framlingem

But ne'er to a seductive lay let faith be given;
Nor deem that "light that leads astray" is light from Heaven.
-Wordsworth

Urban sky glow is traditionally an astronomer’s problem. However, people in general are becoming more and more aware of its effects on health, the environment, finances, and the well-being of all. William Wordsworth was aware that not all light is “light from heaven”; indeed, light projected from the Earth can be severely detrimental, fully earning the term ‘light pollution’.

Light pollution can be briefly defined as the presence of light in a place where there should be no light. This is not entirely accurate, though, as some quantity of light is occasionally necessary; for example, public squares, parking lots, and roads must have some degree of illumination in order to be safe. Therefore the term ‘light pollution’ has also come to mean an excess of light in the areas where light is needed.

One of the most important contributors to light pollution is the widespread use of improper lighting – that is, lights which do not only focus the light downwards. This is especially apparent in such places as floodlit sports fields, buildings illuminated from ground level (for the purely cosmetic purpose of making them visible in a city’s skyline), and in such things as billboards, where only a tiny fraction of light falls on the advertisement. The rest dissipates upward and out, illuminating particles in the atmosphere to cause urban sky glow. In Spain, where more than thirty percent of lighting is wasted, a perfect example of such inefficiency can be found in Madrid, a city famous for its nightlife and public squares. These public squares are lit by fifty thousand traditional globe-shaped lamps, which, ironically, are only shaded on the bottom: the only area which should not be shaded. Madrid’s urban sky glow is visible at a distance of 200 kilometres from the city, and extends an astonishing eighteen-plus kilometers upwards. Barcelona is equally bad – an astronomer’s group has concluded that the two Spanish cities have upwards of five times the amount of light needed for nighttime comfort and safety. A second factor is the use of unneeded light – office buildings frequently leave lights blazing all night.

Light pollution is detrimental to wildlife, especially birds, who prefer to fly in the light. They will frequently exhaust themselves in an attempt to stay within the beam of a searchlight, falling to the ground and dying from the impact when they can no longer fly. Birds are also drawn to lights in high-rise buildings, causing them to fly into windows, which can also be fatal. More birds die every year of light-pollution-related causes than died as a result of the Exxon Valdez oil spill in the late eighties. Furthermore, added light creates a change in circadian rythms, as night has become twilight. This affects more than simple day/night perception. A creature’s preferred food may now not be awake at the same time as the predator, leading to drastic changes in feeding habits and hunting behaviour. Animals which cannot adapt starve. Similarly, confusion caused by light pollution can lead to changes in mating habits, resulting in drastic decreases in a species’ birthrate.

Light pollution not only prevents sleep, it also has an important effect on the quality of what sleep is achieved, due to the increasing impossibility of sleeping in darkness. In addition, night lighting has been positively correlated with an increase in myopia among humans. Further research is currently being undertaken to determine how extensive the environmental impact of light pollution is – however, it has been determined that excess light does have a detrimental effect on both animal and plant life.

If one examines the subject more closely, one can also determine that excess lighting also has indirect effects on the environment. To create light requires electricity, and nearly sixty percent of Spain’s electricity is produced by burning fossil fuels. Light pollution, then, is also a cause of rising carbon dioxide and sulphur levels in the atmosphere, increasing the acidity of the rain in Spain and accelerating the Greenhouse Effect.

What then, if anything, is being done to alleviate the problem of light pollution in Spain? The obvious solution would simply be to turn off all the lights, which, ideal as it may be, is unlikely to happen due to perceived human need for light at night. Another, much more practical solution would be to change the lights themselves, from the previously mentioned inefficient types to lighting which lights up only as much as is necessary – lights which are shaded on the top and sides. This is causing problems in Madrid, where the traditional globe street lamps are beloved by the public. "They light up treetops for a beautiful effect and create a sensation of warmth. Residents always want them in their neighborhoods," says Alfonso Marcos, an official with Madrid’s public lighting department. (Brown, 2000) However, Madrid has set a deadline of 2010 for replacing all fifty thousand of the lamps with more energy-efficient, less-wasteful versions. Barcelona, as well as more than twenty other sizeable Spanish communities, is following suit. In the town of Barlovento, such measures have already been taken, resulting in stunning reductions of light pollution (86%) and power consumption (65%), while only reducing the amount of useful light by 3.6%. Economically speaking, Greenpeace estimates that these projects, hardly cheap, will pay for themselves in energy savings within three years of implementation. The area of Spain which is at the forefront, however, is the Canary Islands, which have long had very strict reglementation of outdoor lighting, and have consequentially become a popular place for astronomers looking for observatories.

Light pollution is a problem in Spain, ecologically, economically and aesthetically speaking. The country is making an effort to correct this problem, but faces a population which is largely unaware that the problem even exists, and who like their bright lights. Knowledge that not all light is “light from Heaven”, though, is on the rise.

And yes, I know my conclusion sucks. I'm terrible at writing conclusions to pure research papers, as they are summaries and not really out to prove anything at all. I am proud that I got ol' Will Wordsworth in there, though.