This file photo taken on Dec. 9, 2009, shows smog down a main street of Linfen, in China's Shanxi province, regarded as one of the cities with the worst air pollution in the world. (PETER PARKS/AFP/Getty Images)

The most popular viral phenomenon on Chinese Internet right now has nothing to do with the color of a dress or a baby weasel riding a woodpecker. It's a 104-minute-long documentary about the environment.

Produced and narrated by Chai Jing, a former investigative reporter for Chinese state television, the film "Under the Dome" is in the style of a TED talk or an activist Al Gore documentary, looking at the grim state of air pollution in China and what can be done to remedy it.

The film takes aim at the lax practices and individual poor habits that lead to smog blanketing China's cities. After being uploaded on the weekend, it has generated hundreds of millions of views and social media posts by Chinese netizens.

Chai says she was motivated to embark on the project when she was pregnant and discovered that her unborn child suffered from an ailment likely related to China's noxious air. "I’d never felt afraid of pollution before, and never wore a mask no matter where," Chai, 39, says in the video, according to the Guardian. "But when you carry a life in you, what she breathes, eats and drinks are all your responsibility, then you feel the fear."

The film generated a huge, emotional response online, including angry comments directed at China's political authorities.

“Support Chai Jing or those like her who stand up like this to speak the truth,” said one commenter on Youku, a Chinese equivalent to YouTube, who was quoted by the New York Times. "In this messed-up country that’s devoid of law, cold-hearted, numb and arrogant, they’re like an eye-grabbing sign that shocks the soul."

Importantly, China's censors have done little to stifle the conversation surrounding the film, and in some sense it has received the government's imprimatur. Chen Jining, the country's new environment minister, praised Chai and the film on Sunday, saying it reflected "growing public concern over environmental protection and threats to human health."

In authoritarian China, issues of environmental policy and reform provide one of the few spaces for an independent civil society to make its concerns known.

It also helps that "Under the Dome" includes a call to action on the part of all Chinese.

“This is how history is made," Chai says toward the end of the film, after she convinces a street vendor to use more environment-friendly equipment. "With thousands of ordinary people one day saying, 'No, I’m not satisfied, I don’t want to wait. I want to stand up and do a little something.'"