Learning Series: Managing Artificial Lightscapes

From our September 2025 YouTube archive

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Transcript

Traci: Welcome everyone to our learning series. We are honored to have a special guest with us today. Dr. Bryan Boulanger works at the intersection of education, engineering, and conservation, leading efforts that connect stakeholders with nature, protect ecological systems and cultural heritage, and explore innovative solutions for a more sustainable future.

He currently serves as the Engineering Centennial Alumni Endowed Chair for the Kokosene Department of Civil and Environmental Engineering at Ohio Northern University, and is a member of IUN’s World Commission on Protected Areas.

Bryan is a past recipient of the EPA’s Mission Award, a past U.S. National Academy of Science Research Council Associate, and a past DarkSky International Nocturnal Habitat Protection Awardee. Since 2015, Bryan has focused on developing tools and practices that decision-makers can use to reduce the impact of artificial lightscapes on surrounding nocturnal ecosystems, natural resources, and human experiences. His contributions have been used to improve natural nightscapes and manage landscapes and communities throughout the world. He has been instrumental in helping start DarkSky Ohio and remains our official lighting expert. Bryan, take it away.

Bryan: Thank you, Traci. That introduction made me feel a little bit older, but I appreciate it.

Today, I’m going to talk about managing artificial lightscapes. I’ll try to keep my comments mostly Ohio-focused, but the breadth of this work goes far beyond Ohio and far beyond the U.S. at this point.

Before I start, I want to offer some thank-yous, because the work I’ll talk about is really the culmination of many people’s efforts far beyond myself.

I want to start by thanking the members of DarkSky Ohio; Traci, for setting this up and for years of friendship; Terry Mann, one of the original founders; Bryan Summer, who has been involved since the beginning; and newer members like Erin, with whom we’ve had a growing relationship. Watching the group take off over the past year since I stepped mostly out of the leadership role has been really rewarding.

I’d also be remiss not to thank Ohio Northern University. We’re a small, undergraduate-focused engineering college in Northwest Ohio, located in Ada. Feel free to stop by anytime. Within our civil engineering program, we have about 150 future civil engineers in the pipeline, surrounded by supportive colleagues.

Thanks also to the National Park Service, particularly the Natural Sounds and Night Skies Division, with whom I’ve had a long-term relationship. John Barentine, a name many of you may recognize, was previously with IDA, now DarkSky International, along with staff members including Ruskin, Betty M, and others who have been long-term friends and colleagues.

And finally, my family. As I’ve traveled around the globe, I’ve usually had a family member with me. Five of my kids have served as field techs, and my wife has joined me in some wonderful places.

Bryan’s Motivation

Bryan: The motivation for this work came in 2007. I was out in the Guadalupe Mountains observing a night sky I hadn’t seen since childhood, when we traveled out west. Camping there one night in October, I realized two things: first, it’s unfortunate that I can’t see this where I live because of the civil engineering infrastructure we’ve built; and second, as a faculty member in engineering, maybe there’s something I can do about that for the next generation.

The image I like to use shows what a night sky looks like under truly pristine conditions, not as artistic as some photographs you’ve seen, but a real visual reminder of what is possible. This is what the night sky looked like all across our country just 100 years ago.

Many of you have probably seen the modeling work by Cinzano, Falchi, et al., which shows changes in light visible from above over time. In the 1950s, when my parents were born, people had a very different night sky. My grandparents and great-grandparents, even here in Ohio or in New England where I grew up, would have seen skies that look like the Guadalupes today. Because of development, we are rapidly moving away from pre-1950s conditions. And we are growing light spread at approximately 1–3% per year globally.

Why Should We Care?

Bryan: When I first got involved, my motivation was personal: I love spending time outside. For our astronomy colleagues who led the movement starting in the 1980s, the concern was that their ability to conduct ground-based visual and scientific observations was disappearing. Beautiful observatories were built that could no longer fully fulfill their mission, and they began pushing back against the status quo of development.

But there are many other reasons why a naturally dark environment matters to us and to the ecosystem. My own driver was the wilderness landscape. I’ve been fortunate to spend time in places like Yellowstone, where connecting with the night sky as a young person made a lasting impression.

The National Park Service, with their motto “Half the park is after dark,” cares deeply about the visitor experience. Federal land managers are also interested in energy usage; the federal government owns a large number of buildings and wants to reduce its footprint. In Ohio, for example, rest stops along highways are being redesigned with energy efficiency in mind, and lighting is a key part of that.

Whatever your driver is, thank you for being an advocate, for getting involved, and for continuing to learn.

Why Lighting Design Matters

Bryan: As an engineer, once I put two and two together, I became genuinely annoyed by poor lighting design. So much of what’s out there is simply bad design.

DarkSky International has great graphics to illustrate this. On one end, you have the acorn fixture, ubiquitous in Ohio and elsewhere. Some might say it has historical charm. But the fact is, any time you’re lighting upward instead of downward for task-oriented purposes, you’re wasting energy, causing glare, and negatively impacting surrounding ecological services.

Through better design, we can have lighting that performs all the same tasks far more effectively from unacceptable, to bad, to better, to best.

How DarkSky Rewards Good Lighting

Bryan: One of the most successful programs DarkSky International currently runs is the Dark Sky Places program. It has five categories, ranging from Community to Sanctuary, and brings people into naturally dark environments for stargazing, nocturnal habitat awareness, and discussions about proper lighting design.

DarkSky International recognizes that light pollution is a regional challenge throughout Ohio. What I can do on my own property matters, but the light in my night sky doesn’t only come from nearby sources. Because of this, they’ve built a scaffolded set of prerequisites that all categories must fulfill:

• A public commitment to dark sky quality.
• A lighting management plan: what will your lighting look like in the future?
• A lighting inventory, or knowing what you have and what condition it’s in.
• Education and outreach, or telling the story of why dark skies matter.
• Sharing your successes and helping tell that story broadly.

In Ohio, we have Observatory Park as a designated Dark Sky Park, along with Fry Family Park. These came in under older guidelines that didn’t require established night sky quality parameters. Today, qualifying as a Dark Sky Park in Ohio would be more challenging due to regional light pollution, but there are pathways through the Community and Urban Place designations.

The Bortle index governs which category a site qualifies for. Urban places have more impacted skies but still serve an important role, especially for children growing up in cities who may never otherwise understand what a night sky looks like. Urban places can host full moon walks, aurora viewing events, and more. I actually prefer the term “natural night sky” over “dark sky” because sometimes, during an aurora or a full moon, the night sky is anything but dark, and that’s worth celebrating too.

Geographically, you can think of it this way: Urban Night Sky Places are in cities, Dark Sky Communities are in suburban or rural transition zones, Parks are in our darkest areas, and when communities work together around a park, they can form a Reserve. Sanctuaries are reserved for our darkest, largest places in the world.

Bryan’s Work

Bryan: Since 2015, I’ve worked with a wide range of partners, most prominently the National Park Service, to support decision-making around artificial lightscapes. I now have just over 22,000 square miles under conservation status through the Dark Sky Places program, roughly half the size of Ohio. My Dean wants me to get it up to a full Ohio’s worth before I’m done.

I’ve worked with 61 partners. Recently, I’ve been handing off my tools to others. DarkSky Oregon, for example, now has two trained people who have replicated everything I do, and that’s exactly the outcome I hope for. If anyone on this call is interested in using these tools to do more in Ohio or regionally, please send me an email and we can talk.

A key part of my work is measuring and characterizing night sky quality. Using a fisheye lens, I capture 360-degree full-sky images to document what natural darkness looks like. For comparison, Olympic National Park at a campground on the Pacific shows a brilliant Milky Way with very little light pollution, while my own property in Ada, Ohio shows significant sky glow from Findlay, Lima, and Beaver Dam. The difference is clear.

I also support satellite imaging work. In one recent example, changes in the night sky over Middlefield, Ohio were detected, a spike in sky brightness traced back to a new greenhouse operation. Greenhouses are a frequent subject of inquiry. While they bring jobs to rural areas, from a design standpoint we can do much better at limiting their impact on the night sky.

Much of my work involves helping federal land managers understand their existing lighting. This includes:

• Baseline characterization, or understanding what lighting exists.
• Analysis and prioritization, or given a fixed budget, what do you change first?
• Project scoping and cost estimates (costs have ranged from a few hundred dollars for small parks to several million for larger communities).
• Fixture design and specification. Today there are many commercially available amber LED, fully shielded fixtures for egress, pathways, and other uses.

The tool I use for field data collection is ESRI’s Field Maps, a handheld GIS application that lets me log fixture type, lamp type, color temperature, shielding status, and more as I walk a site. All of this feeds into DarkSky International’s application process and into the lighting design process.

For example, at Hot Springs National Park, a fascinating park about historic health and rejuvenation, not geothermal springs, I inventoried all fixtures in the park last spring. The park owns the historic bathhouse fixtures along Bathhouse Row, and the surrounding town replicated the same style throughout. With a digital inventory in place, I can provide remote support for the park’s ongoing lighting transition. These projects often span years; my relationship with Yellowstone has now lasted nearly a decade from planning through execution.

What Does Good Lighting Look Like?

Bryan: The industry is moving toward more night-sky-friendly fixtures, which means light pollution should gradually reduce over time. Here’s what to aim for:

• Fully shielded, fully cutoff fixtures that direct all light downward, whether recessed building lights or pathway fixtures
• Color temperature of 3,000 Kelvin or less. DarkSky International recommends this threshold, and most partners I work with now aim for 2,700K or even 2,200K amber. These warmer tones replicate the feel of the original incandescent bulb while using modern, efficient technology.
• Dimming and controls. Modern fixtures can be controlled remotely or by phone. Curfews are increasingly common. Dimming to 25% after 11 p.m. still provides adequate light while dramatically reducing impact. If needed for any reason, full output can be restored instantly.

When I replaced an acorn fixture at Yellowstone with a night-sky-friendly Phillips fixture, the immediate result, even in a naturally dark environment, was a very bright fixture. That’s when dimming becomes essential: directing the light downward is step one; getting the right intensity on the ground is step two.

Q&A’s

Traci: Bryan also helped us get a light ordinance passed in Clark County. His imagery showing how dramatically the night sky has changed over the last 10 years was really compelling locally. For those who work in the park system…where would someone begin if they want to change out their lighting?

Bryan: Education is the starting point. If there’s interest at a cluster of parks or at the ODNR level, I’d be happy to facilitate a workshop on how to walk up to a fixture and assess whether it’s compliant with best practices, whether those are DarkSky International guidelines or whatever standard your organization has adopted. DarkSky International also has excellent online resources, including guidance on how to talk to neighbors about their lighting. Sometimes an organization just needs one outside voice to come in and advocate, and momentum builds from there. I’m happy to serve in that role.

Traci: Can you say a few words about why this matters for wildlife, human health, and our cultural connection?

Bryan: I could give a two-hour presentation on this alone. The short version: nearly every study I’m aware of demonstrates some negative ecological impact from artificial light at night. All animals and plants have evolved within a natural cycle of light and dark. That cycle governs photosynthesis, circadian rhythms, nocturnal and crepuscular activity patterns, and navigation. Disrupting it with artificial light has real biological and physiological consequences for wildlife and for humans.

A practical example: if you’ve ever approached a lighted facility at a state park at night, you’ve seen the clusters of insects trapped around the light. Switch to amber LED bulbs outdoors and that problem largely disappears. Insects don’t respond to that wavelength the way they do to white or blue-white light. The relationships between lighting, pollinators, predators, and ecosystems are complex, but the impact is consistent across studies. The human health evidence is also growing, rooted in the fact that exposure to light during hours when we have not historically been exposed has consequences for circadian function.

Question From Chat: Can you provide cost estimates for dark sky lights with dimming and timers versus traditional acorn lighting?

Bryan: Today, dark sky-friendly fixtures and traditional acorn fixtures are essentially the same cost because they come from the same manufacturers. Sternberg is one example: on Ada’s Main Street, you can replace acorns with dark sky-friendly alternatives at the same price point. If you’re doing new installation, running conduit is the main added cost. There are also some dark sky-friendly solar lighting options that have worked well even in Ohio. In most replacement scenarios, making the better choice doesn’t cost any more.

Traci: So when we’re talking to parks and government leaders, we can tell them they can make a better choice for the same amount of money?

Bryan: Absolutely.

Traci: Can you briefly summarize the Dark Sky Places application process?

Bryan: You can find everything at darksky.org or by searching “Dark Sky Places application process.” The key requirements are:

1. Public commitment. Your organization must formally commit to dark sky quality.
2. Lighting management plan. What will your lighting look like going forward, including how you’ll handle any historical structures?
3. Lighting inventory. Document all fixtures and their condition, with a plan to bring them into compliance. The plan spans 10 years: you must reach 66% compliance to receive designation, 90% within 5 years, and 100% within 10 years. This long timeline reflects the reality of capital budgets and the fact that most LEDs installed today will need replacement within about seven years anyway.
4. Science, education, and outreach. Explaining why dark skies matter. Caesar Creek’s new nature center, for example, will feature a dedicated night sky exhibit.
5. Signage. Telling your story on-site

The most common stumbling block is the lighting inventory, and that’s exactly where I can help here in Ohio.

Question From the Chat: How can someone at home access satellite imaging of their location over time, say from 1985 to present?

Bryan: There’s a researcher based in Slovenia named Jurij Stare who runs a resource I believe is at lightpollutioninfo.map. Someone can look that up and post it in the chat. It’s ad-supported, but it’s an excellent tool. You can look at light trends over time, browse sky quality measurements from observatories around the world, and the data goes back at least 10 years. There’s also a secondary resource within the site that draws on original satellite imagery going back further. I’ll post the link afterward if it’s not already in the chat.

Erin: One example of progress at Caesar Creek: our beach shelter house recently had new lighting installed by contractors, well-intentioned, but not dark sky-compliant. Our park manager was immediately receptive when we raised the issue, and she agreed to simply turn the lights off until we can replace them properly, turning them on only when genuinely needed.

We saw the impact of that decision at our meteor shower campout. Attendees turned off their tent lights and lanterns and were able to experience the full moon together. It was almost magical to share that with such a large group. The response on social media showed how receptive the community is.

Our new nature center will feature an entire room devoted to the night sky, exploring why it matters to wildlife, to human health, and to our cultural heritage, especially given our proximity to Fort Ancient, which has a Northern Maximum Moonrise event coming up on October 11th. Fort Ancient is one of the few places in the world that tracks the full lunar cycle. Events and outreach like this get people outside, connect them to natural darkness, and build community support.

Traci: Bryan has offered both to help with lighting assessments and to train others who want to learn what he does. If you’re interested in volunteering to help carry this work forward in Ohio, please reach out. It’s a labor of love and a volunteer effort, but you get to explore the great state of Ohio and its parks.

A huge thank you to Bryan. He came down to Caesar Creek, got the ball rolling, and the results speak for themselves. He’s making a difference all over the world, and that’s something for all of us to strive for here in Ohio.