While this has benefited human productivity and safety, it has come with a dark side: The night is no longer dark enough. But even in those brightly lit countries that appeared stable, light levels are probably still on the rise, the scientists said. That’s because many well-lit cities have been replacing yellow-orange sodium lights with energy-saving LED lights. “What happens instead is that people put more lights up.”The blue light in those LEDs also are particularly disruptive for many nocturnal animals, researchers said. There also are ways to position and manage existing light sources — say, the lamps in a parking lot — so that they are not as bright but still are effective.

Source: Los Angeles Times November 22, 2017 21:45 UTC