Is light polluting the sky? Answers could keep you up at night
Light pollution, as defined by the International Dark Sky Association, is any adverse effect of artificial light, including sky glow, glare, light trespass, light clutter, decreased visibility at night and energy waste. Three economists from Missouri State University, Drs. Terrel Gallaway, David Mitchell and Reed Olsen, have published several articles on their recent studies of light pollution and the value of a dark sky, and they see economic effects in addition to the biologic and conservation issues.
Through surveying visitors to four national parks, the team assessed the value people place on a dark sky – one that is not showing sky glow. They tried to discern how much people would pay a utility company to have more efficient lighting placed in their communities and whether they would pay additional taxes to preserve the naturally dark sky. Mitchell explained some of the follow-up questions.
“Are they willing to pay to keep light pollution away from national parks but not their own home? For instance, people want to go to a place to be able to see tigers, bears and lions, but they don’t want tigers, bears and lions in their own backyard. It’s that idea,” he said.
Olsen said that 25 percent of power used in the U.S. is used for lighting and an estimated 30 percent of that is wasted as light pollution, equating to approximately $25-$30 billion per year.
The first studies of light pollution focus on the biologic aspects, Olsen noted. Most species on Earth depend on periods of light and darkness, and biologists are concerned about the lack of biodiversity when nocturnal animals are disoriented by light pollution.
“I think the most ubiquitous problems for humans, though, is a lack of sleep if it’s not dark,” said Olsen.
In June, CNN reported that toward the end of his life, Michael Jackson sustained more than 60 nights without reaching the REM (rapid eye movement) cycle – the deepest sleep cycle in which you experience dreams. Mitchell related Jackson’s scenario to their topic of light pollution and sky glow. If people sleep fewer hours overall, and therefore have less REM sleep, does that lead to more physical and mental health issues?
“It’s widely documented that when people don’t get good sleep at night, it interferes with their hormones. In women, this could mean higher incidences of breast cancer,” said Mitchell. Other chronic conditions that have been related to hormones or sleep include obesity, diabetes, migraines and hypertension.
At the national parks, for astronomers and for many Americans, the most visible problem associated with light pollution is the aesthetics.
“You don’t see a really dark sky in Springfield. The most recent example would have been during the ice storms of January 2007 when power was lost widely in the community,” Olsen said. “The situation was bad, but the skies were magnificent.”
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