Under the Dome, a self-financed movie about China's environmental meltdown, is an Internet phenomenon that has prompted millions of calls to green hotlines and seen bitter accusations leveled at the filmmaker, as Raymond Zhou reports.

It's noteworthy that the most-watched Chinese documentary did not debut in a cinema or on television. Under the Dome garnered more than 155 million hits in the first 24 hours after it premiered on half a dozen Chinese websites on Feb 28, an audience that movies and TV shows can only dream about. Numerous recommendations on social media turned Under the Dome into the talk of the nation.

Just as it sets a milestone in public communications, the film transcends platforms and genres. It's a 103-minute documentary, which is sometimes broken down into smaller segments for easy digestion; it's one continuous speech and PowerPoint-enabled presentation; and it's billed in Chinese as an investigative report. Whatever it is called, it was obviously inspired by An Inconvenient Truth, Al Gore's 2006 Oscar-winning warning on the worldwide threat of global warming.