Thanks to electric lights, outdoor lighting grew at a rate of 3% to 6% annually in the second half of the 20th century. While this has benefited human productivity and safety, it has come with a dark side: The night is no longer dark enough.
Half of Europe and a quarter of North America have experienced seriously modified light-dark cycles, the study authors wrote, calling it a “widespread ‘loss of the night.’ ”
This light pollution can have serious consequences for living things, which have evolved in accordance with a natural day-night cycle, where the only major sources of light at night would have been the moon or more intermittent sources such as volcanoes, lightning, wildfires or auroras.
Read more from LA Times