Energy-saving LEDs boost light pollution worldwide
Energy-saving LEDs boost light pollution worldwide
The study in the journal Science Advances is based on satellite data showing that the Earth’s night is getting brighter, and artificially lit outdoor surfaces grew at a pace of 2.2 percent per year from 2012 to 2016.
Experts say that’s a problem because nighttime lights are known to disrupt our body clocks and raise the risks of cancer, diabetes and depression.
As for animals, these lights can kill — whether by attracting insects or disorienting migrating birds or sea turtles.
The issue isn’t just the LED lights themselves, which are more efficient because they need far less electricity to provide the same amount of light, explained lead author Chris Kyba, a physicist at the German Research Center for Geosciences.
Rather, it’s that people keep installing more and more lights, he told reporters on a conference call to discuss the research.
“We’ll light something that we didn’t light before, like a bicycle path though a park or a section of highway leading outside of town that in the past wasn’t lit,” he said.
“And so all of those new uses of light offset, to some extent, the savings that you had.”
Experts call this the “rebound effect,” and it can be seen with fuel-efficient cars, too. People may buy a car that requires less fuel, then decide to drive it more often or move further from work, lengthening their commute.
The study was based on the first-ever radiometer designed especially for nightlights, called the Visible/Infrared Imager Radiometer Suite (VIIRS).
The VIIRS is mounted on the a National Oceanic and Atmospheric Administration (NOAA) satellite named Suomi NPP, which has been orbiting Earth since October 2011.
Researchers only analyzed nighttime lights during the months of October, to avoid any increase from holiday lights.
“With few exceptions, growth in lighting occurred throughout South America, Africa, and Asia,” said the report.
Declines in lighting were rare, but were noticeable in war-torn places like Syria and Yemen.
Some of the world’s brightest areas, including Italy, Netherlands, Spain and the United States, were all relatively stable.
But even though Milan, for example, made the switch to LED lights and saw a drop in radiance over the 2012-2016 period, there were increases elsewhere in Italy.
“The fact that we did not see the country get darker means that there were new lights in other places, or else brighter lights that were in some other cities installed that make up for this difference,” said Kyba.
Researchers also warned the data was likely an underestimate, because the satellite is unable to pick up the blue wavelengths that are prominent in many LED lights.
“We can say with fairly high confidence even though we didn’t measure in the satellite an increase in these countries, they are nearly certainly increasing in brightness in terms of how human beings would perceive the light,” Kyba said.
One co-author of the study, Franz Holker, an ecologist at the Leibniz Institute for Freshwater Ecology and Fisheries, said the data reveal “quite a critical problem.”
“Many people are using light at night without really thinking about the costs,” he told reporters.
Seeing the big picture from above, he added, “completely changed how I use light at night.”
Excess nighttime light not only harms natural habitats and makes stargazing impossible, it also costs nearly seven billion dollars annually in “negative impacts on wildlife, health, astronomy, and wasted energy,” according to a 2010 study in the journal Ecological Economics.
The latest findings are “not a big surprise to people who have been following this issue,” said Travis Longcore, an assistant professor of architecture, spatial sciences, and biological sciences at the University of Southern California School of Architecture.
Longcore, who was not involved in the study, described the 2.2 percent annual growth rate as “unsustainable.”
The Arizona-based International Dark-Sky Association’s executive director J. Scott Feierabend said the study “validates the message IDA has communicated for years” about the hazards of artificial night lights.
Solutions include using lower intensity lights, turning lights off when people leave an area, and choosing LED lights that are amber instead of blue or violet, since these tend to be the most harmful to animals and humans, experts say.
People also need to question their assumptions, for instance, that nighttime lights make the world safer.
“There is no conclusive evidence that additional light reduces crime,” Longcore told AFP.
“In fact, there is some evidence that shows that additional lights increase crime because criminals can see what they are doing,” he added.
“A lot of things we assume are necessary are just not. They are overkill.”
Ivory Coast looks to solar vehicles to replace bush taxis
- A switch to solar and durables may appear paradoxical in Jacqueville, however, as the area produces the lion’s share of the country’s gas and oil
- Ivory Coast is targeting an 11-percent share of national consumption for renewables by 2020
JACQUEVILLE, Ivory Coast: Hi-tech, cheap — and quiet. The Ivorian resort of Jacqueville just outside Abidjan is betting on solar-powered three-wheelers as it looks to replace traditional but noisy and dirty bush taxis.
“It’s cheaper and relaxing!” says local trader Sandrine Tetelo, of the Chinese-made “Saloni” or “Antara” tricycles, which could eventually spell the end for old-school “woro-woro” four-wheelers as Jacqueville looks to make itself Ivory Coast’s premier eco city.
The mini-cars, 2.7 meters (8.8 feet) long and two meters high, are covered in solar panels each fitted out with six 12-volt batteries, giving the vehicles a range of 140 kilometers (87 miles).
Returning from a visit to China, the solar cars’ promotor Marc Togbe pitched his plan to mayor Joachim Beugre, who was immediately sold.
“We are used to seeing (typically old and beaten up) bush taxis pollute the atmosphere and the environment. We said to ourselves, if we could only replace them by solar trikes,” said Beugre.
“The adventure started in January with two little cars,” added Togbe, who has created a partnership with local businessman Balla Konate.
“I went to China with a friend,” says Konate, “and afterwards I sent four youngsters to Lome for training with a friend who had spoken to me about the project.”
He wants to extend operations to Odienne and Korhogo, towns in the north, the country’s sunniest region.
“Today, a dozen cars are up and running. We are right in the test phase. More and more people are asking for them,” says Beugre, seeing a chance to kill several birds with one solar stone.
Long isolated, his town, nestled between a laguna and the sea, has flourished in terms of real estate and tourism since the 2015 inauguration of a bridge linking Jacqueville to the mainland and cutting transit time to Abidjan to less than an hour.
For the start of the school year in October, Jacqueville plans to bring on stream a 22-seater “solar coach” designed to help deal with “the thorny issue of pupils’ transport.”
Many schoolchildren typically have to travel tens of kilometers from their home village to urban schools.
So far, the trikes have also provided work for around 20 people including drivers and mechanics.
“We’re on the go from six in the morning and finish around 10 or even midnight, weekends too,” says Philippe Aka Koffi, a 24-year-old who has been working as a driver for five months.
“It’s pleasant for doing your shopping more quickly,” says an impressed passenger, Aholia Guy Landry, after riding in a vehicle which can carry four people, driver included.
A big plus is the 100 CFA francs (0.15 euros/$0.18) price of a trip — half a typical downtown “woro-woro” fare — helping to attract between 500 and 1,000 people a day, according to the town hall and promoter.
A switch to solar and durables may appear paradoxical in Jacqueville, however, as the area produces the lion’s share of the country’s gas and oil.
The wells outside the town produce 235 million cubic feet of gas per day, while several foreign firms run pipelines taking oil and gas across the town to feed the refineries at Abidjan.
But the municipality — total budget 140 million CFA francs — sees none of the profits, an issue which has drawn public ire in the past.
The 50-million-CFA trike project is just one piece in a much larger jigsaw which includes the construction of a new eco city on a 240-hectare site among coconut trees.
“It will not be a city for the rich,” insists Beugre, showing off a blueprint replete with cycle paths and a university.
“All social strata who respect the environment will be able to live there,” he adds.
Yet at national level, such plans are conspicuous by their absence.
Ivory Coast, west African leader in electricity production — 75 percent of which comes from thermal energy and the remainder from hydroelectric dams — is targeting an 11-percent share of national consumption for renewables by 2020.
Even though by September the country had burned through barely one single megawatt of solar energy for this year, Beugre is undaunted.
“Our ecological project will go all the way” and “stand up to the power of oil and gas,” says the cowboy-hatted local politician.
“In years to come, we want to ensure that these solar-power machines become the main means of travel in the area.”