How an effort to reduce the use of fossil fuels led to another environmental problem: light pollution

In 2014, Los Angeles reduced its annual carbon emissions by 43% and saved $9 million in energy costs by replacing the bulbs in more than half of the city’s streetlights with LEDs.

That year, the Nobel Prize in Physics went to three scientists whose work made these LEDs possible. “As around a quarter of the world’s electricity consumption is used for lighting purposes, LEDs help save the Earth’s resources,” the Nobel committee said. Explain when he announced the price.

For more than a century, most artificial light sources wasted energy in the form of heat. LEDs are much more efficient, requiring less than 25% of the energy consumed by an incandescent lamp. In 2020, LEDs represented 51% of global lighting salesup from just 1% in 2010, according to the International Energy Agency, an intergovernmental organization that analyzes global energy data.

It looks like a clear victory for the environment. But it’s not like that Ruskin Hartley to see him

“The search for efficient luminaires has come at the expense of a rapid increase in light pollution,” he said.

A starry northern landscape behind silhouettes of cedar trees at Cedar Breaks National Monument in Utah.

A starry northern landscape behind silhouettes of cedar trees at Cedar Breaks National Monument in Utah.

(Sumeet Kulkarni/Los Angeles Times)

Hartley would know. He is the executive director of International Dark Sky Association., or IDA, and he’s one of a growing number of people who say the dark sky is an undervalued and undervalued natural resource. Its loss has adverse consequences for wildlife and human health.

And yet, public acceptance of LEDs continues to grow, spilling far too much light into the sky where no one needs it.

“We took a lot of the energy savings and just lit up extra places,” Hartley said. It is a classic example of JevonIt’s a paradoxin which efficiency gains (such as better automobile gas mileage) are offset by increased consumption (people drive more often).

Essentially, say Hartley and others, we have traded one type of pollution for another.

It’s not the only problem. In addition to producing more light, LEDs have changed its fundamental nature.

Compared to incandescent bulbs, LEDs produce a more bluish-white light.

Compared to incandescent bulbs, LEDs produce a more bluish-white light.

(Witthaya Prasongsin/Getty Images)

Light produced by incandescent bulbs had warmer amber or yellow colors, “more in tune with firelight, the only light besides starlight that we know of,” said Robert Meadows, a scientist at the Natural Sounds and Night Sky Division of the National Park Service. LEDs, on the other hand, emit cooler bluish-white tones that exacerbate light pollution for the same reason the sky is blue.

Sunlight contains the full color spectrum and the air molecules are the right size to scatter the shorter blue wavelengths more efficiently than any other. This allows blue light to travel through the atmosphere more easily, giving the daytime sky its familiar color.

After sunset, the same thing happens with LED light spreading unnecessarily across the sky: it diffuses further and increases the “sky glow”, the combined glow of city lights.

The lights of buildings in downtown Los Angeles erase most of the stars from the night sky.

The lights of buildings in downtown Los Angeles erase most of the stars from the night sky.

(Sumeet Kulkarni/Los Angeles Times)

Travis Longcore, an urban ecologist at UCLA, estimates that artificial lighting makes the Los Angeles night sky shine 1.5 times brighter than on a full moonlit night. All creatures are affected by brighter nightscapes, especially those that cannot close the blinds for restful sleep.

“There are many, many species that don’t come out and feed during a full moon because it’s too bright and they know they’re going to be vulnerable to predators,” he said.

According to the National Audubon Society, 80% of North American migratory bird species fly at night and are confused by city lights.

An endangered western snowy plover in Huntington Beach.

An endangered western snowy plover in Huntington Beach.

(Raul Roa/Times Community News)

Even species that stay put are forced to move. A recent study conducted by Longcore found that western snowy ploveran endangered species of shorebird, search for safe roosting sites in the darker areas of Santa Monica Bay when mostly empty parking lots are lit by floodlights all night.

The survival of wild species depends on the variabilities of the natural world – day and night, seasons, lunar cycle. Remove them, Longcore said, and you will inevitably begin to push species away from their natural habitats.

Lightning illuminates the desert floor of Joshua Tree National Park.

Lightning illuminates the desert floor of Joshua Tree National Park.

(Sumeet Kulkarni/Los Angeles Times)

Snakes, for example, are the most active and hunt their prey during new moon nights. The disappearance of the California shiny snake and the Orange County long-nosed snake has been widely attributed to increased ambient light.

Humans are also vulnerable to light pollution. Artificial light blocks the production of melatonin, a hormone that regulates sleep cycles, and disrupted sleep cycles have been linked to a range of health issues. The American Medical Assn. warned in 2016 that high-intensity, blue-rich LED lights were “associated with reduced sleep times, dissatisfaction with sleep quality, excessive sleepiness, impaired daytime functioning, and obesity”.

Longcore calls it “an accident of history” that the first LEDs to be readily available were blue-white in color. LEDs that produce warmer colors with similar levels of efficiency are now available, but the original remains popular with consumers who prefer the way it mimics daylight.

The Milky Way can be seen in exquisite detail in the dark sky above Cedar Breaks National Monument in Utah.

The Milky Way can be seen in exquisite detail in the dark sky above Cedar Breaks National Monument in Utah.

(Sumeet Kulkarni/Los Angeles Times)

Due to sky glow, light pollution is not just a local phenomenon. Even areas located hundreds of kilometers from urban centers cannot escape it.

“You can see Los Angeles from Death Valley at night,” Meadows said.

The reason light pollution keeps getting worse, Hartley said, is that people aren’t even aware it’s a problem.

“I don’t think anyone is intentionally setting out to pollute at night,” he said. But when it comes to lighting our surroundings for safety, “there is an assumption that because a little light is good, more light must be better”.

The one good thing about light pollution is that, unlike pollution caused by chemicals or plastics, it is completely reversible. Merely turn off enough lights and the dark skies will be back in an instant.

“The solution doesn’t mean plunging us into medieval darkness,” Hartley said. This involves thinking carefully about the purpose of each lamp installed, ensuring that its light is limited to the intended space, and only turning it on for as long as necessary.

Mexico, France and Croatia have enacted national light pollution laws. Since 2013, France has required all shops and offices to turn off their lights after 1 a.m.

Nineteen States, the District of Columbia and Puerto Rico have laws in the books to avoid light pollution. Arizona, home to several large telescopes, requires all exterior lights to have shields that prevent light from escaping skyward. Some Florida coastal areas enforce low-power amber lights that do not direct hatchling sea turtles away from the safety of the Gulf of Mexico.

Such laws do not exist in California, but Assemblyman Alex Lee (D-San Jose) introduced a invoice this would require all exterior lights of state government buildings to be shielded and have warmer color tones. They should also be dimmed or turned off at night, although they may turn on if activated by a motion sensor.

The bill has passed both houses of the Legislative Assembly, and it’s now up to the governor. Gavin Newsom to decide whether to sign him or not.

Being limited to state ownership, the bill fails to address the worst culprits of light pollution, including stadium floodlights, industrial lights, outdoor residential lights and streetlights.

Still, Longcore sees it as “a baby’s first step that needs to be taken.” If the government leads by example, more people will recognize the importance of this issue, he said.