"But even in that 10-year period, how dramatic the shift has been. No longer do you have the significant questioning of the science.
"How do we move in the face of resistance? We don't do it alone. We build a movement with us."
When asked how she would talk to a world leader who didn't believe in climate change, she said she would take the person to the Pacific.
"You don't have to know anything about the science ... to have someone from one of the Pacific island nations take you to a place where they used to play as a child on the coast and show you where they used to stand and now where the water rises.
"Then it's a matter of saying, 'You don't have to cede power by acting on climate change. There's nothing to fear about your individual political status. This is about being on the right side of history'."
Ardern said one of the obstacles to enduring change was the three-year political cycle.
She alluded to the Government's proposal for zero carbon legislation, which would require future governments to have targets for carbon emissions.
"This needs to be something we embed in our national psyches ... and it needs to endure beyond us as individuals.
"We have the chance here to transition and future-proof our economies ... it's the only option."
She mentioned the Government's goal to plant one billion trees over 10 years, the $100 million green investment fund, and the $3 billion Provincial Growth Fund as ways to help people working in fossil fuel industries to move into a new economy.
She also mentioned the Government's upcoming wellbeing Budget, saying that a model based only on GDP and "growth for growth's sake" could show a country that is supposedly thriving, even if the environment is degrading and carbon emissions are soaring.
Gore, who said he was a "big fan" of Ardern's when he introduced her to the panel, noted the global uptake of electric vehicles and wind and solar energy.
"The world is in the early stages of a sustainability revolution which has the magnitude of the industrial revolution but at the speed of the digital revolution.
"We can solve this. But we need leadership ... We know we can change, so the remaining question is: will we change?"
Sir David Attenborough, who met with Ardern before the panel, said there was nothing more serious than climate change.
"The maddening thing is we know how to deal with it. We just aren't doing so."
The panel also included Anand Mahindra, chairman of the Mahindra Group, and Akira Sakano, chairwoman of the Zero Waste Academy in Japan.