Light pollution, also known as photopollution or luminous pollution, is excessive or obtrusive artificial light.The International Dark-Sky Association (IDSA) defines light pollution as: Any adverse effect of artificial light including sky glow, glare, light trespass, light clutter, decreased visibility at night, and energy waste.
It overwhelms fainter objects, and in bad cases even the brightest stars, reducing the glory of the sky to a washed-out glow.
Light pollution wastes incredible sums of money nation wide. While the cost to the typical homeowner might be in the $150-250 range per year the cost to the nation is approaching $10 billion annually. This is an absurdly large amount of money to waste. Diseases could be studied, the hungry could be fed, our nations children could be better educated.
Believed to be increasing by six per cent a year globally, artificial lighting is already known to affect individual organisms, but this is the first time that its impact on whole communities has been investigated.
Light pollution offenses are wide and varied. They represent a major threat to astronomer’s ability to see any celestial bodies in our current visible skyline and are categorized by their known adverse effects on the health of animals, plants, humans and the environment.
U.S. roadways contribute a huge amount of waste light. All of that bad lighting could be redone by replacing the up-pointing 300W halogen bulbs with more efficient LED lights and by pointing the LEDs down, thus cost far less for the taxpayers with out causing a single change in the quality of information delivered to the traveler or to compromise their safety.
We can minimize our impact on light pollution by lighting more efficiently. When we choose efficient luminaires and lamps, fewer lamps may be required to meet the lighting objectives, resulting in less wasted light emitted into areas where the light is not needed.
Quality lighting is well shielded (so the light is used, not wasted), uses the right amount of light, includes time controls when possible and includes the use of low pressure sodium (LPS) as the light source when possible (LPS is the most cost effective light source, excellent where color rendering is not critical).
The night sky in the country looks remarkably different than the sky view near a city. More stars are visible and brighter, and in some remote areas, the Milky Way galaxy extends across the sky from east to west. In contrast, lights in the city illuminate night skies, hiding many of the stars. Outdoor lighting that interferes with the natural landscape is called light pollution.
The growth of light pollution has been rapid and widespread. The brightening of the night by outdoor lighting affects a wide range of natural resources as well as human quality of life, and is increasingly targeted by sustainable initiatives.
Sometimes whole flocks collide with over-lit structures. According to Mesure, over two consecutive nights in 1954, 50,000 birds died at Warner Robins Air Force Base, Georgia, when they followed lights straight into the ground. And in 1981, over 10,000 birds slammed into floodlit smokestacks at the Hydrox Generating Plant near Kingston, Ontario.
The annual eco-event kicked off for the first time in 2007 when more than 2.2 million residents of Sydney turned off their lights in a call to action conceived by the World Wildlife Fund and the Sydney Morning Herald.
The lights are beneficial to some species, but harmful to others, according to a new study that raises questions about human impact on wildlife.