Consider the environment when changing lighting in Kincardine’s downtown

To the Editor:

My wife and I are members of the Huron Fringe Field Naturalists. We are writing to express our concerns about the Town of Kincardine’s downtown revitalization project, specifically with respect to the “enhanced streetlights” described on the web page for the project.

Driven primarily by economics, many municipalities are undertaking projects to improve the energy efficiency of public lighting through upgrades to new LED-based systems. From an energy efficiency, and hence, climate crisis perspective, this is a good move. That said, these new systems will be with us for decades, so it is vital to choose the technology and its implementation wisely.

Our concerns are primarily environmental. Specifically, the deleterious impacts that unconstrained artificial night-time outdoor lighting has on ecosystems: the health of plant, insect, bird and mammalian populations and their inter-relationships, including on human health.

The impact that artificial outdoor night-time light has on nature has been well-studied and is ongoing. The science suggests that there are four aspects of artificial outdoor light that should be optimized, or constrained, in order to minimize its negative side effects. Below is a very brief discussion on these aspects. It provides just a hint of the unintended side effects of artificial light and, therefore, the need for Kincardine to consider its lighting choices carefully.

Brightnessⁱ and Extent of Lightingⁱⁱ

Artificial lights can upset the proper balance in the nocturnal predator-prey relationship. Altering the natural ratios and presence or absence of species can stress, alter and even break ecosystems. The wider impacts are complex and difficult or impossible to predict.

These effects are not just limited to terrestrial ecosystems but aquatic ones as well. Wave action is effective in scattering even low-angle light deep into the water column, creating an artificial twilight. This is especially relevant for a coastal community like Kincardine. We must do our best to minimize the upset that night-time lighting can cause by limiting where we illuminate and by how much.

Spectrumⁱⁱⁱ

The wave length of the sun’s light reaching the earth’s surface changes through the course of the day. Living things have evolved to take behavioural cues from these diurnal changes in spectrum. There are numerous ways in which spectrum affects biology. Here are a few examples:
 

• The introduction of artificial light, without regard to wave length, can upset the competitive balance of plants (as some are more resilient to unnatural conditions than others).
• Plants also use the naturally-changing spectrum as a seasonal cue to schedule events, such as flowering, fruiting and seed production. The use of incorrect wave lengths in artificial light during twilight can alter these schedules. Insect and animal species have evolved to be in sync with these events. An upset in plant timing can ripple through an entire ecosystem.
• The penetration of light into the water column varies with wave length. Different species of fish have variable sensitivity to wave length. Diverging from the natural spectrum can change the completive balance between fish species.
• Insects’ behaviour is highly tuned to spectrum. Their response to an unnatural perpetual twilight spectrum can make them more or less susceptible to predation, with a corresponding ripple effect on predator species, such as bats, mammals and birds.
• The circadian rhythm schedules in animal (including human) biochemistry over a 24-hour period are synchronized to its daily schedule of activities. These activity cycles are driven by the changes in diurnal spectrum. An upset to those rhythms from an unnatural evening spectrum can create a myriad of health issues in animal and humans.

It should be clear from the above the importance of choosing the correct spectrum for Kincardine’s artificial lighting system.

Scheduling^iv

Plants and animals often use length of night as a seasonal behaviour adjustment cue. For example, when to retract the flow of nutrients to leaves, when to migrate, when to store food for the winter, when and where to forage. Proper scheduling of night-time lighting can minimize the distortion of these vital cues.

We accept that urban outdoor artificial night-time lighting is a requirement in our modern society. But we must acknowledge that it comes with significant environmental costs. So we must be smart about it.

The new lighting system Kincardine is considering should be constrained so as to only put light where it is truly needed, only at a time when it is needed, at a level minimally sufficient to satisfy that need, and of a type that is least injurious to living things.

Our goal in writing this letter is to ensure that the environmental concerns are given a high priority in the decisions being made regarding technology and implementation. We implore you, as part of the project, please seek out and incorporate the advice from experts on the impacts of artificial light on biology.

Thank you for this opportunity to make our concerns known.

Jim and Christine Roberts,
Blair’s Grove

____________________

ⁱ JRASC June 2020, pp. 205-210, “The Biological Basis for Canadian Guideline for Outdoor Lighting 2: Impact of Brightness of Lighting” by Robert Dick.
ⁱⁱ JRASC December 2020, pp. 251-256, “The Biological Basis for Canadian Guideline for Outdoor Lighting 3: Impact of the Extent of Lighting” by Robert Dick.
ⁱⁱⁱ JRASC February 2021, pp. 8-15, “The Biological Basis for Canadian Guideline for Outdoor Lighting 4: Impact of the Spectrum of Lighting” by Robert Dick
^iv JRASC April 2021, pp. 72-78, “The Biological Basis for Canadian Guideline for Outdoor Lighting 5: Impact of the Scheduling of Light” by Robert Dick.