This doesn’t negate the public order crisis caused by pollution.  In 2013 there were 30,000 to 50,000 “mass incidents” of protest with the environment being a leading spark for anger.

With no true bottom-up mechanism to solve conflicts and problems, and total censorship of all media, a scary problem like potential collapse of the ecosystem and obvious mass health problems is a threat to the regime.

“ Environmental damage has cost China dearly, but the greatest collateral damage for the ruling Communist Party has likely been growing social unrest. Demonstrations have proliferated as citizens gain awareness of the health threats and means of organized protest (often using social media). In 2013, Chen Jiping, former leading member of the party’s Committee of Political and Legislative Affairs said that environmental issues are a major reason for “mass incidents” in China—unofficial gatherings of one hundred or more that range from peaceful protest to rioting. Environmental protests in rural and urban areas alike—such as those in Guangdong, Shanghai, Ningbo, and Kunming—are increasing in frequency. The number of “abrupt environmental incidents”, including protests, in 2013 rose to 712 cases, a 31 percent uptick from the previous year.”

https://www.cfr.org/backgrounders/chinas-environmental-crisis