This time, the stakes are arguably higher with the US inauguration of Donald Trump, who has dismissed global warming as a fraud invented by the Chinese and nominated climate change skeptic Scott Pruitt to head the Environmental Protection Agency.
Despite worries over the potential environmental damage of a Trump administration, "An Inconvenient Sequel: Truth to Power" has a more hopeful message than its predecessor.
"We are going to prevail. I won't give all the evidence of why I am so confident, but I am. Always remember that the will to act is a renewable resource," the 68-year-old former US vice president said Thursday at the world premiere.
"And for those who have any doubt, just remember there are so many others who are yearning to do the right thing and see the right outcome."
The documentary -- screened at the Sundance Film Festival in Utah -- comes 11 years after "An Inconvenient Truth" re-energized the international environmental movement on its way to winning two Oscars and taking $50 million at the box office.
Since then Gore has trained an army of some 10,000 organizers to spread his environmental gospel, with cameras for "An Inconvenient Sequel: Truth to Power" following his sessions.
