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In page Light pollution:

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Global effects of light pollution are also made obvious. Research in the late 1990s showed that the entire area consisting of southern England, Netherlands, Belgium, West Germany, and northern France have a sky brightness of at least two to four times normal.[1] The only places in continental Europe where the sky can attain its natural darkness are in northern Scandinavia and in islands far from the continent.[citation needed] The growth of light pollution on the green band has been 11% from 2012–2013 to 2014–2020, and 24% on the blue band.[2]