5 Ridiculously Easy Ways to Fix Light Pollution: Kelsey Johnson

Ever gaze up at the starry night sky? This stunning view is at risk of disappearing — unless we act now, says astrophysicist Kelsey Johnson. In this fascinating, unexpectedly funny TED talk, she explains how light pollution affects almost every species on earth (including us) and shares five “stupidly simple” things you can do to help solve the problem.