1998 Sept. 9
To the Editor, Providence Journal:
I have heard through the Boston Globe and the Internet (including your
own web site) about the "Illuminate Providence" proposal, and I'd like to
shed a different type of light on this glaring idea. Many, many people in
the world -- including many in the Providence area -- enjoy the night-time
environment without artificial lights permeating everywhere. Have you so
quickly forgotten those wondrous sights that we were able to see in the
last couple of years -- naked-eye comets known as Hyakutake and Hale-Bopp?
Or how romantic a stroll under the stars can be? Surely our children deserve
to see stars at night from their homes, just as they can see trees and
birds in the daytime. But our ever-increasing use of outdoor lights in
urban and rural areas alike is stealing away the natural wonders of the
night, and this is an incalculable loss to our civilization. It is becoming
harder and harder to escape from manmade controls and effects in our daily
(and nightly) lives, and this effectively gives us less independence.
It is a myth that more light reduces crime. In fact, I can cite
cities and towns across the United States that have actually turned off
lights (to reduce crime or to save taxpayer money for other purposes),
where police officials report that pre-existing crime rates either
plummeted or remained unchanged. Other police officials note that glary
security lights can promote crime and be potentially dangerous to police
officers, as criminals can actually hide in the shadows and be invisible
because of the glary light pointing out in all directions. And a recent
survey published in USA Today placed dogs, alarms, moving to a safer area,
and having someone at home all as deterrents that were ranked above
lighting by prison inmates convicted of property crimes.
Having said that, I note that there are good uses for thoughtful
outdoor lighting, such as around important street intersections. But
we have been too thoughtless by permitting lights to be erected that
are unshielded, permitting their glary light to stream out dangerously
into the eyes of motorists, pedestrians, and cyclists, and to invade
bedroom windows at night or the yards of amateur astronomers, young
and old. Bad, glary lighting can and does cause accidents and promote
crime. Thoughtful, full-cutoff lighting (where light is not emitted above a
horizontal plane cutting through the bottom of the lamp) is becoming very
popular around the country and the world as an aesthetically-pleasing
and energy-efficient way of illuminating some of our environment at
night. Buildings and monuments can be nicely enhanced by low-lumen,
fully-shielded lighting that is recessed and/or shines downward and not
outward or skyward. But lighting up buildings, monuments, flags,
and bridges just for the sake of lighting them up is more likely to
create ugly sights than aesthetically-pleasing sights unless careful
thought is employed in advance.
Most taxpayers do not realize that most streetlighting is
paid for from their taxes, that usually there is no legal requirement
mandating specific streetlights, that most outdoor lighting is highly
inefficient (much of it even dangerous), and that towns and cities pay
large monthly and annual bills to keep streets lit at night. My current
home town in Massachusetts has a population of around 27,000 but an
annual streetlighting bill in excess of $500,000 for electricity alone!
Single cities like Boston spend tens of millions of dollars every year on
electricity alone to light their streetlights, and I suspect that Providence
spends many millions each year for the same purpose. An increase to lighting
public buildings, monuments, and bridges is likely to incur large continuing
annual costs in electricity to keep the lighting glaring. And promoting
more energy usage and more night-time glare with the reward of tax
incentives for businesses does not appear to be sound policy.
I suggest that the City of Providence sit back and think for a while
longer about its outdoor night lighting. It might be better to do something
completely different, like implement an extensive outdoor-lighting ordinance
that mandates: that all outdoor lighting above a certain lumen threshold
(a minimum of 1000-2000 lumens is often used in such ordinances in other
cities and towns) be fully shielded; that lower-lumen light bulbs be used
to make light less glary; that all sign lighting be recessed, shielded, and
mounting at the top, pointing only downward and only on the sign; that
closed businesses turn off all signage and parking-lot lighting after a
certain hour (like midnight); that floodlights be banned unless they are
fully shielded so that their light is not emitted above the horizontal; and
that non-security lights around other public edifices be turned off after a
certain hour.
With the new energy-efficient sodium, metal-halide, and fluorescent lamps
now available, one can generally get the same amount of light on the ground
simply by shielding a lamp that uses half (or even a third) of the electricity
of older or existing unshielded lamps; these new lamps put out several times
more light (lumens) per watt than did older incandescent and mercury-vapor
lamps, but power-utility companies are loathe to tell the taxpayer that
they are so efficient, and they often replace 200-watt mercury-vapor lamps
with 200-watt metal-halide or HPS lamps, resulting in 2 to 8 times more
light on the ground! A 35-watt HPS or metal-halide lamp is quite bright
and is generally sufficient light for most streetlight applications.
A good general rule is that if one can see an outdoor
light bulb from 50-100 yards away, it is a bad light. Outdoor lights simply
are not effective when one gets a certain distance away, so an unshielded
light bulb above 1000 lumens becomes nothing but a glary eyesore when you
have moved a few tens of feet away from it (where its light is no longer
strong enough to be useful).
Just putting up a lot of glary, bright lights is more likely to backfire
on a city like Providence than to create huge benefits. Converting all the
existing streetlights to full-cutoff and encouraging businesses to change all
their lighting to full-cutoff will greatly enhance the aesthetic beauty of
the city. Give tax benefits to businesses that make their places look
attractive. It is possible to have an aethestically-pleasing night-time
environment in any city that includes the ability to see hundreds of stars
and even the Milky Way from that same city! Artificial lights alone don't
make the night-time environment appealing in any way at all --- any good
lighting engineer will note this fact. But once you see a nicely, not-overly
lit area in which the source of the lighting in invisible, you quickly
realize that a city or town (or business or neighborhood) can be made a much
nicer place to live in or to visit. Then you begin to wonder why everybody
doesn't put more thought into night-time lighting!
Respectfully yours,
Daniel W. E. Green [green@cfa.harvard.edu]
on behalf of the New England Light Pollution Advisory Group
(a volunteer group with members in all New England states)
http://www.cfa.harvard.edu/nelpag/nelpag.html
Also available is information from the International Dark-Sky Association.