Good night, night: Light pollution grows
Report says Earth’s artificial light grows by 2% each year.
CAPE CANAVERAL, FLA. — The world’s nights are getting alarmingly brighter
— bad news for all sorts of creatures, humans included.
A German-led team reported Wednesday that light pollution is threaten- ing darkness almost everywhere. Satellite observations during five Octobers show Earth’s artificially lit outdoor area grew by 2 percent a year from 2012 to 2016. So did nighttime brightness.
Light pollution is actually worse than that, according to the researchers. Their measurements coincide with the outdoor switch to ener- gy-efficient and cost-saving light-emitting diodes, or LEDs. Because the imaging sensor on the polar-orbit- ing weather satellite can’t detect the LED-generated color blue, some light is missed.
The observations, for example, indicate stable levels of night light in the United States, Netherlands, Spain and Italy. But light pol- lution is almost certainly on the rise in those coun- tries given this elusive blue light, said Christopher Kyba of the GFZ German Research Center for Geosciences and lead author of the study pub- lished in Science Advances .
Also on the rise is the spread of light into the hinter- lands and overall increased use. The findings shatter the long-held notion that more energy efficient lighting would decrease usage on the global — or at least a national — scale.
“Honestly, I had thought and assumed and hoped that with LEDs we were turning the corner. There’s also a lot more awareness of light pol- lution,” he told reporters by phone from Potsdam. “It is quite disappointing.”
The biological impact from surging artificial light is also significant, according to the researchers.
People’s sleep can be marred, which in turn can affect their health. The migration and reproduc- tion of birds, fish, amphibians, insects and bats can be disrupted. Plants can have abnormally extended grow- ing periods. And forget about seeing stars or the Milky Way, if the trend continues.
About the only places with dramatic declines in night light were in areas of conflict like Syria and Yemen, the researchers found. Australia also reported a notice- able drop, but that’s because wildfires were raging early in the study. Researchers were unable to filter out the bright burning light.
Asia, Africa and South America, for the most part, saw a surge in artificial night lighting.
More and more places are installing outdoor lighting given its low cost and the overall growth in communities’ wealth, the scientists noted. Urban sprawl is also moving towns farther out. The outskirts of major cities in developing nations are brightening quite rapidly, in fact, Kyba said.
Other especially bright hot spots: sprawling greenhouses in the Netherlands and elsewhere.
Photos taken by astronauts aboard the International Space Station also illuminate the growing problem.
Franz Holker of the Leibniz Institute of Freshwater Ecology and Inland Fisheries in Berlin, a co-author, said things are at the critical point.
“Many people are using light at night without really thinking about the cost,” Holker said. Not just the economic cost, “but also the cost that you have to pay from an ecological, environmental perspective.”
Kyba and his colleagues recommend avoiding glaring lamps whenever possible — choosing amber over so-called white LEDs — and using more efficient ways to illuminate places like parking lots or city streets. For example, dim, closelys paced lights tend to provide better visibility than bright lights that are more spread out.