Swap to LED Has Upped Light Pollution Worldwide

At What Cost

One of the unexpected and unwelcome effects of switching to LED lighting worldwide is a noticeable surge in light pollution. According to the research published in the Science Advances journal, between the years of 2012 and 2016, light pollution in outdoor spaces grew at a pace of 2.2% each year. The most surprising aspect of this study is that the light pollution change is a product of using LEDs in artificially lit spaces outdoors that were not previously illuminated rather than a simple switchover of established light sources from traditional bulbs to LED.

This stunning growth pattern indicates to scientists that even though LEDs may be energy savers, they are increasingly being used to illuminate places that were not otherwise lit in previous years. And scientists are asking themselves if the tradeoff of more pollution at a lower energy cost is worth it.

The Lighting Revolution’s Effects

Researchers in the US, led by Christopher McKyba, set out to determine the effects of the so-called “lighting revolution” that has come about with the switch to LED bulbs for the sake of decreasing energy consumption. Through the data collected via a calibrated satellite radiometer, scientists were able to observe and measure the light at night as viewed from space.

Not only did the study look at areas that were artificially lit outdoors but it also assessed the total radiance growth over time as well. While the light pollution in outdoor spaces grew, the radiance also increased over the same time period but at only a 1.8% growth rate per year recording a smaller growth rate than the light pollution changes. But the increase in radiance was also significant because this finding led researchers to conclude that the physical locations of lighting increased over time and the brightness of those lights has, too.

This research has helped shine a light on what kind of impact switching over to LED light sources has had on the entire world, something that environmentalists had only speculated about until this groundbreaking research was published.

What Is Light Pollution?

In order to understand how LED lights have led the way in the so-called “lighting revolution,” we first have to define light pollution. According to Live Science, light pollution is “the presence of excess artificial light and is the result of urbanization and industrialization.” Everyone understands that pollution in our water or on the land is detrimental to society but the concept of too much unnatural light is still misunderstood by most people.

We enjoy the benefits of lighting in areas that will help us become safer, like when lighting is applied to a walking path. Not only does the small amount of light increase the usability of the path earlier in the mornings and later into the evenings, but the lit walkway also provides a sense of safety and security all day and night, even if no one is using the pathway.

But the small lights, with the noble purposes of extending the path’s usability and making it safer to use, stay turned on all night long and therefore contribute to increased light pollution. If even one small walkway per neighborhood utilizes these helpful lights, it is easy to imagine what the larger impact would be in a large city alone. For more populated areas, this increase in artificially lit places is directly related to the urbanization and industrialization of that city, state or region.

Where Light Pollution Increased

Anyone out stargazing at night has potentially felt the impact of light pollution since its presence makes seeing the night sky’s beauty more difficult. When an area has more light pollution, the stars are harder to see, and this phenomenon is common in more developed areas. One of the most popular ways that light pollution has increased is from the addition of streetlamps to city and country streets.

With the use of LED lights, this type of lighting has become more affordable as well as checks the energy-saving box for many municipalities. This groundbreaking study about light pollution noted that with few exceptions, the majority of the increases in light pollution came from Africa, Asia and South America. Lead researcher McKyba noted that in these locations specifically, they found that outdoor areas that were previously unlit like park bike paths or roadways that led outside of a town or city were most likely to be the culprits of light pollution since the low-energy usage of LED lights made their installation attractive to the city and local leaders.

By contrast, a few locations did see a reduction in light pollution. Notable in the areas that actually reduced their use of artificial light and resultant pollution is war-torn Syria and Yemen, understandable with the exposure that light can impose on residents during times of conflict. Some of the most lit-up areas, however, can be found in Italy, Spain, the US and the Netherlands. During the years that the study looked at changes in pollution growth and radiance, the brightly lit areas in these four countries were found to be very stable in how much light pollution was observed there.

Finding the Balance: Environment vs Progress

According to this study, the main reason that cities are experiencing a growth in artificial light is that they are able to provide an environmentally friendly way to light up areas that they did not bother to prior to the advent of energy-efficient LED light options. But making progress by providing outside lighting to ostensibly improve the quality of life for citizens has created unforeseen costs that scientists are just now able to calculate.

New Problems Created by Excess Lighting

According to the study published in Science Advances, the negative implications of increases in light pollution are many. Primarily, McKyba’s research indicates that nighttime light will continue to erode health in the land areas that currently experience a natural day-night light cycle in a variety of ways. By introducing unnatural light during a time when it is normally dark, these areas will see multiple avenues in which this light pollution affects not only the people there but also the flora and fauna as well.

Areas that are now lit up to some degree during the nighttime will see nocturnal animals affected by an unnatural day-night cycle interruption. Plants as well as micro-organisms may also be affected by a lack of a natural nighttime cycle and while those effects are not yet known, the researchers speculated that they would also be negatively affected as well.

Humans are also likely to be feeling the negative repercussions of nighttime light pollution. Our sleep cycles are guided by daylight and nighttime darkness, so it is expected that synthetic light at night will impact our body clocks and sleeping patterns. And a lack of healthy sleep is known to be connected to a range of health concerns and problems like depression, high blood pressure and diabetes. While these impacts have yet to be evaluated, this study estimates that these health concerns will be connected in the future if light pollution is not minimized.

Changing Our Habits

While this groundbreaking study is just scratching the surface of understanding how advances in science can benefit us as well as cause a host of unwanted side effects, even the scientists evaluating the findings have noted that the results have impacted their own actions already.

One of the co-authors of this study, Franz Holker, has indicated that he sees the bigger picture now after having participated in this study and seeing how light pollution is affecting the world. Holker states that while “many people are using light at night without really thinking about the costs,” he no longer does. Instead, Holker admits that his night usage of light has completely switched. And the results of this study show us that likely more of us should also be considering how artificial light is impacting the world around us, too.