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.

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. ​

​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.

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. ​

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.

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."
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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.

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.

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. 

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.

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. 

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.

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.

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."

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.

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.