Artist Kong Ning wears a wedding dress made from respirators to highlight concerns about air quality and pollution in Beijing, China on December 1, 2015. (Photo by Luo Xiaoguang/Xinhua Press/Corbis)

A Chinese man wears a mask to protect against pollution as he waits at a red light while commuting to work in heavy smog on December 8, 2015 in Beijing, China. The Beijing government issued a 'red alert' for the first time since new standards were introduced earlier this year as the city and many parts of northern China were shrouded in heavy pollution. Levels of PM 2.5, considered the most hazardous, crossed 400 units in Beijing, lower than last week, but still nearly 20 times the acceptable standard set by the World Health Organization. The governments of more than 190 countries are meeting in Paris to set targets on reducing carbon emissions in an attempt to forge a new global agreement on climate change. (Photo by Kevin Frayer/Getty Images)

Tourists walk above a tea plantation in Enshi, Hubei province, December 27, 2015. (Photo by Reuters/Stringer)

A folk performer (front R) with make-up and props takes part in a “Blood Shehuo” parade, during a performance in Linyi county, Shanxi province March 21, 2015. “Shehuo” is the common name of Chinese traditional activities consisting of folk performances in northern China. The “Blood Shehuo” performers use make-up and props to re-enact scenes of horror in classic Chinese novels like Water Margin. (Photo by Reuters/Stringer)

A French rock climber named Jean Michel Casanova scales the 172-meter-high steel derrick of the Bailong Elevator, also known as Bailong Sky Ladder, with his bare hands at the Wulingyuan Scenic Area on June 28, 2023 in Zhangjiajie, Hunan Province of China. (Photo by Deng Daoli/VCG via Getty Images)

A woman dressed in Qing dynasty style clothing rides a bicycle along a street near the Forbidden City in Beijing on October 24, 2023. (Photo by Wang Zhao/AFP Photo)

People try to keep warm their hands by a heater as they wait for their seats outside a restaurant at an outdoor shopping mall in Beijing, Saturday, December 23, 2023. A cold wave began earlier in the week bringing extensive snowfall and freezing temperatures across China. (Photo by Andy Wong/AP Photo)

A street cleaner demonstrates his martial arts skills in front of a closed shop near Beijing's Tiananmen Square September 2, 2015 as the capital prepares for tomorrow's parade. (Photo by Damir Sagolj/Reuters)