Night-as-day in Canada

An urban sustainability study on light pollution and comparing how Montréal and Calgary size up

Toronto Édifice Pompidou [3296681032_226790162c_o] low crop

Prepared 9 March 2009 for Prof. Ernest Opoku-Boateng (JIE307Y1Y, University of Toronto).

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In this paper:
Introduction: the night of 2003
Night sky glow and sustainability: no harm done?
Only a nuisance to the night sky?
The health of night light
Criticisms of light pollution curtailment: myths
Quantifying light pollution: economics
Case review: Montréal
Case review: Calgary
Summary: a cleaner, darker city?

Introduction: the night of 2003

During the 2003 blackout that affected much of Canada and the U.S., millions of people could see the Milky Way — some for the first time. Was this inky darkness a cause for concern? Were urban areas more dangerous? Were there lingering effects aside from, obviously, being able to see less street and more sky? Could cities like Montréal and Calgary live with this every night?

This research weighs light pollution as an urban sustainability issue: is there a problem? If so, how is it problematic? To what degree does it affect those who inhabit the city or its hinterlands — particularly in Canada, which ranks among the highest in per capita electricity consumption globally (CIA 2008)? Are cities cognizant of the issues related to light pollution? Because this paper limits itself to two Canadian cities, have Calgarians and Montréalers confronted light pollution within their own jurisdictions? Has either city linked light pollution to urban sustainability policy? This comparison finds that both cities now acknowledge light pollution for different reasons, but neither has advanced turnkey remediation as part of an integrated sustainability plan. This may be attributed to a generally poor understanding of the ecological impacts of light pollution on urban form — certainly so compared to smog, poor transportation planning, hydrologic health, or soil contamination.

Night sky glow and sustainability: no harm done?

Before adding Montréal and Calgary to this discussion, it is necessary to address light pollution’s relevance in a sustainability context. The emerging lens of urban ecosystems analysis, or UEA, allows urban sustainability to be viewed in terms of the ways which “socio-economic, cultural and bio-physical factors” alter urban environments (Piracha & Marcotullio 2003, 2). With this lens, it becomes possible to recognize and develop frameworks of sustainable urban policy to mitigate and remediate the negative effects of human activity and how these impose on indigenous ecosystems.

These activities no longer are confined to a single locality: the greater the prevalence of unsustainable activity, the greater the likelihood that that activity implicates other groups whose geographic placement falls beyond the immediate siting of that activity (Piracha & Marcotuillo 2003, 5). It then becomes possible to conceptualize other modes of pollution in a similar context to, say, acid rain or strip mining, whose effects can be felt hundreds of kilometres away from the source.

The same implicates light pollution, as it constitutes an “alteration of the natural light levels in the night environment produced by man-made light” (Cinzano et al. 1999, 517). The phenomenon made possible by Edison was marvelled by those who first saw how it transformed the night: “Men fell on their knees,” and many “contemplated the new wonder of science as lightning brought down from the heavens” (Chepesiuk 2009, A21; Scigliano 2003, 60). Practically speaking, any artificial light can potentially pollute the night sky if unshielded or focussed in some way that it emits photons directly into the sky. Even so, indirect light reflected from properly focussed illumination can con- tribute to night sky glow. Eliminating it completely may not be possible. But bright nights are only a visible symptom of a much more serious iceberg now being acknowledged as a sustainability issue.

Only a nuisance to the night sky?

Light pollution reaches well beyond the ire of astronomers and irate residents who cannot sleep due to a neighbour’s glaring security light. While astronomers first mobilized to raise public awareness for what was originally a key obstruction to their research, scant concern was paid as to whether this artificial illumination altered ecosystems, interrupted biological circadian rhythms, affected public health, or even hurt municipal bottom lines (Riegel 1973, 1291). Dark sky advocates often ran into resistance from residents and city councillors who were more interested to brighten city streets and improve public safety perceptions. The few truces called were in localities whose sprawl had encroached on existing observatories (Fletcher & Crampton 1973, 275; Waldrop 1983, 247).

The health of night light

A new twist on the old battle between astronomers and cities comes from mounting research out- lining light pollution’s physiological impacts upon terrestrial and aquatic life. These are only beginning to be understood in earnest. Researchers studying zooplankton, humans, monarch butterflies, and others increasingly agree that nocturnal, non-celestial illumination triggers “alterations to natural diel” — the circadian rhythms of a 24-hour cycle — and for people, the body’s ability to repair itself nightly (Longcore & Rich 2004, 192; Moore et al. 2001, 781; Navara & Nelson 2007, 221). This “chronodisruption” prevents both nocturnal and diurnal animals from repairing, regenerating, and even feeding (Reiter et al. 2006, 357). When chronodisruption occurs, its effects can ripple with un- intended outcomes. Daphnia zooplankton ascend from deep water to feed on surface algae, but only in pitch dark when a full moon is absent; light pollution prevents this nightly feeding cycle, leaving algal blooms unchecked that in turn can suffocate other aquatic life (Moore et al. 2001, 781).

For humans, absolute darkness is needed for the body to produce melatonin, which aids in repairing damaged cellular activity (Navara & Nelson 2007, 216). Ocular photoreceptors signal to the pineal gland when to secrete melatonin — whose oncostatic (cancer-halting) properties, metabolic regulatory role, and immunity-boosting properties are well-documented; “light at night” (LAN) interrupts melatonin synthesis which, for women especially, correlates to a measurable elevation in breast cancer rates (Cos et al. 2006, 270; Kerenyi et al. 1990; 77; Kloog et al. 2008, 78; Navara & Nelson 2007, 216). LAN also disrupts the production of other hormones — in particular, serotonin, which implicates the increased incidence of clinical depression (Navara & Nelson 2007, 217).

These diverse studies concur that light pollution is an actor behind the escalation of these conditions, namely so in developed urban regions. The biological implications extend to public policy, ecological restoration planning, and forecasting the overall fitness (and productivity) of an urban population. If actuarial projections for a city’s overall life expectancy and level of health is negatively affected by a known variable — and that variable can be mitigated — then in the long run, it becomes the public’s interest and that of business to diminish the presence of that variable as much as possible. In this case, programmes to curtail light pollution seems the most logical starting point.

Criticisms of light pollution curtailment: myths

That said, NIMBY-like resistance from proprietors and elected representatives who try to link “dimmer” street lighting to a threat on public safety must be put out to pasture by data that refute these claims. The popular myth that brighter lights correspond to decreased crime appears to be at odds with field research that indicates otherwise and with statistics logged during the 2003 Blackout (Clark 2005, 198; Morrow & Hutton 2000, v). Even Jane Jacobs (1961, 42) challenged this myth a half-century ago: “unless eyes are there, and unless in the brains behind those eyes is the almost unconscious reassurance of general street support in upholding civilization, lights can do no good.” Further, the pinkish high-pressure sodium (HPS) streetlights in many locations are ill-suited to the human eye’s night vision faculties which are best optimized for bluer frequencies (Harder 2004, 22).

Quantifying light pollution: economics

All the same, policymakers, accountants and environmental advocates are likely to spar over hard figures and what they mean in the context of light pollution. The trend of rationalizing decisions based on long-term benefit to business invites an ethical question raised by Coase (1960, 2):

“If we assume that the harmful effect of the pollution is that it kills the fish, the question to be decided is: is the value of the fish lost greater or less than the value of the product which the contamination of the stream makes possible. It goes almost without saying that this problem has to be looked at in total and at the margin.”

Sea-level artificial night brightness map of Québec, Ontario, and New England (source: Cinzano et al., 2001)

Figure 1. Sea-level artificial night brightness map of Québec, Ontario, and New England (source: Cinzano et al., 2001)

This paper has already reviewed a body of research which draws a direct connection between biological health and light pollution. Meanwhile, widespread policy on minimizing light pollution has not occurred. Why? Positions advanced by astronomers have gained little traction, because in the minds of shareholders and citizens, these consequences do not appear to harm their bottom line, be it financially or socially. As Coase (1960, 44) further elaborated: “The cost of exercising a right (of using a factor of production) is always the loss which is suffered elsewhere in consequence of the exercise of that right — the inability to cross land, to park a car, to build a house, to enjoy a view, to have peace and quiet or to breathe clean air.” He concluded that the rights of property owners “are not unlimited” (Coase 1960, 44). Applied to light pollution, it is now possible to distinguish far-reaching support for reduction on both sides of the economy-versus-social justice equation.

Intrepid efforts by astronomers to raise awareness did succeed in establishing early, yet valuable baselines for estimating the roughly 20 to 30 percent of total hydro output consumed by lights; from this, it became possible to investigate the economic unsustainability of light pollution (Berry 1976, 111). Hunter and Crawford (1991, 90–1) calculated that 2.5 percent of total hydro usage (in the U.S.) is consumed by outdoor lighting, and of that, about 30 percent shines either directly or indirectly into the sky. In 1991 figures, at those consumption levels, they conservatively estimated that:

“58 billion kWh [n.b., 58 TWh, or terawatt-hours] of electricity is used annually for night lighting. Because 15 percent of this lighting is for light that is going directly up into the sky, 8.7 billion kWh of electricity, or the equivalent of 8.2 billion pounds of coal, are consumed annually solely to brighten the night sky. This directly costs the country (using an average price of 7.40 cents/kWh) $644,000,000 per year. We also spend another $644,000,000 annually on lighting that is reflected into the sky. The actual total money spent is probably higher because street and highway lighting by themselves have an average cost of 10.21 cents/kWh” (Hunter and Crawford 1991, 91).

The Central Intelligence Agency’s World Factbook 2008 estimated that Canada’s hydro consumption in 2006 totalled 530 TWh; production-wise, 28 percent of hydro output originated from fossil fuel sources and nearly 58 percent from hydroelectric generation. The Hunter-Crawford method of 2.5 percent share for outdoor lighting carries to 13.25 TWh. Of this, the 15 percent emit- ted directly into skies as light pollution nationally amounted to 1.9875 TWh per annum, and the reflected amount doubled that to 3.975 TWh.

Survey estimates are not readily available for municipal-level figures, so Statistics Canada’s 2006 census count is being used to estimate rough, per capita costs and consumption levels for light pollution [Tables 1 & 2]. For Montréal and Calgary, hydro rates are derived from Hydro-Québec’s (2008, 4–5) North American survey of electricity rates in major markets. Three regional reference cities are also included. Mean estimates used are based on rates for residential and large-power customers. Nonetheless, Walker (1977, 405) warned that “the fact that a linear relationship exists be- tween . . . street lighting and population does not conclusively demonstrate the existence of a linear relationship between the total luminous outputs of the cities and their populations.”

Sea-level artificial night brightness map of B.C., Alberta, and the U.S. Pacific Northwest (source: Cinzano et al., 2001)

Figure 2. Sea-level artificial night brightness map of B.C., Alberta, and the U.S. Pacific Northwest (source: Cinzano et al., 2001)

Limitations with this model are manifest by simplified assumptions of actual consumption and illumination within a metropolitan area, as emitted light comparisons can only be made between cities whose economic conditions are comparable (Walker 1977, 405). Thus, hydro usage patterns that inevitably vary with economic conditions cannot be represented by this method. Absent primary field data, this exercise must settle on a flat, inhabitant-proxy level of consumption irrespective of local hydro rates, making usage more or less appear the same — about 125 kWh — for all CMAs (and 97 kWh for American MSAs, such as New York). This poorly reflects real hydro consumption levels, total street lighting units in use, regional climate heating/cooling demands, municipal by-laws on lighting rules, and types of lighting and wattages used (Sector Sustainability Tables 2008, §4.5.2). It is also unable to adequately reflect specific initiatives undertaken locally to reduce light pollution. To do this would require field inventories for each census tract to index localized variations.

But what is established is a rough baseline for investigating a city’s fiscal outlay against the light pollution it emits. It supports linking those data to other UEAs on concerns like greenhouse gas (GHG) emissions. One can reliably deduce that lower kilowatt-hour rates deter consumption less effectively than higher ones, thus explaining Montréal’s disproportionately potent light pollution foot- print rivalling that of New York City’s [Figure 1], whose population is over five times greater but whose average kilowatt-hour rates are 3.15 times more costly (Fazekas 2005, 28; Larivière & Lafrance 1999, 61). By the same token, Calgary (and much of Alberta) emits a significant light pollution footprint, especially when compared to nearby Vancouver and British Columbia [Figure 2] — even as kilowatt-hour rates are significantly more costly in Calgary than in neighbouring Vancouver. This may be a visual example of differing economic situations underscored earlier by Walker.

Case review: Montréal

View of a suburban Toronto night sky during the 2003 Blackout (source: Todd Carlson, 2003)

Figure 3. View of a suburban Toronto night sky during the 2003 Blackout (source: Todd Carlson, 2003)

Measures to reduce light pollution in and around Montréal have largely remained confined to lo- calized interests within the astronomical community. L’Observatoire du Mont-Mégantic (OMM) is situated about 225km east of Montréal and is far enough away that most light pollution affecting observatory visibility is emitted by small towns near the mountain-sited facility and from the city of Sherbrooke, located between the Montréal CMA and OMM (Legris 2007, 307). Nevertheless, partnerships between OMM and local towns like La Patrie have succeeded in town lighting upgrades to reduce light pollution glow (Legris 2007, 307–8). In the Vaudreuil-Soulanges MRC (municipalité régionale de comté, or regional county municipality) just west of l’Île-de-Montréal, one resident asked his local government to enact light pollution by-laws to reduce “the high costs of electricity” (Kingstruthers 2007). The argument seems logical, but the resident, an amateur astronomer, argued on the basis of economics in a province enjoying some of the lowest hydro rates on the continent. Crelin (2002) explained that effective political selling points need not be vague or confrontational to be provocative: before-and-after case study photos where lighting policy was implemented and, most compellingly, using a small lamp to demonstrate light glare to an audience can sway minds far more quickly and effectively than points made via verbal, written, or research-backed approaches alone.

Montréal, which since 2006 has operated as 16 separate municipalities under a legacy agglomeration agreement to manage infrastructure services (such as sewage and street lighting), was until very recently mute about light pollution (Ville de Montréal 2006, 47). Sea-level artificial night sky (SLANS) brightness maps compiled in 1997 to produce the first world atlas on light pollution show how Montréal’s light pollution footprint matches that of New York City’s (Cinzano 2001, 691). What makes it particularly remarkable is how these similarly sized and intense footprints underscore Montréal’s lighting profligacy: as noted earlier, its population is just under a fifth (19.32%) that of New York City’s (Statistics Canada, 2006; U.S. Census Bureau, 2007). But the mean $0.05577/kWh rate that Montréalers pay runs a third (31.67%) the (CAD) $0.1822/kWh cost that New Yorkers do (Hydro-Québec, 2008). Québec’s ability to generate electricity cheaply, a function of major hydroelectric dams completed during the late 20th century, correlates to substantially greater lumens: high consumption is fiscally less prohibitive relative to other North American cities (Dutil 2001, 134).

As recently as 2006, Montréal’s municipal budget plans specified allocating $9 million for “upgrading” its street light infrastructure, but it does not explain what this might involve (Ville de Montréal 2006, 54). The city government’s official acknowledgement of its light pollution footprint has been slow in the making and is only very recently being mentioned in official capacity. A January 2009 revision to the Montréal Master Plan broadly acknowledged the “growing problem of light pollution,” adding that it “entails wasteful and costly overconsumption of energy and an unwanted intrusion of light in living environments” (Ville de Montréal 2009 [2004], 130). Published research linking light pollution’s negative effects on public health and ecosystems is not mentioned as a rationale. The 2009 update promises general implementation measures for curtailing light pollution, but lacks specifics on when, how, and what capital may be allocated to reduce it.

Given this, Montréal is only now in the early stages of confronting light pollution. The Montréal Master Plan update opens discourse on new, effective strategies to reduce excess illumination. Coincident are emerging global economic conditions which are increasingly pressuring governments to trim away operational budgetary waste. This bodes favourably for cities now actively tabling light pollution remediation policies. Arguments for greater economic sustainability by literally trimming millions of dollars annually becomes a politically valuable bartering tool for negating light pollution. Montréal has yet to embark down this path, but Calgary, as is about to be discussed, has.

Case review: Calgary

View of the same after power was restored (source: Todd Carlson, 2003)

Figure 4. View of the same after power was restored (source: Todd Carlson, 2003)

Not surprisingly, light pollution remediation in Montréal has advanced at a slower pace than in Calgary, where hydro, at $0.1199/kWh, is more costly. Calgary’s incentive to reduce wasted light emissions thus has rested on economic imperatives. Given Alberta’s hydro rates, that a provincial city would implement efficiency measures to lower its operational costs is not remarkable. Unlike Montréal’s cheap access to hydroelectric power, Alberta relies on burning coal for generating much of its electricity (CEA 2006, 13). The City of Calgary created the EnviroSmart Streetlight retrofit programme in 2001 to embark to convert existing street lighting fixtures from drop-lens, “cobra-head” luminaires (notorious for creating light pollution) to flat-lens luminaires designed to direct illumination strategically, to minimize stray light, and to reduce wattage levels while maintaining comparable desired illumination at street level (City of Calgary Roads 2004, 3). A major motivation to embark on this upgrade project was predicated on long-term cost savings for hydro usage, and it embodies the city council’s adoption of the Triple Bottom Line approach for meeting mutual sustain- ability objectives on economic, social, and environmental fronts (City of Calgary 2005, 2; City of Calgary Land Use Planning & Policy 2006, 3; City of Calgary Land Use Planning & Policy 2007, 3).

Summary: a cleaner, darker city?

Montréal and Calgary both share an opportunity to arm themselves with clearly worded planning policies that articulate an imperative to reverse municipal-regional light pollution: leaving matters as-is looms as a liability that may hurt each city’s global standing in the long run, as linkages be- tween light pollution and ecological maladies (upon habitats and residents alike) undermine other sustainability initiatives. If for instance a plan to restore local aquaculture from past industrial activity cannot proceed because lunar-sensitive plankton, essential for the local food chain, cannot thrive and feed on phosphate-fed algal blooms, then algal-suffocated aquaculture cannot sufficiently bounce back as hoped.

Thus, sustainability initiatives must holistically dovetail light pollution reduction into part of a larger turnkey strategy. Not only is this necessary for sustainability generally, but if major economic centres like Montréal, Calgary, and even Toronto hope to approach ecological transparency, then it must be coincident with the ability to walk outside on a clear night and see the Milky Way [Figures 3 & 4] without having to strain. Only then will it be readily apparent whether progress on removing “day” from the night sky is actually working.


Estimated light pollution yields & metropolitan costs

Table 1. Estimated light pollution yields & metropolitan costs

Light pollution footprint

Table 2. Light pollution footprint


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