What is Light Pollution?

Have you ever been to a place so far from civilization that you can witness the beauty of the true starry night sky? Or are you trapped in a city where bright, artificial lights run 24 hours a day, replacing the real night with an orange haze? This is light pollution, when the artificial light put out by our cities becomes excessive to the point of being intrusive on the environment.

Light pollution, like many other forms of pollution, is very recent in the wide expanse of Earth's history. It is a strictly man made pollutant, only emerging when we began to industrialize and use light bulbs. Two hundred years ago, some of the most populated cities of the world wouldn't have had a glow at all, because it was well before the advent of the light bulb. Now look at it in the above photo. All of Europe and most of the United States is covered in so much artificial light that it can be seen from space. Everyone knows there's a lot of artificial light all over the world. What we don't realize is the effect that all of this light can have on the environment.

Ecosystems around and within our brightly lit cities can be negatively affected by the overabundance of unnatural light. There are a multitude of nocturnal species for which light serves as a powerful biological factor. Many animals' behavior can be altered by artificial light, such as their feeding, breeding, and migration patterns. Artificial light can also interfere with the natural photosynthesis of plants by simulating sunlight at unusual hours, and competing with it during the day. Each of these changes caused by light pollution have already been altering the ecosystems near our cities, and the effects will only spread from there.

Another component of light pollution is the incredible amount of energy we use to power millions of artificial lights. Is it really necessary for an entire city to be brightly lit all through the night? We could turn off some lights and save much of the previously wasted energy. If we reduce the number of lights turned on at night to save energy, and in the process reduce the light pollution that can harm ecosystems. Saving, rather than killing, two birds with one stone, if you will.

Light pollution as a whole is a known idea, but it is often misunderstood. It does more than just block out the stars. It can greatly harm the environment by interfering with ecosystems and wasting energy needlessly. Light pollution is an important problem that needs to be dealt with, but with small things such as reducing our use of artificial light, we can accomplish our goal of reducing light pollution as a whole.

For more information on what light pollution is, see:
National Geographic on Light Pollution
Light Pollution Overview-Wikipedia