John Barentine, a physical scientist and program manager for the IDA, said the concept of light pollution can be fairly subjective. For some people, skyglow or the brightening of the night sky that makes it difficult to see the stars, may be an acceptable consequence to being able to see at night, he said. For others, a single neighbor’s lights glowing from their property into the neighbor’s windows at night, called light trespass, is a major problem, Barentine said.
The IDA receives many requests opposing holiday lighting because it contributes to light pollution, but Barentine said the organization must take a pragmatic approach to solving the problem. “We are not trying to turn the world’s lights off,” he said. “We know that is not a practical solution to the problem.”