Feb. 11 (UPI) -- Light pollution now affects much of the globe -- and most of the planet's most important wildlife areas, according to new research.
As the new research reveals, light can reach habitat far from human settlements. When it's reflected and refracted in the atmosphere, light beams can travel long distances. This type of light, called "skyglow," impacts some two-thirds of Earth's Key Biodiversity Areas, as defined by the International Union for the Conservation of Nature.
Species living in more than half of the planet's Key Biodiversity Areas are living beneath artificially brightened night skies.
Previous studies prove light pollution can alter the behavior of specific species and impact entire ecosystems.
"These results are troubling because we know many species can respond even to small changes in night-time light," Jo Garrett, postdoctoral researcher at the University of Exeter, said in a news release. "Night-time lighting is known to affect microbes, plants and many groups of animals such crustaceans, insects, fish, amphibians, reptiles, birds and mammals."
Light pollution can affect the timing of when plants put out leaves and open their flowers. Often, birds begin singing earlier in the day in places featuring artificial light. Light-induced changes in microbial behavior can alter the cycling of carbon and other organic compounds.
Scientists quantify light pollution by the amount of artificial light present, as well as by how far the artificial light extends above the horizon. Skies with light pollution extending across the entirety of the sky are said to be polluted to the "zenith."
According to the latest analysis, published this week in the journal Animal Conservation, more than 20 percent of of the Key Biodiversity Areas feature skies polluted to the zenith. More than half of the wildlife areas in the Middle East are polluted to the zenith. Europe and the Caribbean also feature night skies heavily polluted by artificial light.
As developing economies continue to grow across Asia, South America, the Middle East and Africa, home to large swaths of biodiverse habitat, light pollution levels are likely to increase.
"Skyglow could be reduced by limiting outdoor lighting to levels and places where it is needed, which would also result in considerable cost savings and lower energy use," said Exeter professor Kevin Gaston.