Al Gore's global campaign for climate change won him the Nobel Peace Prize, and the film he made about his campaigning won two Oscars.
A decade on, he is back with his follow-up - An Inconvenient Sequel: Truth to Power.
He's been very busy since we last saw him, with cameras following him everywhere from the melting ice caps of Greenland to the UN Climate Change Conference in Paris, and the typhoon-torn Philippines.
Connecting the global dots is what made his first doco so compelling, and he does much the same here too to lesser effect.
However with plenty of material to work with, it still makes for thought-provoking viewing.
What New Zealand audiences in particular may find a little heavy-handed and even jarring here - I know I did - is how much more front and central Gore is here, painting himself far more heroically, the almost evangelical delivery distracting us from his central message.
But that aside, this film is still an important watch.
I remember how incensed I was, how shocked and galvanised I felt watching Gore 10 years ago, and while there is plenty of that still boiling, his follow-up does lack the sense of urgency and overall impact of that first terrifying film.
But this is not a drill, and this sequel serves to remind us of that again.