A Plea for the Night

By Dr. Klaus L.E. Kaiser —— Bio and Archives December 3, 2017

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Everyone cherishes the night. For most of us it's a time for contemplation, rest and recuperation from the day's hectic activities. For others, a "day of work" starts at nightfall. Despite the official calendar claiming that we are close to the longest night of the year (in the northern hemisphere), some facts appear to contradict that. For example, "light pollution" is steadily on the increase. It's being claimed (translated from German) that "99% of Europeans live under a light-polluted sky and 60% cannot discern the Milky Way." That's not only a problem for astronomers (hobbyists and professionals alike) but for everyone living in modern cities. Nights have become nearly as bright as some days with all the street lighting, for a long time already.

Artificial light, and the subsequent loss of night-time darkness, is "a very new stressor" that many organisms have not had time to adapt to, according to Franz Hölker, a scientist at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Germany. One may wonder why? Some history may be relevant.

Street Lighting

The whole idea of night-time city street lighting came up in 1417, according to some sources, when illumination was ordered in London by Sir Henry Barton, Mayor of London, presumably to improve public safety. The lights then were using piped coal gas as fuel. However, all that lighting did not prevent the murders by the infamous "Jack-the-Ripper" which are yet to be solved. Whether the historic account is true or not, since that time, night-time street lighting has become de rigueur around the world. How else could one partake of "night life," and feel safe? Of course, these days, most cities' streets are illuminated by electric lighting, some even day and night (probably due to faulty light sensors or other technical problems). In short, simply by decree, the formerly (true and dark) night times have been banned out of existence, especially in cities.

Is that still warranted?

With (infrared-enabled) street-corner cameras proliferating everywhere, 24/7-recording of any movement there, every vehicle on the road having its own lighting system, both to be seen and seeing ahead, small and inexpensive hand-held flashlights available for pedestrians (thanks to the new LED technology), it may be a legitimate question to ask: Is the bright night-time city street lighting still warranted? In medieval times, artificial light was primarily based on candle, oil, kerosene, or gas type lamps. It also was rare, expensive, and did not provide much illumination at all. The former unit of light output, CANDLE(s), shows that too. These days, light output is measured in LUMEN(s). This is something you should look at too when comparing different light sources in a store, not only their wattage, expected lifetime and cost. Well, times have changed. Especially with the new LED (Light Emitting Diode) type "bulbs", lighting has become much cheaper and more powerful. Compared to the incandescent light bulbs with tungsten filaments that were the norm until quite recently, LEDs provide five to ten times the light output for a given energy consumption. That is an enormous leap in the light/energy ratio!

LEDs are "In"

Even without that modern LED technology, street lighting and well illuminated offices and homes have become common place in recent decades. In fact, many high-rise office buildings have been lit 24/7, even before LEDs came about. Offices and stores are typically using fluorescent tube lighting that is also providing more light per energy unit than incandescent lights, but less than the LEDs. You may wonder how all the now nearly free light has affected (electric) energy consumption and lighting in general. The fallout from the modern fluorescent and more so the LED type light sources is not what was expected. The electricity consumption has not dropped because more people became more complacent and stopped turning off the light(s) altogether. As a result the level of night-time illumination in settled areas has increased even more than may have been the case with the older incandescent systems, both indoor and outdoor. In short, the nights (nearly everywhere) have become even brighter.

Night-time Illumination

The night-time illumination of most cities is steadily increasing. Not just because of expanding populations, but also due to the better light sources, such as LEDs, and more night-time "activity." Of course, there is a question as to which came first, the light or the activity. Apart from such considerations, most city politicians, engineers, and bureaucrats think more light is better. Even in the comparatively quiet residential area that I live in, the former street lights have been replaced with more energy-saving but perhaps more light-emitting devices. Our local wildlife, including whitetail deer, racoons, skunks, opossums, etc. don't seem to mind it. Actually, it appears to make it easier for them to find the right shrubs, flowers and other items they like to munch on. And as to petty crime, how can one know what to steal, if there were to be less lighting? Though there are songs and poems about America Never Sleeps, perhaps less light would rather be a deterrent for thieves and also energy saving for folks who suffer from "Sleeplessness in the city." Less illumination may also enable you to see and appreciate the colorful and fantastic Northern Lights (aurora borealis) that are often weaving their ever-changing patterns across the higher latitude night skies.