Light Pollution
For the first time in human history, more of our planet’s population lives in urban areas instead of rural locations. This change means that, from their own homes, most people can only view the night sky from a light polluted environment. In the United States, it is estimated that as much as two thirds of the population can no longer see the Milky Way. An unintended consequence of our modern world, light pollution is product of improperly installed and poorly aimed outdoor lighting. It can be seen in a number of ways
- Skyglow – the dome of light present over many cities and towns. the major cause of Skyglow is unshielded and excessive use of lighting.
- Glare – perhaps the most immediately hazardous form of light pollution. A public safety problem, glare can cause accidents by blinding the vision of pedestrians, bicyclists and motorists.
- Light Trespass – Light emission that is not contained within its property of origin. Common examples include residential security lights that shine into a neighbor’s yard or house and streetlights that not only illuminate the roadway, but also shine into residential property.
Here in New Mexico, ordinances have been enacted to help raise awareness about the problems of light pollution and curtail the wasteful practice of excessive outdoor lighting. The laws span the full spectrum of government ranging from the 10 year old state law, the New Mexico Night Sky Protection Act, right on through to the county and town level. In some cases, outreach and public education can be effective alternatives to an ordinance. Sensible lighting advocates strive to help people understand that while lighting is necessary for public safety and security, too much light is worse than no light at all.
Light pollution is insidious. Many people seem unaware there could be anything wrong with over-lighting homes and businesses until one evening, when they go out with their friends or children, and notice their view of the stars is reduced to little more than feeble points of light swamped by the artificial glow of perpetual twilight.
The good news is that unlike many other environmental problems caused by humans, light pollution can be reduced or eliminated by simple and low-cost countermeasures. Correcting bad lighting is as easy as installing a motion sensor, re-aiming lights to prevent emission above a horizontal plane or into a neighboring property, and turning off outdoor lights when they are no longer needed.
