China is increasingly trying to tackle light pollution, a side effect of urbanization with severe consequences for human health and the ecosystem
When a record-breaking heatwave hit the majority of China this past summer, Shanghai finally decided to shut off the lights. The usually glowing metropolis hit the off switch on decorative lights, LED billboards, and light shows along its famous Bund waterfront area on August 22 and 23, to save electricity in the face of hydropower shortages and overloaded grids across the country.
“Currently in Shanghai, the [night] sky in the [city’s central] Xuhui district is 25 times brighter than in Nanhuizui Guanhai Park [in the suburbs],” says Liu Chengze, assistant professor of astronomy at Shanghai Jiaotong University. Back in 2020, Liu and his students found that the brightness of Shanghai’s sky, as measured at the Sheshan branch of the Shanghai Astronomical Observatory (SHAO), had increased 100 times in the past 20 years. This so severely influenced the operations of SHAO’s 1.5-meter optical telescope, once the biggest telescope in East Asia, that it was taken out of operation in 2015, with plans to move it further away from the downtown area in order to better observe the night sky.
But it’s not just an inconvenience to astronomers: Light pollution is tied to major impacts on wildlife, energy waste, and human health risks, in particular circadian rhythms and melatonin production.
Lights Off: China Finally Takes Action on Light Pollution is a story from our issue, “Promised Land.” To read the entire issue, become a subscriber and receive the full magazine. Alternatively, you can purchase the digital version from the App Store.