the size of the effect depends on the color

With Light pollution has become a growing problem, and skylines continue to grow, the night sky becomes dimmer and dimmer. However, researchers estimate that that night time sky could become bluer thanks to LED lighting.

Christopher Kyba, physicist at the Freie Universität and lead author of the study, said in a press release that , “The current worldwide trend of replacing gas discharge lamps with solid state lighting, such as LEDs, will affect the radiance and spectrum of urban skyglow.”

Franz Hölker, ecologist at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries and study author, said for nearly all of evolutionary history, clouds have made the night sky darker, just like what we witness during the day time.

However, in areas with artificial light, the effect of clouds is now reversed, and the size of the effect depends on the color. The team found that in Berlin, the blue portion of skyglow is 7 times more radiant on cloudy nights than on clear nights, and 18 times more for the red part.