Light Pollution — Theft of the Night - International Dark-Sky ...

International Dark-Sky Association (IDA) — Information Sheet #90
Light Pollution — Theft of the Night
I. Introduction: 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.
II. Why night lighting? To see at night, for security,
safety, utility, and for an attractive nighttime
environment around us. But not all lighting is good
lighting.
III. What are the adverse impacts of poor nighttime
lighting?
A. Urban sky glow (the brightening 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.
B. Glare. Glare never helps visibility, but it is far
too common in all our cities. We should strive
for a glare free environment.
C. Light trespass. Many present lighting installations
bother us much 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.
D. 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
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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.
E. Human Health and Ecology. Recent
research has made it clear that we must take
into account the fact that electric lighting affects
more than vision. There are numerous photobiological
aspects to light, with both positive
and negative impacts on humans and on the
ecosystem.
F. Energy waste. We waste an astronomical
amount of energy and money by all this bad
lighting, shining it where it is not needed nor
wanted (including up into the sky) and by using
energy ineffi cient light sources and lighting
designs. Better to use such money for improving
our world, not mucking it up.
We all suffer from these problems. But we need
not.
IV. So what to do?
A. 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.
B. 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
fi xtures.
C. Use time controls (or dimmers or other controls)
to insure that light is there when needed,
and not there when it is not.
D. Design and install lighting to insure that
glare is minimized. Most all glare comes from
poor fi xtures or poor installations. There is no
need for any of it.
E. 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 continued
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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.
F. Use energy effi cient light sources, Light
sources vary greatly in their effi ciency. Consider
especially the use of low pressure sodium
lamps; they are most effi cient of all, and they
are also strongly preferred by astronomers as
the light output by LPS is essentially all
one color and can be fi ltered 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.
V. It all works! Such quality lighting design has
been used for some time now in many locations.
Such cities are benefi tting 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.
One way to effectively begin is for cities to
appoint an Outdoor Lighting Working Group to consider
the issues and to recommend specifi c 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.
VI. 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.
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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.
VII. Help is available. The relatively new International
Dark-Sky Association, a non-profi t organization,
has been formed to help with the educational
efforts. It is a membership based organization with
members now in 70 countries. IDA has produced
many information sheets discussing the issues,
as well as slide sets and other material available
for those who want to become informed and
who want to help spread the word to others.
Check out IDA’s web page on the Internet:
http://www.darksky.org. There is a slowly growing
awareness of the problems, and of the solutions,
but much more educational outreach is needed.
VIII. Conclusion. There is a problem, and it is still
getting worse most everywhere. However, there
are solutions, and they work. They also improve
the quality of our nighttime lighting, and they
help us save a great deal of energy and
money. Lack of awareness and apathy are
the main problems. Action is called for.
The conclusion is that: WE ALL WIN.
IX. Thanks! Please do help us build awareness
and
overcome apathy, everywhere. The stars and the
universe need our help. Help us save the stars!
Join us as a member!