"Like in many other ways, as humanity, we have caused great, landscape-scale changes to the world, particularly in the last century or so," said John Barentine, program manager for the International Dark Sky Association, a Tucson, Ariz.-based nonprofit organization that works to increase education about the impact of light pollution and what can be done about it.
"One of the ways is, we've fundamentally altered the nighttime landscape through the use of artificial light. That has so many impacts, and it goes beyond just being able to see stars in the night sky."