too common in all of our cities and in most lighting everywhere. We should strive for and accept only a glare free environment. Let's not be blinded by glare. Far too much present day lighting has glare; it is always bad.
- 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 these intrusions. Such lighting is not meeting well the goals for which is was installed.
- A trashy looking, confusing nighttime environment. We should, all of us, be striving for an attractive 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 trashing it. In the United States alone, over One Billion Dollars is wasted every year just to light up the night sky.
III. There Are Solutions
We all suffer from these problems. But we need not, for fortunately there are solutions. The key is quality nighttime lighting. Let me list briefly the components of these solutions.
- Use only 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 good design. 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 since 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.
IV. Progress in Implementing Solutions
Quality lighting design is being used now in many locations, such as Tucson. Such cities are benefiting by better lighting for their citizens, by a great deal of energy savings, and by darker skies (but not darker streets). We all really do win. Awareness of the problems and of the solutions is increasing rapidly, in the public area and especially in the lighting community.
The International Lighting Commission (CIE) and many national organizations now have technical committees addressing the issues, and reports and recommendations are pending. After all, who can be against good lighting rather than bad, given all its advantages? I am an active member of most of these committees, and I am pleased with the growing awareness and activities.
One effective method for communities to attack the problem is to appoint an Outdoor Lighting Working Group to consider the issues and to recommend specific solutions tailored to local needs (including lighting control ordinances to set community standards; hundreds of these have now been enacted). Such "committees" have been very effective in all locales where they have been implemented. They have the added advantage of educating many people about the issues.
VI. So What's the Problem?
The main problem is that there is still a vast lack of awareness of the issues, the problems, 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, others feel that it is not important enough. Neither is a good enough reason for apathy. Most astronomers are doing little or nothing to educate themselves about the issues, much less to spend time working for solutions.
VII. Help Is Available
The International Dark-Sky Association, a non-profit organization, is a powerful ally to help anyone with their educational efforts. It is a membership-based organization with over 2000 members now from 70 countries. IDA has produced over 130 information sheets discussing the issues, and they are an important resource for those who want to become informed and who want to help spread the word to others. Check out IDA's Web site on the Internet (http://www.darksky.org) which contains a lot of excellent information about the issues and links to many other interesting sites. While there is a growing awareness of the problems, and of the solutions, much more educational outreach is needed. IDA needs many more individual and organizational members and much more support from the astronomical community, nationally and internationally.
There is a problem with light pollution, for astronomy and for the public, and it is still getting worse most everywhere. However, there are solutions, and they work. They also improve the quality and effectiveness of our nighttime lighting, and they help us save a great deal of energy and money. We know that for sure. Lack of awareness and apathy are the main problems. Action is called for. Now. By all of us. The bottom line is that "We All Win."
Please do help build awareness and overcome apathy, everywhere. The stars and the universe need the support of us all. Join with us to help preserve mankind's view of the beauty of the night sky!
Â David L. Crawford
The above content is an extract from the IDA Information sheet# 134. All writing courtesy of the IDA.
For more on the IDA and ideas and solutions, visit the IDA website.