Asian countries' records in limiting light pollution have varied dramatically over the past five years, new research has revealed. While light pollution in China is below the global average, the increase in light pollution in India from 2012 to 2016 was more than three times the average. Pakistan actually grew darker in that time.
The findings were published in peer-reviewed journal Science Advances on Wednesday. After analyzing satellite data and pictures of the Earth at night, the researchers said the amount of outdoor space lit artificially grew worldwide by an annual average of 2.2 percent from 2012 to 2016.
In India, the lit-up area increased by 7.4 percent and the country got 7.1 percent brighter each year.
Despite massive growth of Chinese cities, the country managed to contain its annual increase in the area lit artificially below 2.1 percent and its brightness below 1.9 percent.
Vietnam fared very badly. Its lit-up area grew annually by 15 percent and its brightness by a blinding 33 percent, according to the research.
Pakistan is the only country in the region where the area lit artificially has decreased, by 3.3 percent each year on average. Pakistan's brightness has come down by 3.9 percent, the study claimed
"It's surprising that China has been able to control light pollution to a large extent. On the other hand, the massive increase in light pollution in India may be related to an extensive electrification drive," Christopher Kyba, one of the lead authors of the study, told CGTN.
The fastest growth in night light is happening in developing regions of Asia, Africa, and South America. On the contrary, illumination in brightly lit countries the U.S., the Netherlands, Spain, and Italy has stabilized.
Australia registered a major slump in illumination, but the researchers pointed out that their data was likely distorted by wildfires in the country.
War-ravaged countries including Yemen and Syria saw a significant reduction in artificial light.
LED lights aggravating light pollution
According to the researchers, widespread adoption of energy-efficient light emitting diode (LEDs) bulbs in cities is seriously adding to the artificial night light. It may appear on the satellite imagery that big cities' brightness has decreased after switching to white LEDs but in reality, their brightness increased.
Cheaper LED bulbs that were supposed to bring down energy consumption in fact led to more lit-up areas, the study said.
"We know that LEDs save energy in specific projects, for example when a city transitions all of its street lighting from sodium lamps to LED," Kyba said. "But when we look at our data at the national and the global level, it indicates that these savings are being offset by either new or brighter lights in other places."
Starry nights lost
A similar piece of research, "The New World Atlas of Artificial Night Sky Brightness," last year revealed that light pollution had blanketed the view of starry skies to the extent that visibility of Milky Way had gone down to zero.
According to the study, areas where the Milky Way was completely obscured include the London to Liverpool/Leeds region in England and regions surrounding Beijing, Hong Kong and Taiwan in China.
These researchers found Singapore to be the most light-polluted country, with the entire population living under skies so bright that they were unable to see the stars at night.
Other studies have revealed the harmful impact of light pollution on pollination and migration of nocturnal birds.
"Urban planners should consider high-quality and glare-free outdoor lighting to reduce light pollution," Kyba urged.