THERE'S a moment in the climate documentary An Inconvenient Sequel: Truth To Power when former US vice-president Al Gore acknowledges he had a detailed plan for his life but life had a different plan for him.
Asked if he believes in fate, Gore (69), remarks: "I'm recalling the story about Winston Churchill who lost an election when he was a younger man and one of his friends said 'Winston, this you will see is a blessing in disguise' and he said: 'Damn good disguise'.
"I'm under no illusions that there is any position in the world with as much potential for bringing positive change to the world as the position of president and since that didn't turn out for me, I'm grateful to have found ways to try and bring positive change outside of the political system."
After serving in Vietnam, Gore, the son of a senator, became a congressman at 28, then a US senator himself. At the age of 39, he made his first run for president before becoming vice president to Bill Clinton and serving in the role for eight years.
In 2000, the Democrat ran for president again. The controversial election resulted in an unprecedented Supreme Court decision after votes in swing state Florida had to be recounted and his opponent George W Bush was inaugurated as the 43rd president of the United States.
Today he refers to himself as a "recovering politician trying not to relapse" and his sole focus is climate change, a subject close to his heart since he was kid growing up on a farm in Tennessee.
"I was taught to respect the land and my parents' generation was very concerned about soil erosion and that's really the first set of lessons I got," says Gore, who has four children with his wife of 47 years, Tipper.
"When I went to college, I had the privilege of learning from one of the greatest climate scientists in history, Roger Revelle, who was the first person to measure CO2 in the Earth's atmosphere. That was really when the proverbial lightbulb went on for me back in the 1960s. I had just assumed that our society would deal with this challenge but when I went to Congress some years later and started asking 'What are we doing?' I found nothing was being done."
Gore organised the first congressional hearing on the climate crisis and asked Revelle to speak.
"But a 20-minute congressional statement was not the same as a full college course and when I saw that it didn't have the impact I hoped it would, that's when I first began to ask the question 'How can this be communicated effectively and clearly?'" he recalls.
"And that's what led me to the work I do almost full-time."
His tireless campaigning was first depicted in 2006's documentary film An Inconvenient Truth, which earned two Academy Awards and brought the climate crisis into the heart of popular culture.
Shortly after its release, he held his first training for what he dubbed The Climate Reality Leaders Corps at his family home in Tennessee.
The movement has now grown to include more than 10,000 people.
"I get a lot of energy and inspiration from all the activists I've encountered all over the world. They're the real leaders of this climate movement in their communities," says Gore, who received the Nobel Peace Prize in 2007.
In An Inconvenient Sequel, cameras shadow Gore at his global training sessions, on visits to Greenland and Miami where he witnesses first-hand the effect of climate change and in Paris where representatives from more than 190 countries congregated for the Paris Agreement (a treaty within the United Nations Framework Convention on Climate Change) in 2015.
It was a huge success but in June this year, President Donald Trump announced his intention to withdraw the United States from the agreement.
"I did fear that some of the countries would use it as an excuse to withdraw themselves but I was extremely gratified when the reaction to Trump, the next day, was the entire rest of the world redoubled their commitment to the Paris Agreement and in the US, our local and regional authorities and business leaders stepped up very strongly," notes Gore.
He quietly laughs when asked if he feels exasperated at times.
"Well, one of the advantages of doing this for a long time is that it gives you a sense of perspective where setbacks are concerned. There have been a lot of them over the years. And yet, over the long run, the movement has been towards the kind of global consensus that was embodied in Paris, even with Trump's announcement. I think the psychological message is the train has left the station. And the signal sent to investors, to businesses, to industries, to civil society is extraordinarily powerful."
Although Gore believes the world "is clearly in the early stages of a global sustainability revolution that has the magnitude of the industrial revolution but the speed of the digital revolution", he doesn't think the crisis is being solved quickly enough. That said, he remains optimistic for the future.
"I'm fond of the aphorism from the late economist Rudi Dornbusch who said 'Things take longer to happen than you think they will, and then they happen much faster than you thought they could'," says Gore, who highlights we're at a political, social and economic tipping point.
"I grew up in the South in a period when the civil rights movement was gaining momentum and I remember vividly conversations when one of my friends would make some racist remark and another would say, 'Oh shut up man, we don't talk that way anymore' and not to over-emphasise conversations between 12 and 13-year-olds, I think they mirrored millions of conversations. The same is true by the way of gay rights. It crossed a tipping point when enough conversations were won."
Gore turns 70 next March but however hectic his schedule, he thrives on his work.
"I do actually because if you have work that feels like it justifies pouring all your energy into it, it gives you a good feeling that you're doing what you're supposed to do and it gives you energy back in return," he notes.
Reflecting on his career, Gore adds, "I was most often criticised for proposing too much and trying to do too much but I'm pretty comfortable I've done the best I knew to do at each stage."
He's also made friends in Hollywood along the way, notably Leonardo DiCaprio who he first met when the actor and environmentalist was 23.
"I love Leonardo DiCaprio, truly. I think it's wonderful he uses his renown to help advance this cause and I'm extremely proud of his decision to make a commitment to really try to solve this crisis," comments Gore.
Given the life he's led, perhaps the Academy Award winner could depict him on the big screen?
After laughing heartily for a moment, the former politician remarks: "I doubt very seriously that that is a role he would want to play."
:: An Inconvenient Sequel: Truth To Power is in cinemas from tomorrow.
