Who’s afraid of the dark? Light pollution discussed at festival

The annual Borrego Springs Film Festival marks its 10th anniversary this week with film screenings, award ceremonies, networking events, workshops and panel discussions from Thursday through Jan. 16. This year, one of those community panel discussions is centered around the issues raised in the documentary “Defending the Dark” and the work to reduce light pollution and preserve dark sky parks and communities, including Borrego Springs, Anza-borrego State Park and Julian.

The film, by Tara Zabriskie, documents the dark sky advocacy work being done in Maine, and how that work can extend to other areas to reduce the harm of light pollution to people, plants and animals with its effects on sleep, bird migration, pollination and other issues. The panel discussion is from 3 to 5 p.m. Friday at the Borrego Springs Public Library and features Zabriskie, astronomer and scholar Douglas Arion, and screenwriter Matthew Carlson, whose astronomy film “This Wild Abyss” is being screened at 1 p.m. Friday at the Borrego Springs Performing Arts Center.

Arion is executive director of Mountains of Stars, a public science education organization, and professor emeritus of physics and astronomy at Carthage College in Wisconsin. He’s featured in “Defending the Dark” and took some time to talk about the film, his advocacy work, and ways that people can take individual steps to reduce light pollution in their communities. (This interview has been edited for length and clarity. For a longer version of this conversation, go to sandiegouniontribune.com/sdut-lisa-deaderickstaff.html.)

Q:

You’re part of the “Defending the Dark” community panel discussion on Friday about dark skies and light pollution. First can you talk about what light pollution is and why it’s an issue people should be paying attention to?

A:

Light is useful and having light in the right places at the right time is a good thing, but we very consistently overlight things and that excess light actually creates a whole suite of problems. Firstly, a lot of that light goes up, meaning it’s not illuminating anything useful. If the power went out at your home and you grabbed a f lashlight, you wouldn’t point it up at the ceiling, you’d point it down on the ground. So, light going up doesn’t do anybody any good.

To make that light, you have to make electricity, so you have all of the pollution of that. [According to the Environmental Protection Agency, the national average carbon dioxide output rate for electricity generated in 2019 was more than 884 pounds of CO2 per megawatt hour, translating to just over 953 pounds of CO2 per megawatt hour for delivered electricity. And, in 2020, the U.S. spent $1 trillion on energy, or $3,039 per person when spread over the population, based on information from the U.S. Energy Information Administration.]

Two, there are links between excess lighting and a variety of hormonally-based cancers and diseases, so if you live in a light polluted area and you have street lights coming into your home, the incidence of breast and prostate cancer is higher [according to research published in the journal Environmental Health Perspectives in 2018]. Excess light creates glare, so you want light on your target. You don’t want light coming into your eyes. For example, driving on highways in the rain with overhead lights actually makes it harder to see than easier to see, so light coming into your eyes has been a problem in terms of other natural effects. It affects birds each year that are trying to migrate, it reduces pollination by insects and birds and that affects your plants, which includes your food. So, it has huge effects on them, as well. It’s a wide range of effects on the environment, and it’s generally not a good thing, so those are the effects of excess light and the blue lighting that does most of the damage.

Q:

What’s involved in the work to preserve the darkness of the night skies? And why does that lack of human-made light matter?

A:

You can have lighting, but that lighting should meet some very basic characteristics, and the Illuminating Engineering Society and the International Dark Sky Association came up with a simple set of guidelines. One, light should be useful. There should be a reason to have it. You don’t just light something for no apparent reason.

It should be controlled; it should be on only when you need it. So, it’s perfectly reasonable to have a light by your front door so that you can find the hole to put your key in, but it should be on when you do that; you don’t need it on the rest of the night.

It should be targeted, so it should only light what you need to light. If you have a pathway between buildings that people are going to be traversing, by all means, have light on it; but you don’t spread light outside of that pathway. A lot of things are grossly overlit, like gas stations.

Q:

How do you respond to people who may argue that more lighting can increase safety and deter crime? If the position is to reduce that light, what would be the alternative for safety?

A:

It’s not that you don’t have to have lights, it’s that you have to have the right lights in the right places. By all means, if you have a facility, have lights with motion detectors all around your building. If someone comes up to a light, it comes on and then it goes off. Lighting up the entire five-acre parking lot 24/7 doesn’t make sense if the store isn’t open and nobody’s going to be there. Why not have building lights by entrances and by windows that are motion detected, so if somebody does try to come in, the light comes on and there’s a camera there to see? That’s an important aspect of the whole light pollution movement; it’s not having no light, but it’s using light better that will actually make a place safer.

lisa.deaderick@sduniontribune.com