Light Pollution: Environmental Impact
Light pollution has an enormous impact on the health of human communities. But, putting ourselves aside, what is the impact of our lighting schemes on the rest of the world? It doesn't take a biologist to understand that unnatural light might have some serious consequences on life adapted to natural darkness. Drivers who may have ever come across a deer in the road are most likely aware that animals don't react well to bright light at night. Aside from common jokes about deer in headlights, recent research has revealed that light pollution in the form of sky glow is having some serious effects on the natural world. The prevalence of excess light is varied throughout the world. Thankfully, urbanization has yet to encroach on the most biodiverse regions of the Earth, the largely untouched equatorial rain forests of the Amazon on Congo. These important natural habitats are still among the most isolated areas on Earth and should remain so for the foreseeable future. At the far northern reaches of the Earth, the halo of forestation that surrounds the Arctic, the arboreal forests, are also largely sparred from the impact of light pollution. The areas in between aren't so lucky. The most heavily developed regions of the Earth lie in the temperate climates of the northern hemisphere. The three contents of Asia, Europe and North America are home to five sixths of the planet's people. At the same time, this encompasses more almost two thirds of the planet's habitable land area. Essentially, this means that an enormous portion of the planet's ecosystems are now victims of humanity's light pollution issues. Animals which depend upon the veil of darkness for security or advantage are the most heavily effected. The animal kingdom is much better adapted to living in low light levels, and the slightest increase in the brightness of the night sky can have dramatic effects. Among these effects are radical changes in the behavior and balance of certain ecosystems. Sky glow alters animals' perception of the sky and can disrupt natural migration patters. Evolution has accurately adjusted the natural navigation systems of a large number of animals to make use of certain patterns in the night sky. Urbanized areas block out a significant portion visible objects in the sky, leaving only the brightest stars. Because most migration patterns pass through one or more of ever increasing urban areas, some animals simply loose their way. In recent decades the migratory patterns of birds have become noticeably altered due to light pollution. Bird species have begun to appear in areas where they were previously unknown to visit. For some species this means migration to places where their common food source is scarce or nonexistent. Sea turtles are also victims to changes in light patterns, often crawling out of the sea in the wrong place to their eggs. When the eggs hatch the altered shadows of features on beaches, such as sand dunes, will cause the young turtles to scramble in the wrong direction, either parallel to or away from the sea. Certain species of plants are suffering as well. This is not because of the direct effect of light on the plant itself, but of light on insect species which commonly pollinate the plant. Its common knowledge that insects are attracted to light sources, hence bugs tend to gather around man made structures rather than perform their natural pollination duties. For homeowners that live at the edge of urban areas, there are several light solutions that can help reduce the attraction of insects and some animals. Aside from turning off any outside lights at night homeowners can choose Homeowners living in cities can take a similar approaches to help to reduce light pollution the animals that pass over their homes. Dark sky lighting is specifically designed to reduce excess light and is a good place to start. California has a standard known as Title 24 which is employed by certain manufactures. Also, Energy Star compliant lights are excellent choices since their intention is to reduce energy excess.