Join the Conversation About Light Pollution in Salt Lake City

Cities with severe light pollution develop a aura over the urban area, which prevents residents from seeing stars.

By Bettymaya Foott, senior in Environmental & Sustainability Studies

“Night is certainly more novel and less profane than day.” — Henry David Thoreau

The first light bulb was invented in 1879. Before then, nighttime light was provided by fires or candles. With the widespread adoption of electrical lighting in urban and rural homes this past century, humans are beginning to live in a world without darkness. The loss of the night sky for urbanites is tragic. The ability to view the night sky is becoming a limited resource now, one that city governments seems to regard with complacency.

It turns out that all this light produces many consequences—for our global ecosystems, migrating wildlife, and even human psychology and health. The broad term for this problem is light pollution. Light pollution is defined as any adverse effect of artificial light. There are different types of light pollution, including:

• Light trespass: Light that illuminates beyond the property boundary;
• Over-illumination: Too much light as a result of improper design;
• Light clutter: Excessive number of lights in a group; and
• Skyglow: The illuminated aura present over urban areas at night.

Light pollution map of the United States. Areas that are white represent levels 8 and 9 on the Bortle Dark-Sky Scale. Source: Big Sky Astro Club

Residents of Salt Lake Valley live with a high amount of light pollution. Parts of the valley rate a Class 8 on the Bortle Dark-Sky Scale, measured from one to nine. This puts us at a similar level to other cities, including Los Angeles and New York City.

I have firsthand experience with participating in creating solutions to light pollution on the University of Utah campus. I learned that to be dark sky compliant means that no light can be emitted from a light fixture above the 180-degree plane. Basically, all the light can only be directed down toward the ground where it is needed. I noticed that the lights in Fort Douglas near the residence halls were doing the opposite of that. The globes were emitting 360 degrees of light, shooting it up into resident rooms and into the eyes of nocturnally migrating birds.

This illustration shows the different types of exterior lighting and the effects on light pollution. Source: delmarfans.com

I applied for and received a Sustainable Campus Initiative Fund (SCIF) grant, which funded a total of five full cutoff fixtures to replace acorn-shaped, non-cutoff fixtures. The new cutoff fixtures also comply with historical standards for the Fort Douglas area.

Through a SCIF project, new cutoff lights that meet historical standards were piloted in the Fort Douglas residence hall area to cut down on light pollution.

Bill Leach, lighting specialist for Energy Management in Facilities Management and an advisor on my project, says that the University is working toward making campus exterior lighting “dark-sky compliant.”

“Because of the huge number of walkway and parking lots on campus, we have been upgrading as budgets allow. Much of the lower campus has been done, as well as a considerable portion of the Medical Campus,” he says. “Because the Fort Douglas campus had not been addressed, this SCIF project was particularly timely as we try to address the dark-sky compliant goal while keeping the historic flavor of the space.”

Leach says that the new campus standard fixture for both walkways and parking lots is dark-sky compliant. The U is also looking at updating campus standards to require dark-sky compliant lights on building exteriors and is moving toward all LED lights for exterior fixtures.

Creating solutions for light pollution addresses the initial issue, and it brings about many other benefits, including economic savings. There are monetary savings in both energy and maintenance costs with each new lighting fixture installed. A single fixture will save the University about $70 per year. If this was scaled up to the 316 fixtures in the Fort Douglas area, savings would range from $21,000-$23,000 annually. LED fixtures can potentially last up to 15 years, meaning the savings could be rather significant.

There needs to be political action taken to reduce light pollution. Here in Utah, Ogden Valley has a dark sky ordinance, and they are on their way to opening up a dark sky park called North Fork Park that is adjacent to the urban area. Generally, cities don’t have much time to devote to the problem of light pollution— if they are even aware of the issue at all—but North Folk Park gives me hope that dark skies and cities can co-exist.

To get involved, come to a free screening of “The City Dark,” which will be followed by a panel discussion, on March 26 from 7-9 p.m. in the Union Theatre. Bill Leach, lighting director for U of U Facilities Management, will join U Professor Stephen Goldsmith and Weber State Professor Jeremy Bryson on the panel.

For more information about dark sky efforts, visit www.darksky.org.