Helena Molin Valdés, head of the Secretariat of the Climate and Clean Air Coalition at the UN Environment Office, said at the Beijing International Forum for Metropolitan Clean Air and Climate Actions held by the Beijing Municipal Ecology and Environment Bureau that Beijing has reached an outstanding result on air quality improvement.

"Facing the crisis brought by COVID-19, all countries and cities need to further strengthen the cooperation to face the challenge of air quality and climate change," she said.

According to the city's environment authority, Beijing's annual average concentration of PM 2.5 has dropped from 89.5 micrograms per cu m in 2013 to 42 micrograms per cu m in 2019, which stands at more than a 50 percent decline.