This August, as the southwestern province of Sichuan struggled with widespread power shortages, Shanghai — which gets a significant percentage of its energy from Sichuanese dams — temporarily powered down the extravagant show that lights up the Lujiazui financial district and the Bund every night. To locals tired of the gaudy lighting, the darkened Huangpu riverbank was a welcome change of pace. It also offered a rare glimpse of a Chinese nightscape unafflicted by city managers’ obsession with illumination.

Urban lighting is typically categorized into two types. Functional lighting primarily fulfills the practical needs of city residents at night, while landscape lighting is deployed in an effort to beautify the city’s nightscape. The current boom in landscape lighting has its origins in the northeastern coastal city of Dalian, which began installing newer and more high-powered lights along streets and in public squares as part of a public safety and tourism initiative in the early 2000s. Other cities soon followed suit, eventually sparking an arms race. Buildings were covered in flashing LED lights, and cities lit up their streets like disco halls.

There was no such thing as lights too bright, too colorful, or too seizure-inducing. Light shows were set up along waterfronts, in central business districts, and even in residential communities. More recently, cities have begun adding elaborate drone performances in the night sky during holidays. All of these shows were backed with grandiose promises of attracting tourists and turning office centers — traditionally dead at night — into vibrant landmarks.

But this explosion of urban lighting has had an incalculable adverse effect on urban landscapes, the ecological balance, astronomical observations, and traffic safety.

Light is an intense stimulus, and light shows often rely on garish, high-intensity, high-saturation, high-contrast lighting. In 2019, longtime lighting expert Hao Luoxi marshalled ample evidence to show how nighttime lighting suppresses melatonin secretion, disrupts sleep and biorhythms, reduces immunity, and even causes emotional problems. Hao’s paper cited a study by Japanese and Chinese scholars on illumination in six commercial areas in Shanghai and Hong Kong, with a total of 888 measurement points. The team found that 47% and 86% of the measured circadian stimulation (CS) values in the two cities, respectively, exceeded the working threshold for acute melatonin suppression.

Excessive lighting harms not only people, but also wildlife. For instance, birds use natural light to navigate at night and can only detect approximate route information. When confronted with artificial light, they struggle to perceive buildings and other obstacles; they might even fly in the opposite direction to avoid lit areas or crash into other flying animals. A leading cause of death for migrating North American birds is colliding into tall buildings, and many of these collisions are related to nighttime lights.

Similar tragedies have occurred in China. In August 2006, hundreds of birds died at a ferry site in Dalian after the installation of 14 overly bright light poles. In a 2009 paper on the ecological effects of nighttime lighting at the Summer Palace in Beijing, researchers found that swifts were particularly sensitive to abnormal external light stimuli at night, and were easily frightened from their nests. Likewise, a 2012 paper found that artificial nighttime lighting can disrupt the Siberian rubythroat’s diurnal biorhythm during migration.

The impact of lighting is not limited to birds. Overillumination can make it harder for female turtles to lay eggs and nest, as well as exacerbate the risks of hatching and lower hatchlings’ odds of survival. It can also cause insects to congregate around the lights until they die of exhaustion, reducing the insect population and affecting the food chain.

There are signs that urban planners are finally seeing the light in darker skies. In its technical report “CIE 234: 2019: A Guide to Urban Lighting Masterplanning,” the International Commission on Illumination (CIE) explicitly included obtrusive light as an important control component in urban lighting planning. In China, there have been calls within the government to rethink and act. At the central level, a 2019 government document called for the “special rectification” of vanity projects or politicized projects, including overblown landscape lighting plans. At the local level, the eastern city of Hangzhou specifically raised the importance of a “dark sky” in its 2013 lighting plan and proposed the establishment of a “nighttime reserve” free from light pollution. Only a month before the lights turned off along the Huangpu riverside, Shanghai revised its environmental protections to add language about preventing light pollution.

Progress has been halting. Hangzhou, for example, has been torn between residents’ desire to cut unnecessary lighting at historic scenic spots like West Lake and the city’s desire to increase its “soft power” through social media-friendly lighting projects.

The question of how to effectively implement lighting regulations will linger as long as urban governments continue to regard nighttime landscape lighting, including gaudy light shows, as beautification rather than pollution. But theatrical light shows should not be the norm in cities, nor should buildings serve as a large screen for tacky ads. Instead of highlighting the personality of various cities, the proliferation of landscape lighting has homogenized every city. Let’s allow our cities to brighten and darken with grace.

Translator: Katherine Tse; editors: Cai Yineng and Kilian O’Donnell; portrait artist: Wang Zhenhao.

(Header image: A view of the Lujiazui financial district, sans light show, Shanghai, August 2022. From Tik Tok user @Shawan.Wang)