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Image credit: Daniel Mennerich
1182 words / 5-minute read
Summary: Most efforts to reduce light pollution to date have focused on the public sector. But as night skies continue to brighten around the world, private enterprise can play in protecting dark night skies. Corporate social responsibility (CSR) and environment, social, and governance (ESG) principles may be powerful — and thus far unappreciated — levers on the problem.
A recent paper in the journal Science made a splash in the world media. Headlines included "It's Getting Harder and Harder to See the Stars", "Starry Nights Are Disappearing", and "As 'skyglow' grows, study documents glaring global light pollution". The paper contained a startling result: in some parts of the world, the brightness of the night sky doubles every eight years. It represented a big increase compared to the rate of change reported as recently as 2017.
Light pollution is a problem in many parts of our world, its harms now thoroughly documented. Available technical solutions are cost effective, but the social and political will to put them into practice are missing. Laws and regulations can help, but they only go so far given that they are often not enforced well.
After governments, private enterprises are some of the most prolific light polluters in many communities. At the same time, those enterprises are finding that their environmental bona fides are increasingly scrutinized. Can the concepts of corporate social responsibility (CSR) and environment, social, and governance (ESG) nudge some companies toward doing better?
Beyond the buzzwords: what are CSR and ESG?
CSR and ESG are hot topics in the global corporate world. But what do they really mean? CSR establishes values and sets an agenda, while ESG turns that agenda into goals with measurable impact. In a sense, CSR makes up the "S" ("social") in ESG by operationalizing the vision that CSR establishes.
The actions of early 20th century industrialists like John D. Rockefeller and Andrew Carnegie exemplify CSR. They spent billions of dollars on social causes, the legacy of which remains with us to this day. ESG traces its roots to the South African anti-apartheid movement that began in the late 1950s. It only became well known in 2006 when the United Nations launched the "Principles for Responsible Investment."
CSR is qualitative due to the many nuances of measuring social impact. ESG criteria tend to consist of quantitative metrics. It provides a way for companies, investors and the public to check how well companies stick to the sustainability and corporate responsibility goals they set. The current understanding of ESG considers the environment a stakeholder in all businesses. No particular industry or sector is exempt.
This framework is not immune to criticism. A major disadvantage of CSR and ESG is that small businesses shoulder much of its costs. Some critics contend that they undermine the primary aim of business, which is to create (financial) value for shareholders. They can also draw unwanted scrutiny over ever aspect of a company's business. And in some cases, CSR/ESG initiatives can distract from the need for meaningful, systemic change.
Why companies care
The corporate world now ignores CSR and ESG at its own peril. Corporate boards increasingly seek advice on how to pursue these ideas. Some now see environmental concerns as among the stakeholders that their business affects.
But much of the pressure to do so still comes from the outside. One recent survey found that almost three-fourths institutional investors do not trust companies to achieve their stated sustainability and ESG goals. Investors and regulators alike are applying pressure on companies. And it's becoming hard for them to hide the environmental and social harms associated with their activities.
What about forces operating inside organizations? There is some evidence that companies prioritizing CSR and ESG principles have increased employee productivity and reduced turnover. Other data suggest that consumers, especially younger people, prefer to buy from companies that exhibit a strong sense of social responsibility. Failing to recognize this can even cost companies more in the long run.
How CSR and ESG may influence light pollution
Light pollution is an environmental issue at its core. It involves many known and suspected hazards to plants, animals and even people. With each passing year, the weight of the evidence grows bigger. And because the world still produces some 80 percent of its electricity from fossil fuel sources, light pollution is also a climate issue.
Light pollution arguably harms businesses' environmental stakeholders, yet it costs little to nothing to undo the damage. Many businesses will find it even saves them money to reduce their artificial light at night emissions in both their supply chains and at their facilities. Companies that fail to take advantage of these savings may be seen — pardon the pun — in a bad light. It may lead to accusations that they only care about higher-profile environmental issues. In turn, that implies that their assessments of environmental stakeholder needs are inadequate.
Wherever companies operate, they extract profits from those territories and communities. As the social significance of climate change rises, it is a disadvantage when the public perceives a company is doing harm rather than good. Those that do considerable business with governments may find these concerns turn into requirements. Planning ahead to be able to react quickly to a changing business landscape conveys a clear advantage.
There is even a nexus among ESG, land use planning, the public regulatory regime, and dark skies. In countries like Wales and New Zealand, large territories are under management as International Dark Sky Reserves. Both the central governments and local councils in those places are proactive in framing light pollution as an environmental concern.
From theory to action
What can companies do? They should put their own houses in order first. Audits of lighting practices and policies can reveal opportunities to reduce waste and lower light emissions. For instance, a retailer with large distribution centers might find that over-lighting of facilities threatens worker safety.
A review of their business models may show elements that generate significant light pollution. Changes can reduce their impact without undermining those models and the profits they drive. Companies that leverage the low cost of making these improvements will find that they can't afford not to do it.
One simple blueprint for developing CSR and ESG goals is to ensure corporate actions adhere to the Five Principles for Responsible Outdoor Lighting. This series of statements prioritizes protection of the nighttime environment by prescribing simple lighting concepts. It also suggests metrics that companies can use to chart their progress.
What holds back progress in this arena? As with much of the wider world of dark-sky advocacy, the main missing piece of the puzzle is awareness. Corporate boards that become aware of the harms of light pollution are more likely to develop policies that commit to its reduction. Investors and consumers can be important influences that raise awareness. Solutions may be as much bottom-up as top-down.
As the world becomes more socialized to the related challenges of climate change and sustainability, so it may be more likely to discover light pollution. Companies can either recognize this and act on it or risk exposure as a major source of the problem. Those that choose action will find the relevant technology advanced, the solutions plentiful, and the value proposition powerful.
Every company can benefit from a review of its policies and practices relating to outdoor lighting. Contact us today to learn how we can help your business understand its light pollution impact.
Thanks to Lee Mauger for helpful discussions as this post was coming together.
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Image credit: Fabrice Villard
483 words / 2-minute read
Every year, the International Dark-Sky Association (IDA) hosts International Dark Sky Week (IDSW). This is a weeklong event held during April that draws attention to the issue of light pollution, its harms and solutions. As it falls during Global Astronomy Month, IDSW is also a time to celebrate the night and the value of nighttime darkness. In 2023, IDSW takes place during the week of 15-22 April.
IDA is the world's foremost authority on light pollution and dark skies. Founded in Tucson, Arizona, in 1988, it aims to protect the night by educating the public about these issues. It also provides resources to those who want to improve outdoor lighting in their own communities.
"International Dark Sky Week is the time each year when we remind everyone about the value of protecting the night," said IDA's Director of Engagement, Bettymaya Foott. "It's fun and informative, and getting involved is easy."
The international community of dark-sky advocates celebrates the 20th anniversary of IDSW this year. A high school student named Jennifer Barlow of Midlothian, Virginia, originated the idea for an annual event in 2003. It began as "National Dark Sky Week" in the U.S., but the idea later spread to other countries. In the years since, organizations like the American Astronomical Society, the Astronomical League and Sky & Telescope magazine have endorsed it.
"Most of us have forgotten the legacy of the night sky as it seems to fade away behind the blanket of light pollution," Barlow told Sky & Telescope in 2006. "The universe is an important part of our history that should not be forgotten."
Image credit: Hoang M. Nguyen
IDA took over the annual promotion of IDSW in the past decade. It now consists of daily programming and events held throughout the week. In this way, the approach sustains attention to the issue. IDA also offers opportunities for those who want to become more involved in advocacy around dark-skies issues locally. The activities reinforce the idea that everyone can do something meaningful to reduce the impacts of light pollution.
The timing of the week matches the period when the lunar phase is waning after last quarter. That means the early evening hours are free of moonlight interference. Organizers encourage participants to go outside and see the night sky from wherever they live.
IDSW activities offer something for everyone. Because of the favorable Moon phase, it's a good time to make citizen-science measurements for the Globe At Night program. Having a look at the exterior lighting on one's home using IDA's self-assessment guide can reveal potential improvements. And anyone can use the platform of website, magazine and newspaper letters to the editor to express their thoughts.
Local groups increasingly host events during IDSW, including public lectures, night walks, star parties and more. IDA maintains an events calendar listing the details. Participants can also follow along on social media by using and following the hashtags #IDSW2023, #DiscovertheNight and #DarkSkyWeek.
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Image credit: City of Manhattan, Kansas
1297 words / 5-minute read
Summary: Chromaticity shift is affecting an increasing number of commercial outdoor lighting products. This may affect public perception of solid-state lighting and could change the nature of skyglow over cities. This post explores what it is, why it's happening, and what can be done about it.
It sounds at first like an alien invasion.
"The sky over the city of Vancouver was the color of a television tuned to a Prince concert."
"I've had people call and ask if this was because it's Halloween, or because their football team in that area wears purple."
"Street lights are mysteriously turning purple. Why is this happening?"
In many parts of the United States, residents of cities are watching their new light-emitting diode (LED) street lights behave strangely. While they started out bright white, many are now turning an unsettling shade of purple. They have "spawned theories online about everything from vampires to vaccines". The truth is much more mundane. But as Business Insider notes, "when LED streetlights start changing color for no apparent reason, it's a visual cue that we might need to rethink, just a bit, how we build the future."
Pretty or problematic?
The lighting world has come up with a term for what many people are seeing close to home: 'chromaticity shift'. It's a fancy way of saying that the color of a light source is changing. The usual context of the term is in cases where that change is not part of the design of a lighting product.
To understand why that matters, let's back up for a moment and look at how white LED light sources work. This technology has achieved incredible success, coming to dominate the lighting market in only about a decade. Its high energy efficiency and ability to be carefully controlled make it a lighting workhorse.
But the light it produces isn't really "white". Underneath every white LED is a blue LED. Its blue light shines on a material called a phosphor, which has a particular chemical composition. Depending on the chemical mix, the material gives off light of other colors. Allowing for some of the blue light to leak through, the other colors add with it to give the sensation of "white" light.
Some influences change the relationship between blue LED and the phosphor, or change the nature of the phosphor itself. The balance of colors emitted by the LED changes in turn. This can result in chromaticity shift. The perceived color of the resulting light depends on what has happened to the phosphor. Sometimes it happens when the material binding the phosphor swells or cracks. In other cases, heat changes the chemical characteristics of the phosphor. It's also possible for the capsule of the LED itself to scatter or absorb too much blue light.
An example of outdoor lighting shifting to colors other than purple. These lights beneath the canopy at a filling station have shifted from white toward green, indicating that the phosphors in the LED capsules have oxidized.
Whatever the cause, once chromaticity starts it's impossible to reverse. Correcting it requires replacement of the LED 'light engines'. Because these are now integrated into modern lighting products, it usually means replacing the entire light fixture.
A 2020 U.S. Department of Energy report found that evidence for the shift starts to emerge after only about 8,000 hours of operation. While this time of "emergence" has increased, it is still far less than the expected lifetimes of LED lighting products. An often-quoted figure for the life of an LED chip is about 100,000 hours, or roughly 20 years of service. Chromaticity shift often shows up after about only two years.
Lab measurements of white LEDs show a gradual shift in the color away from white after 6000-8000 hours of operation. Image credit: U.S. Department of Energy.
So why are many white LEDs turning purple? It seems because of a manufacturing defect that causes the phosphor to pull away from the blue LED chip. In 2021, the manufacturer, American Electric Lighting, told the EdisonReport, a lighting trade publication, "The referenced 'blue light' effect occurred in a small percentage of AEL fixtures with components that have not been sold for several years. It is due to a spectral shift caused by phosphor displacement seen years after initial installation." It has since replaced many of the affected lights under warranty.
Blues in the night
At first the problem might seem only one of appearances. AEL stated that light produced by its products suffering chromaticity shift "is in no way harmful or unsafe." There is no reason to think that the purple lights are somehow dangerous to people. But there are real concerns about how their light affects the nighttime environment.
White LED lights that have shifted toward purple are telling us that more of their blue light is escaping. This is especially evident in the images below kindly provided by Bill Kowalik and Cathie Flanigan of the Oregon Chapter of the International Dark-Sky Association. They show images of the visual appearance of both normal street lights in the city of Bend, Oregon, and those affected by chromaticity shift. For each image they show a spectrum of the light pictured.
Comparing the two, it's clear that the purple lights emit much more blue light compared to light of all other colors. Bill and Cathie write, "The measurements show that for the purple lamp, the blue peak is about 2.5x stronger than the peak of green- yellow-red wavelengths. In the normal street lamp, the blue peak is about 1/2x the peak of the green-yellow-red."
There is now a great deal of evidence that blue life is harmful to wildlife. In particular, in many species it disrupts the natural circadian rhythm necessary for wellbeing. We also know that blue light scatters better in the atmosphere than other colors. The strong scattering means that blue light is a main contributor to the phenomenon of skyglow over cities. Bluer light sources mean brighter night skies and fewer stars seen overhead.
The impact of shifting street lights can be reduced if cities replace them promptly. Failed lights are usually covered by manufacturer warranties, and cities are entitled to replacements at no cost. But the saga of chromaticity shift follows reports of other, widespread LED street lighting failures. For example, in 2019 the city of Detroit, Michigan, settled a dispute with the manufacturer of almost 20,000 of its street lights that failed not long after installation. The settlement did not cover the full replacement cost, leaving the city on the hook to the tune of $3 million. Replacing shifting street lights may come with similar costs.
The perils of being an early adopter
There is a bigger story here than just one of purple street lights. There are of course risks attendant to any emerging technology, some of which might not become apparent for years. Business Insider suggests that the problem for American Electric Lighting was sourcing poor-quality parts from overseas manufacturers: "Those vendors are typically building products at scale, trying to squeeze out every efficiency they can without infringing on the patents on the high-quality, higher-priced versions. Sometimes that makes for a less-good LED."
These are dollars-and-cents decisions for lighting manufacturers. In the last decade, market forces exerted a huge downward pressure on LED lighting prices. Converting the world's existing lighting to LED was a tremendous, once-in-a-lifetime opportunity. Responding to customer demand created supply issues, and companies looked toward what was both cheap and available. The quality of some of the electronic components used in their products simply wasn't high. And some companies are now obligated to provide very expensive replacements under warranty.
These cautionary tales should inform the next generation of advanced lighting product development. It calls into question what other elements of the infrastructure of cities, now so deeply dependent on technology, may be next to fail. In our increasingly interconnected world, purple street lights are a metaphor for the ties that bind — and sometimes fail -- us.
The color qualities of light are only one aspect of the decisions that local governments face when they decide to modernize their street lighting. For many tasked with making decisions, it can be a confusing topic to navigate. Our expertise and experience advising cities choosing new lighting can make the difference in the success of retrofit projects. Contact us today to find out how we can help your city.
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Image credit: Mike Knell
959 words / 4-minute read
When you hear the term "light pollution", what comes to mind? While it's actually a broad term encompassing effects both on the ground and in the night sky, most people think of it as the inability to see the stars at night. That effect in particular, called "skyglow", results from light emitted on the ground up toward the sky. That light scatters in the atmosphere, which redirects it back toward the ground. There it competes with starlight and causes the sky to look grayish and washed out.
Thanks to research described in a new paper in the journal Science, we know that skyglow is increasing around the world at a stunning rate. The study, published in January, found the rate of increase is about ten percent per year when averaged around the world.
Counting stars instead of lights
Researchers in Germany analyzed tens of thousands of observations made by citizen-scientists between 2011 and 2022 as part of the "Globe At Night" project. The organizers ask participants to first locate familiar constellations in the night sky. They present maps of those constellations showing differing numbers of stars to show varying degrees of skyglow. The participants decide among the charts which best matches their own local night skies. This provides robust estimates of night sky brightness that scientists can compare against other sources of data about light pollution.
Globe At Night charts for the constellation Orion. To estimate the brightness of the night sky, participants compare these charts to the night sky from their locations and find the best match.
The new work is the first large-scale analysis of the Globe At Night estimates. Until now, Earth-orbiting satellites provided the only global view of light pollution. Earlier studies involving satellite images concluded that light pollution on the ground grew at a much slower pace. A 2017 study concluded that the rate was around two percent per year in the first half of the last decade.
Satellites flying blind
The new estimate in Science looks up from the ground instead of down from space, which may explain some of the difference. The satellites used to gather the night-lights data don't see blue light at all. They were not designed to make light pollution measurements in particular, so their onboard sensors aren't ideal for the job.
Their insensitivity to blue light is a problem given how the color of light at night continues to change. Since around 2010, many cities across the world converted their stock of public lighting to new, white light-emitting diode (LED) technology. They did this in hopes of realizing major reductions in energy use and financial cost with these energy-efficient light sources.
But white LED emits a lot more blue light than earlier lighting technologies. Satellites thus tend to under-count the amount of light at night they receive in space. That same blue light also scatters more strongly in the atmosphere than other colors. All other factors being equal, that effect explains in part why nights are getting brighter.
A global composite view of the Earth at night in the year 2015 made from artificially colored orbital satellite data. The relative 'blindness' of satellites to blue light means images like this underrepresent the true extent of night lights on our planet. Image courtesy of NOAA/NASA.
Besides to the color issue, satellites also miss some of the light directed upward from the ground because it becomes skyglow. Since they are above the atmosphere, satellites only detect light rays that reach them. Some of those rays never make it because they're redirected back down to the ground. So while ground-based observers saw their night skies brighten in the past decade, satellites recorded a much slower rate of change.
Furthermore, some light sources emit in ways that makes it unlikely their light will be seen directly in space. Sources like lit windows of buildings and illuminated signs emit light toward the horizon. Those sources are among the most important contributors to skyglow, but very little light they emit gets to the satellites. And there is evidence that at certain hours of the night, those sources dominate light escaping from cities.
Visual observers on the ground sense at least some of the "missing" light that satellites don't see. That way of estimating the brightness of the night accounts for both the increase in light emissions and a trend toward bluer sources. Citizen-scientists also extend the reach of light pollution studies. It's often easier to recruit them to count stars where they live than place light sensors in the field. That is especially true in very remote locations around the globe.
Citizen science for global change
But even considering that volunteers provided about 50,000 measurements in the preceding decade, the information is incomplete. Vast swathes of land contained no observers at all. That left scientists to make informed guesses in places like Africa, where satellites suggest night lights are increasing the fastest.
Although the study authors note that known methods of reducing light pollution yield reliable results, current initiatives aren't producing results. This concerns light pollution researchers and activists alike. Skyglow is one symptom of a larger problem involving overuse of artificial light at night. We know it has negative impacts on everything from wildlife to energy use, traffic safety, and more. It's about much more than whether we can see the stars at night.
As more people realize the seriousness of the issue, governments are taking note. Countries like Mexico have recently classified light pollution as a form of environmental pollution. This can bring the mechanisms of existing environmental laws to bear on the problem.
The failure to reduce light pollution has real and lasting effects on communities. Wasted outdoor light at night involves measurable social and financial costs. Yet the new study authors admit that these messages about light pollution might heard by governments if the data were better geographically distributed.
More people participating in Globe at Night would improve the reliability of the results. If the number of participants increased by a factor of 10, we would begin to see trends on scales smaller than whole continents. As lead author Christopher Kyba said, "If we could do that, we would surely find places that are doing better than average, and we could try to figure out what they are doing right."
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Image credit: NPS / Will Pedro
753 words / 3-minute read
In January 2022 we wrote here about 'astrotourism', a kind of night-sky themed ecotourism, was "on the rise". The intervening year has seen this industry grow by leaps and bounds around the world. As the COVID-19 pandemic fades, people are hungry to see the world again and experience new adventures. For many who have never seen a starry night sky, an astrotourism experience fits the bill.
There are a few places in the world where this mode of tourism is already well developed. For example, the Mackenzie region of New Zealand has a thriving local astrotourism industry. Many places have the right mix of dark night skies and daytime allure, but few have achieved such success. Those that do stand to gain much in the way of economic development, particularly in rural and economically depressed areas.
The U.S. state of Utah is one of the exceptions. While famous as a winter playground for the "greatest snow on earth", tourists now flock to the Beehive State for other reasons. According to the Utah Office of Tourism, dark skies now have a higher public and media uptake than skiing. The magic of dark night skies above, with the celebrated beauty of the Utah landscapes and its vast public lands below, is a strong visitor enticement. That is especially true for families with children who have never experienced the splendor of the stars.
In a sense, the modern idea of astronomy-themed tourism started in this part of the world. In 1969, formal stargazing programs were first offered to the public at Bryce Canyon National Park. As word of the region's night skies spread, early efforts to commercialize the experience took root. Opportunities available to Utah astrotourists now run the gamut from guided, small-group stargazing to astronomy-themed river running and 'glamping' experiences.
While its full economic value to the state has yet to be quantified, there are reasons to think that Utah is already benefitting. One study, published in 2019, predicted that astrotourism will account for $6 billion worth of economic activity in the region during the 2020s. The surge in post-pandemic tourism means that number is probably on the low side of what's possible.
Utah ranks number one with more accredited International Dark Sky Places than any other state or province in the world. Its dry climate and often favorable weather yield some of the finest night skies in the developed world. Travelers come to Utah from heavily light polluted places such as the East and West U.S. coasts, Europe and Asia to experience this firsthand.
The government of Utah has taken notice, and it has begun to incorporate dark skies into the state's branding. For example, the Utah Governor has declared April as Utah Dark Sky Month for the past two years. And beginning in 2023 the state will offer a themed license plate to motorists. When seen during their travels to other states, it serves as an advertisement attracting more tourism.
An early design concept for the Utah dark-sky specialty license plate, making its debut in 2023.
Officials have come to recognize astrotourism as one of the most profitable sectors in the ecotourism industry. While famous for its "Mighty 5" U.S. National Parks set among the stunning scenery of southern Utah, daytime-only visits have a milder economic impact. Realizing that "half the park is after dark", astrotourism activities in and near the Mighty 5 offer further recreation opportunities to visitors. This not only adds significant value to visitor experiences, but it means more revenue for tourism operators and local governments alike. Even one night spent stargazing adds an overnight stay and two meals to a visitor's tab. This represents a highly profitable proposition.
The state's Office of Tourism developed a well-considered dark sky toolkit, debuting in 2022. One segment of that toolkit, "An Industry Guide To Astrotourism," offers a particularly powerful set of guidance and resources. As the field becomes increasingly professionalized, this level of state support helps bring new operators into the industry. It also grows a local knowledge base that can help with the development of new tourism products.
Utah has become a best-practice model for the economic development possibilities of astrotourism. It provides clear, actionable information to interested communities and their affiliated DMOs (Destination Marketing Organizations). To this it adds branded marketing elements that reinforce a strong connection between Utah outdoor recreation and night skies. The result is a recipe for success to which people in other parts of the world now look as an example to guide their own local efforts. Dark-sky tourism now has a bright future, and Utah leads the way.