Buns, Downtown Delaware, OH (source)
Since 2010, the scientific literature has exploded with research examining light’s effects on individual species, from birds to fish to trees to humans. The news, in general, isn’t good. Artificial light changes animal migration and reproduction, tree leaf growth, bird nesting and fledging, pollination, human sleep, and much more. It even affects the spread of diseases. In July, researchers reported that West Nile–virus–infected house sparrows that live in light- polluted conditions are infectious for two days longer than those that live in darkness are, increasing the risk of a West Nile outbreak by 41 percent.
More: The Dark Side of Light