Light pollution has become a pervasive and ugly consequence of our 24/7 society, and it has grown at the alarming rate of 10% per year over the past decade. Few of us can enjoy a star-spangled night sky any longer, thanks to the glowing pall caused by all the lights that line roadways, parking lots, and backyards. More ominously, a growing body of research finds that excessive light at night disrupts nocturnal ecosystems, sometimes dramatically. It can also inhibit the production of melatonin, a compound produced as we sleep—and only in darkness— that seems to play multiple roles in maintaining general human health.
The situation has not been helped by the widespread rollout of light-emitting diodes, or LEDs. Fortunately, the spread of light pollution can be halted and even reversed. Join Sky and Telescope magazine’s Kelly Beatty as he discusses how we can safely light up our homes, businesses, and communities without wasting energy, disturbing the neighbors, or creating an unhealthy environment for humans and wildlife.