Ten years ago, Smith College astronomy professor James Lowenthal would go to the roof of his building on campus, look up and see the Milky Way.
Today, that is no longer the case.
“Now you can just barely make out the faintest glimmer of the Milky Way,” he said. “I have to take my students to Cummington, or Chesterfield, or Worthington to see the Milky Way — to see anything approaching a dark sky.”
Sitting in Northampton’s Pulaski Park, Lowenthal said, “100 years ago we could be sitting here and see a spectacular starry sky — dark velvet black with bright Milky Way. Bit by bit, that’s been completely eroded until you can’t see hardly anything.”
The Northampton resident and others believe light pollution is to be blamed for this phenomenon, and the issue has implications that go far beyond seeing the stars better.
Lowenthal is president of the Massachusetts chapter of the International Dark-Sky Association, which calls light pollution “the inappropriate or excessive use of artificial light.” The nonprofit is focused on curbing light pollution worldwide.
Skies above 99 percent of people in the U.S. and Europe and 80 percent of the world’s population are light polluted, according to a 2016 study published in Science Advances. Eighty percent of North Americans can’t see the Milky Way, and the planet is only getting brighter. From 2012 to 2016, artificial lighting grew by 2.2 percent annually across the globe.
In Greenfield, efforts have been made to limit light pollution using Green Communities grant funding. The project, which was completed in 2016, involved installing 1,071 LED Cobra and 250 decorative lights throughout the town, according to Greenfield Director of Energy and Sustainability Carole Collins.
LED lights were installed in parking lots, schools and streets, which not only helped to reduce the town’s electric bill by 80 percent, but also helped reduce light pollution.
“That’s because we directed light only to go to the center of the road and sidewalks using the patterns for optimum safety,” Collins explained.
She added that the LED lights allow for the human eye to adjust to light easier, as the light emitted is more similar to moonlight.
The International Dark-Sky Association’s Massachusetts chapter supports a bill that would address the issue statewide by setting limits to publicly-funded outdoor lighting projects, and Lowenthal and others have been pushing for changes on the local level.
Beyond diminishing the visibility of celestial bodies for stargazers and astronomers, light pollution has a variety of other impacts.
Northampton resident Jenny Fleming-Ives has been working as a clinician in reproductive health for 30 years and worries about the health impacts of light pollution.
For example, in 2017, Harvard researchers found an association between outdoor light at night and breast cancer, possibly because the light can decrease melatonin levels. They published their findings in Environmental Health Perspectives, a monthly journal of environmental health research and news published with support from the National Institute of Environmental Health Sciences.
Fleming-Ives thinks many people don’t realize light pollution is an issue.
“A lot of people maybe haven’t thought about it that much,” she said.
She often tells people the lights on Bridge Street in Northampton are too bright and cause glare, and after a person drives there at night, they come back and say: “Oh yeah, I saw what you mean.”
Sleep can be affected by light pollution, too. One analysis found that people in light polluted areas take higher doses of sleep medication and for longer than those in less bright areas.
The American Medical Association recommends outdoor street lighting to be 3000 Kelvin — a measure of the lights hue — or less, and that they are shielded to prevent glare. The AMA estimates white LED streetlights have five times more of an effect on circadian rhythm, the body’s natural 24-hour clock, than traditional ones.
In Greenfield, street and parking lot lights are in the neutral to warm range of 3000 Kelvin, Collins said. All the lights are also directed (same as shielded), so that no light overspills or produces upward light pollution like traditional street lighting, she explained.
Statewide, legislation that aims to lessen light pollution has been filed and is cosigned by Rep. Lindsay Sabadosa, D-Northampton, Sen. Jo Comerford, D-Northampton, and Sen. Adam Hinds, D-Pittsfield.
The act would require improving outdoor lighting and increasing dark-sky visibility starting next summer. It calls for any outdoor lighting paid for by state or municipal funds be under specific limits for brightness and blueness. It would also require that new roadway and parking lot lights are shielded.
Lowenthal is pushing for it to pass.
“As an astronomer, I’m acutely aware of it,” he said of light pollution. “But much bigger than that, everybody in the world is affected by it.”