Dense concentrations if brightly-lit buildings are often a sign of rapid economic development. Estimates show that out of 3 billions dollars spent on skylighting each year, one-third is wasted. Artificial lighting can have negative impacts on humans, sea turtles, warblers and deciduous tree species.
Environmental light pollution is the term that describes the disruption to the natural light cycles within an ecosystem as a result of artificial lighting. ELP can cause shiftwork-related illnesses, mass deaths of species, and ecosystem failure. Researchers have observed ELPs effect on sea turtles hatchlings who mimic the reflection of starlight on dark water bodies. It has also been well documented that field crickets, mockingbirds from northern latitudes, and especially migratory species are affected by this navigation failure. These birds become so enamored with high-intensity light sources, they tire themselves out as a result of circling them. Attraction towards artificial light can also increase vulnerability to predators. Certain species have been shown to be able to adapt artificial light to their environment and use its increased visibility to hunt prey. These seemingly positive effects may have a negative impact on the ecosystem as a whole. Ecological cascades are caused by over-predation. Predation or out-competition may cause extinction of certain key species.
The loss of biodiversity not only affects conservation, but can also lead to the extinction of other species which depend on those key species. ELP affects more than just animals. The deciduous forest is home to Canada’s most endemic trees. Scientists discovered that deciduous trees in the vicinity of ELP shed their leaves earlier than other trees. The trees cannot tolerate the temperature drop, resulting in a poor transition into winter. ELP is also harmful to humans. A study found that nurses who had worked night shifts for more than 15 years were at a higher risk of colorectal and breast cancer. New Mexico instituted a Night Sky Protection act, and light pollution has been legalized in Arizona and Czech Republic. In Ontario, the number of bird deaths dropped from 2278 per year to a mere few after the lighting at the power plant was changed.
Local governance has created legislation, however, there is often little incentive for municipalities to enforce lighting regulations. Scientists call this a race towards the bottom. Experts call on the public and businesses to take a more socially conscious approach, to incorporate light pollution into education curriculums and to make the federal government aware of the health and environmental risks associated with ELP.
