LIGHT POLLUTION - How does it work?

Image provided by NASA

Image provided by NASA

Written by: Ryan Nemeth

Published In: Terratory Journal

What do Thomas Edison, hormones, sleep apnea, astronomy and circadian rhythms have in common? If you guessed that all share some connection to global light pollution, then you are either way too smart for me or you have too much time on your hands. It may be a new concept for some, but you should know that light pollution is a real thing and does exist. Light pollution is defined as an unintended brightening of the night sky that is caused from excessive, misdirected or obtrusive light. This form of pollution distorts colors of the night sky and interferes with our ability to see the stars as a result of sky glow. Furthermore, light pollution disrupts the environment at large by intervening in the natural daylight and night cycles that help to drive many necessary biological functions in nature.  

The story and evolution of light and the unintended consequences of light pollution begin with fire. Historical records reveal that our human preoccupation with carrying and containing sources of fire and light far predate the first civilized societies as both heat and light are vital to our human existence. In fact, Darwin himself considered language and the ability to create fire the two most defining evolutionary qualities of the Homo Sapiems. Thus, it is not too surprising to learn that the earliest known stone lamps have been dated to the Pleistocene epoch and are thought to be approximately 40,000 years old.  The take away: where humans go, light follows.

So you ask, what is light? Visible light is the small range of electromagnetic radiation that is detected by our eyes. This form of light is comprised of photons that are emitted when energy sources release their energy in the form of electromagnetic radiation (EMR).  Not surprisingly, some energy and light emitting sources are more efficient than others in producing light photons.  Subsequently, humans have developed and adopted many combinations and forms of energy and light emitting technology. The abbreviated history of light and the trajectory of its development follows a path akin to this; Wood fire and torches 125,000 B.C., stone lamps 40,000 B.C., oil lamps 4500 B.C., candles 3000 B.C., first crude kerosene lamp 900 A.D., gas lamps 1792, incandescent lamps 1874, the first incandescent lighting system based on AC current 1886, mercury-vapor lamps 1901, neon lamps 1910, fluorescent lamps 1926, and LED lamps 1962.

What might be surprising to many, given the brief timeline of electric lighting, is the fact that electric based derivatives of light did not show up until the late 1800s. Furthermore, it is somewhat startling to think that humans have managed to whitewash much of the globe with artificial light in just a mere 150 years. You should know that both electric lights and gas lamps are products of the industrial revolution and these inventions marked a huge paradigm shift in the way that light was produced, transmitted and consumed. For the first time in history, we (humans) no longer had to tend a fire to light our world.  We had systematically engineered a way to turn a switch and walk away.  The intended consequences were that society could now remain productive 24 hours a day on a diurnal cycle void of sun. Thus, the industrial revolution and the invention of the gas lamp marks the spot in our history where humanity made a considerable lifestyle break from productive work hours that were dependent on the light of the sun. Coincidentally, the development of artificial light also coincides directly with our larger global transition from agricultural to industrialized economies.  Thus, the role that artificial light played in our larger socioeconomic transition and continues to play in defining and shaping our urban existence should not be discounted.

From the dawn of civilization, fire in the home and light were often one and the same. Wolfgang Schivelbusch stated in his book Disenchanted Night, “When the house lost its hearth fire, it lost what since time immemorial had been the focus of its life.'' This paradigm shift marks a rapid progression in the way that society consumed light in their homes as well as their businesses. As one can imagine, families no longer had a need for gathering around a single source of heat and light. The once vital community chores of chopping wood and tending the flame suddenly disappeared. Gas lamps, railroad access and utilities (water and gas) were suddenly available in many homes within a very short span of time.  One can only speculate just how much these inventions changed interpersonal communication, psychology and the overall orientations of the family unit and the broader community as we were suddenly freed from necessary but burdensome chores. If one is inclined to ponder the degradation of family and the loss of community in the modern world, I would suggest that the investigative journey start here. The unintended consequence of artificial light was a large societal shift resulting from newly lite environments that encouraged exploration, access, independence and new forms of community outside of the home. These newfound freedoms propelled individuals to seek out taboo and forbidden dimensions of the night as well as productive nocturnal environments, this lead to a dramatic increase in the hours of lighting (energy) that society consumed.

Paradoxically, something very interesting and troublesome transpired as industrial societies began to free themselves from a dependency on land and agricultural based orientations. This massive industrial transition created an unquenched need and thirst for more energy.  Industrial economies suddenly needed fuel and stores of energy for their factory based infrastructure, machine based productivity, transportation of goods and materials and also for the coinciding urban growth. To this day, progress in the global industrialized economies of the world remains highly dependent on the security of cheap and renewable demand driven energy stores. Furthermore, these same energy requirements hold true for our newer service based economic models. Looking back, what prompted dramatic change in the late 1800s was our ability to create and extract cheap sources of energy (coal, petroleum, natural gas, and hydro-electric power) and to transmit this energy over long distances to those in need. This industrialized shift in the transmission and consumption of energy meant that family units, communities and individuals no longer had to secure their own power. One of the biggest ramifications for life under this new model was that society no longer bore the burden to harvest, maintain and manage personal energy stores.  Due to the gains associated with the specialization of labor, it became more efficient for centralized organizations to secure and manage energy resources for us.  Thus, energy consumption transitioned to a place that was no longer dependent on personal productivity, but a function of market based supply and demand and relevant energy pricing structures. 

The advance of the industrialized market-based energy economy was an amazing breakthrough for society both in the form of productivity and leisure. However, because energy was and still is cheap relative to wages in the developed world, there remains very little downward market price pressure to discourage consumers into actions of energy conservation.  A consequence being that it is cheap to leave the lights on. As a result, many of us in the developed world still continue to do so. Fast-forward one hundred and fifty years and it turns out that wealthy countries with vast energy stores and resources are those that contribute most to global light pollution. Looking at lighting maps of earth from space reveals that the United States, Europe and Japan are some of the worst light pollution offenders on the planet.  The patterns and disbursement of global lighting make it fairly easy to conclude that light pollution is not simply a result of population density, but also a by-product of wealth. Thus, our massive and impersonal energy systems driven by consumer based cultures and failed resource management policies have yielded a modern world begging for improvements in lighting efficiency and the way we light our world.

According to a report on global light pollution published in the Monthly Notices of the Royal Astronomical Society, two-thirds of the U.S. population and more than one-half of the European population have already lost the ability to see the Milky Way with the naked eye. Moreover, 63% of the world population and 99% of the population of the European Union and the United States (excluding Alaska and Hawaii) live in areas where the night sky is brighter than the threshold for light-polluted status set by the International Astronomical Union. In translation, the lumen output from artificial light measures greater than 10% of natural sky brightness above 45° of elevation, confirmation that our world is filled with light pollution.

So the question is why care, what are the broader ramifications of light pollution on the environment and society, if any? Astronomical communities and those who care about seeing the stars at night have long been at the forefront of the dark sky movement and other light pollution reduction initiatives.  However, for many, the interfering glow of city light that prevents us from seeing the stars at night remains inconsequential, trivial and seemingly non-necessary for a vibrant and knowledgeable earthly existence. Thus, it is easy to understand why light pollution initiatives might be easily dismissed as unimportant or inconsequential. However, if one is willing to dig, the problem of light pollution remains larger and much more complex than one might first suspect.

For many eons, life has relied on the predictable rhythms of day and night created by earthly interactions with the sun. This 24-hour day and night cycle, known as the circadian cycle, affects physiologic processes in organisms as it is encoded in the DNA of humans, plants and animals. Studies of humans reveal that circadian cycles interact directly with approximately 10-15% of our genes. This interaction shows up in brain wave patterns, hormone production, cell regulation, and other vital human biologic activities.  A few of the documented and associated human disorders linked with disruptions in circadian rhythm cycles include depression, insomnia, cardiovascular disease, and cancer.  Beyond human aspects of light pollution, plants and animals also depend on the earth’s daily cycle of light and dark to govern life-sustaining behaviors such as reproduction, nourishment, sleep and protection from predators. Thus, artificial light in the night sky can have a very disruptive effect on the natural rhythms that help to create cyclical order and biological balance in our world.

Case in point, migrating birds seems to be heavily affected by glare and sky glow associated with artificial lighting in the night’s sky.  In North America alone, about 200 species of birds fly migration patterns during the night.  When inclement weather and low cloud cover is present, birds demonstrate that they are routinely confused in their passage and navigation near brightly lit buildings, communication towers and other pervasive landscape structures.  Each year in New York City alone, about 10,000 migratory birds are injured or killed by crashing into skyscrapers and high-rise buildings. Current estimates for the number of birds that die from collisions across North America range widely from 98 million to close to a billion. However, the U.S. Fish and Wildlife Service estimates that 5 to 50 million birds die each year from collisions with communication towers alone.  Expanding and extrapolating from these numbers to our larger global environment yields staggering numbers of loss for migratory birds. Thus, the coinciding death and birth rates as well as natural predator and prey relationships that interact with migratory bird populations have dramatically shifted as a result of artificial light. What humans must comprehend is that light pollution can and does have dramatic implications for the vitality of many species of plants and animals. It should be noted that there are numerous other nocturnal animals such as bats, frogs, turtles, fish, and rodents that also have been directly and adversely affected by light pollution. This negative interaction with nightlight extends even further into insect species as well as plants.  In summary, the effects of light pollution are comprehensive and non-discriminating in the biological world.

Take for example, the changes in human patterns of sleep that have coincided with the industrial revolution and coinciding lighting boom. The sleep pattern that was the norm before the invention of electric lights is no longer the norm in countries where artificial light extends the day. In the 2005 book At Day’s Close: Night in Times Past, historian Roger Ekirch of Virginia Polytechnic Institute described how before the Industrial Age people slept in two 4-hour shifts (“first sleep” and “second sleep”) separated by a late-night period of quiet wakefulness. Thus, sleep cycles as governed by melatonin cycles that correlate to periods of light and dark were very different in the Pre-Industrial Age. Could the rise of endocrine related disorders, sleep disorders and other human diseases simply be related to the irregular circadian cycles and corollary gene, endocrine and immune responses in the body?

The evidence that indoor artificial light at night influences human health is fairly strong, but how does this relate to light pollution? The work in this area has just begun, two recent studies in Israel have yielded some intriguing findings. Both studies used satellite photos to gauge the level of nighttime artificial light in 147 communities in Israel. The data was collected and researchers then overlaid the photos with a map detailing the distribution of breast cancer cases in these areas. The results yielded a statistically significant correlation between outdoor nighttime artificial light and breast cancer, even when controlling for population density, affluence, and air pollution. Women living in neighborhoods where it was bright enough to read a book outside at midnight had a 73% higher risk of developing breast cancer than those residing in areas with the least amount of artificial lighting outdoors. Clearly this research is eye opening, yet the data merely demonstrates statistical correlation and not causation. In other words, don’t go freaking out just yet. Rest assured that researchers are fast tracking to connect the dots and larger communities of health organizations are starting to ask questions with the intention of seeking answers.

It would be very hard to refute the fact that artificial light has benefited society by extending the length of the productive day while offering more time for recreational activities that require light. However, when artificial outdoor lighting becomes inefficient, annoying and or unnecessary, it is nothing more than a pervasive form of pollution. Many environmentalists, naturalists, and medical researchers consider light pollution to be one of the fastest growing and most intrusive forms of environmental pollution. Furthermore, it should be evident that chronic exposure to this form of pollution can lead to negative and potentially deadly effects for many creatures including amphibians, birds, mammals, insects, plants and humans.  In 2008, the U.S. National Institute of Health (NIH) initiated its first multi-disciplinary research project on light pollution, this was a preliminary step to understand the comprehensive effects of light pollution and to try and corral a problem that is traveling at the speed of light. For some, the NIH’s involvement serves as evidence and acknowledgment of a much larger systemic problem.  This being said, light pollution is still way down the list of important environmental issues needing further research and study.  The use of excessive or unnecessary lighting also constitutes a waste of energy that is contributing directly to the release of carbon dioxide emissions and the warming of our global atmosphere. If you are at all inclined to believe that there are minimal consequences associated with leaving your lights on, think again!

How can you do your part to reduce Light Pollution?

One helpful way to reduce light pollution is to use a Dark Sky Compliant Fixtures, many new LED fixtures are design to be dark sky compliant.

Wall Pak

Wall Sconce



  1. Adler, Jerry (2013). Smithsonian Magazine. Reference 1

  2. G. A. Davis & J. D. Keller (2014). Reference 2

  3. Maddox, B. (1989). Reference 3

  4. Henley, J. (2009). Reference 4

  5. Chepesiuk, R. (2009). Reference 5




The Illumination Engineering Society has recently published an new and improved color rendition metric called TM-30. This highly precise and science based method is a step up from it's predecessor method, CRI.


Objects don’t have an inherent color, but rather reflect different amounts of energy over the visible spectrum. That means that the spectrum emitted by a light source changes the way objects appear. Color rendering describes this phenomenon. By using color rendering metrics, we can assign ratings to light sources using a set of standardized color samples. Although the objects in a given space won’t exactly match those of the standardized color samples, metrics can give us a good idea of performance and simplify comparisons.


TM-30 uses state-of-the art scientific advances in color science. As a result, it is more accurate than the CRI, especially for narrow-band spectra where the CRI can fail.  TM-30 provides more accurate information such as a fidelity index Rf which replaces the CRI index and indicates whether colors look natural. Lastly, TM-30 also provides more insight into the gamut index Rg which indicates a color's saturation and an accuracy graphic which gives advanced information about the rendering of specific colors.


TM-30 was developed by the Illuminating Engineering Society’s (IES) Color Metrics Task Group. The Task Group was comprised of seven voting members with backgrounds in lighting research, manufacturing, or specification. The Task Group worked under the IES Color Committee, which subsequently voted to approve the document, along with the IES Technical Review Council and IES Board of Directors. Majority approval was required at each balloting step. In total, more than 30 people voted on the TM-30 document, with more than 90% approving.


TM-30 includes a measure of color fidelity that is analogous to the CIE general color rendering index Ra, which is commonly referred to as CRI. It is possible that TM-30’s Rf will supplant Ra, if it achieves widespread use in the industry. However, CRI was developed by the CIE, whereas Rf was developed by the IES. The CIE is currently developing new color rendering measures, which may or may not replace CRI.


CRI is the common name for the CIE’s general color rendering index Ra. Like CRI, TM-30 Rf is a measure of average color fidelity; however, TM-30 Rf addresses many of the scientific shortcomings of the older metric, which was first adopted in 1965. Two of the main differences are the color space in which the colors are evaluated (CIE U*V*W* versus CAM02-UCS), and the number and type of samples considered (8 versus 99). Whereas Rf was formulated to have approximately the same scale as CRI, there is usually a difference in scores for individual sources, due to the underlying spectral differences. In particular, sources with narrow spectral features that were optimized for the samples used in CRI typically have lower Rf scores than CRI scores. Similarly, CRI is systematically biased against sources that increase red chroma, which can be particularly detrimental when attempting to identify preferred sources; this is primarily due to the color space used for CRI.

The color space, chromatic adaptation transformation, quantity of color spaces, and type of color samples all contribute to differences in score for Rf and CRI [1, 2]. Each contributes anywhere from minimal to more than 8 points difference in score for any given source.


  1. Smet KAG, David A, Whitehead L. 2015. Why color space uniformity and sample set spectral uniformity are essential for color rendering measures. Leukos 12(1–2):39–50.
  2. David A, Fini P, Houser K, Ohno Y, Royer M, Smet K, Wei M, Whitehead L. 2015. Development of the IES method for evaluating the color rendition of light sources. Opt Expr 23(12):15888.

LEDs Emulate Sunlight

Problem with Artificial Lighting and Sleep?

Sleep.  We all need it.  Before lightbulbs and artificial lighting were commonplace, humanity relied on the sunlight to decree our sleepy and wakeful times.  Light bulbs today help all sorts of people work, play, move, and think at times and in places where the sun isn’t shining so bright.  Even so, the sun still carries an effect that our body’s circadian rhythm responds to.

We forget to realize that our body’s internal clock can be negatively offset by artificial light, especially after habitually long periods of exposure before trying to fall asleep.  Light affects our body and mind’s energy, sleepiness/wakefulness, and cognitive function.

What you might have not known though is that different light affect us differently.

Blue light resembles daylight, and is often an indicator to our body to be awake and become energetic.  Elongated exposure to blue light can also reduce melatonin production, making it harder to fall asleep, even after you switch off your lamp or turn off your screen.  This is why the blue light from smartphones, computers, and TV screens can cause restlessness.  CFL lights, fluorescent tubes, and some LEDs produce a blueish light and even some incandescent lights can have the same effect.

Warm light, on the other hand, is better suited for the nighttime before rest.  Warm light, especially at dimmer levels, is better for melatonin production and is observed in incandescent lights, certain LEDs, and even some fluorescent lights.  A reddish coating can sometimes be added to the bulb to reduce the blue color and create a warmer light as well.

Solution for Better Sleep, Using LEDs!

While being conscientious of the lights you use in respect to time of day is an option, strides in lighting innovation are making things more body clock-friendly for light bulb users.  This creative move is manifested in new and upcoming LED light bulb designs.

The “Silk” light by Saffron, for example, tackles this problem head on.  The Silk bulb is an LED light that sinks your body clock with the sun’s shifting spectrum of light.  It does this by using Wi-Fi to detect your geographical location and then shines the correct lighting in accordance with the sun’s current placement.  The morning sun has more of a blue-white light while the evening sun has more of a red-warm light – The Silk light emulates this shifting effect to resemble a natural, organic lighting experience.

Not a fan of the winter blues?  This LED Silk light, by works of the Silk Light app, can be customized to fit the shifting sun spectrum of locations other than your own.  For example, if you are in the cloudy winter Portland, you can set the Silk light to fit the shifting sun patterns of Honolulu.

Another light by Saffron called the “Drift” light, also seeks to improve sleep – this time, by emulating a sunset.  Upon the user’s flip of a switch, the LED Drift light starts a 37-minute dimming period, closely resembling the 37 minutes it takes for the sun to set.  This helps people fall asleep by the natural body clock reaction to what appears to be a sunset’s light fading away into the night.

The awesome power of LEDs make this all possible!

The Aura, by Withings, is a large LED light that uses the same blue-to-warm lighting shift with the added functionality of a custom alarm clock and a mattress sensor.

The CoeLux LED goes a step further by emulating the Rayleigh scattering, the visual phenomenon of blue sky created by the sun and air particles.

Pacific Lamp’s Warm Dimming Bulb!

Pacific Lamp Wholesale now has the newest generation of “Warm Dim” LED lights.  These bulbs behave like traditional incandescent light bulbs that go to warmer and softer when dimmed – Our LEDs emulate the same effect and put up a great, comforting display that defines a “warm welcome” to keep you and guests feeling cozy, while saving power and reducing cost.

Come see our warm dim LED lights on display at our showroom, open to the public!

Here are the bulb specs:

SKU: 9.5A19DIM/LED/2700K-2200K/8CCTD/120 volt

Type: Green Creative lamp, standard E26 base (Dimmable)

Purchase these warm dimming bulbs today to create an extraordinary ambiance for all occasions.

LEDs Innovation Continues

As you can see, LED lights are finding a suit in simple lighting application as well as more advanced lighting options to aid both our health and well-being.  LEDs truly are the leading light bulbs for technological innovation that continue to reveal a bright future.

As a wholesaler of LEDs, Pacific Lamp is especially excited for what the future holds!

U.S. Drivers Could Go Electric

One of the biggest hurdles to getting more electric cars on the road is “range anxiety,” the worry people have of their car battery dying before they get to a charging station. A new study should help brush those fears aside.

Most American drivers do not go beyond the distance that today’s electric cars can go on a single battery charge in one day, the study found. In fact, 87 percent of the vehicles on the road could be replaced by low-cost EVs on the market today even if they were only charged overnight, say the MIT researchers who conducted the study published in Nature Energy.

If this large-scale swap were to happen, it would lead to roughly 30 percent less carbon emissions even—if the electricity were coming from carbon-emitting power plants.

The researchers analyzed daily vehicle travel patterns across the US by bringing together two large datasets. One, the National Household Travel Survey, gave them information on millions of trips made by all kinds of cars. The other included detailed GPS-based data collected by state agencies that measured second-by-second velocity of each kind of trip. The researchers also factored in ambient temperature and inefficient driving behavior to calculate the energy consumption of each trip: extensive heating or cooling and driving habits such as hard acceleration zap energy and can reduce driving range.

Taking the 2013 Nissan Leaf as an example of an affordable EV on the market, the researchers found that it could meet the driving needs of 87 percent of vehicles on a single day. That number could go up to 98 percent as batteries meet new capacity targets set by the Advanced Research Projects Agency-Energy.

What about the remaining 13 percent of trips? The researchers admit that electric cars might not cut it for longer trips, such as vacation travel. For those times, they suggest that people in a two-car household could use their gasoline-powered vehicle, or they could rely on car-sharing or renting services.

The data covered the country’s 12 major metro cities, from dense urban areas such as New York to sprawling cities like Houston. Surprisingly, the adoption potential of electric vehicles was pretty similar across these diverse cities: it only varied from 84–93 percent. “This goes against the view that electric vehicles—at least affordable ones, which have limited range—only really work in dense urban centers,” said the study’s lead author Jessika E. Trancik in a press release.

Trancik and her colleagues admit that addressing range anxiety might not be enough to boost EV sales. “Satisfying consumer preferences for vehicle performance and aesthetics will also be important, as will financing options to offset the purchase price,” they say in the paper. —Prachi Patel | 18 August 2016

Source: Needell ZA et al. Potential for widespread electrification of personal vehicle travel in the United StatesNature Energy. 2016.

Northwest Completes Commercial and Industrial Lighting Strategic Market Plan

Sep 03, 2015

Plan helps shape the region’s energy future by aligning utilities and energy efficiency organizations in the Northwest on a shared, decade-long vision

Northwest energy efficiency experts have developed a Regional Strategic Market Plan that they hope will increase future commercial energy savings by improving cooperation among the region’s program operators.

The Regional Portfolio Advisory Committee (RPAC) of the Northwest Energy Efficiency Alliance (NEEA) unanimously approved the Commercial and Industrial Lighting Strategic Market Plan after strong regional collaboration among its members, state-level representatives and leading lighting experts. Co-chairs Stephen Bicker of Tacoma Power and Fred Gordon of Energy Trust of Oregon provided leadership in developing the regional market plan.

“We are all working in a common space. Planning together at this level not only improves collaboration, it helps us address some shared pain points and simplifies our lives,” stated Stephen Bicker, Senior Conservation Resources Manager of Tacoma Power. “And, taking a longer-term view helps us collaboratively shape the future of efficient lighting.”

Regional Strategic Market Planning is a collective process among Northwest utilities, NEEA and other regional energy efficiency organizations. The purpose is to align the region on longer-term goals in specific markets and maximize cost-effective, long-term energy efficiency opportunities to benefit utility customers.

Market and technology trends are pointing to a changing role for program operators. As energy-efficiency opportunities become more diverse, cooperation is an increasingly important tool to achieve the maximum benefits possible.

“The commercial lighting market is changing rapidly,” said Fred Gordon, Director of Planning and Evaluation at Energy Trust. “The market tends to focus on innovation and profitability, not always energy efficiency. The commercial and industrial lighting plan will guide the region in ensuring utility customers have access to effective and energy-saving lighting options as the market continues to evolve.”

With the regional market plan for commercial and industrial lighting approved, energy efficiency organizations and utilities can better work together to promote awareness and adoption of efficient lighting, open standards for advanced lighting control systems and share useful data to get the maximum benefit for the Northwest.

The next steps for the Commercial and Industrial Lighting Plan include establishing a steering committee to oversee the regional market plan and beginning implementation of specific strategies outlined in the plan.

This regional market plan is the first of four regional strategic market plans slated for development under NEEA’s five-year business plan. Later regional market plans will focus on consumer products, commercial construction and residential construction.

The regional commercial and industrial lighting strategic market plan is available at

About the Northwest Energy Efficiency Alliance

The Northwest Energy Efficiency Alliance (NEEA) is an alliance of more than 140 utilities and energy efficiency organizations working on behalf of more than 13 million energy consumers. NEEA is dedicated to accelerating both electric and gas energy efficiency, leveraging its regional partnerships to advance the adoption of energy-efficient products, services and practices.

Since 1997, NEEA and its partners have saved enough energy to power more than 900,000 homes each year. As the second largest resource in the Northwest, energy efficiency can offset most of our new demand for energy, saving money and keeping the Northwest a healthy and vibrant place to live.