Al Gore believes that Donald Trump will not halt the momentum of the climate movement even if he withdraws the US from the Paris agreement.

Speaking at a press engagement for his new documentary An Inconvenient Sequel: Truth to Power, the former US vice-president and environmental activist said that he was confident Trump would commit to the historic climate change agreement, but that even if he did not, it would still not be enough to reverse the move towards renewable energy in many American cities.

“I don’t know what [Trump’s decision] will be, but I think there’s an excellent chance that he will surprise many by deciding to stay in the Paris agreement,” Gore said.

“But in the first four months of his presidency, we have already learned that he cannot stop the solutions to the climate crisis. Large states like New York, California and many others are moving faster than the commitments made by President Obama during the Paris agreement. Cities are now deciding to go 100% renewable – most recently Atlanta, Georgia.”

However, Gore expressed concern that a withdrawal by the US from the Paris agreement could encourage other nations to do the same.

“The Paris agreement has an historic significance of its own,” he said. “And if the largest economy in the world were to withdraw, it would present a risk that some other countries might use that as an excuse. So it’s important that we stay in.”

Trump is expected to make a decision on whether the US will remain in the agreement after he returns from the G7 summit in Italy next week. At a rally in Pennsylvania last month, Trump described the agreement as “one-sided”, prompting concerns that he would move to withdraw from the deal. Several countries, as well as companies such as Apple, BP and Google, have urged the US to maintain its involvement in the deal.

During the press engagement, Gore encouraged Trump to abandon his campaign promise to bring back jobs in the coal industry, and instead encourage miners to retrain for roles in the solar power industry.

“The prospects of going back to the age of coal are zero,” Gore said. “Donald Trump’s promises to the coal miners cannot be fulfilled as he made them, but he could, if he chose, put them to work in the solar industry.”

He added that solar jobs in the US were growing rapidly and that there were twice as many jobs in solar as in coal already, and that Trump’s populism could backfire on him.

“It’s not unknown in history for politicians to make promises to go back to a bygone era and then adjust their promises when people realise that it really was never a realistic hope. I don’t know if he’ll do that, but the country is going to do that.”

Gore also discussed the election of Emmanuel Macron as president of France, declaring himself optimistic about Macron’s willingness to make climate change “a top priority”.

“I met with President Macron in the days during the Paris conference and was very impressed with him,” Gore said. “And since his election he has appointed Nicolas Hulot as the head of his environmental transition and made the climate crisis a top priority, and announced new policies. I couldn’t be more impressed with what he’s doing and I’m very optimistic about it.”

Gore was critical of the Canadian prime minister, Justin Trudeau, for pushing forward with plans to build further oil pipelines on the Albertan tar sands.

“Justin Trudeau has been a breath of fresh air, although I will add there are many in the environmental movement in Canada who are expressing some concern about the encouragement of the Tar Sands development in Alberta. I like Justin but I will put a little asterisk on that,” he said.

Gore said that, despite the progress made, the threat of climate change remained “far higher than any challenge humanity has ever confronted”.

“The dangers we face from the climate crisis are now more severe than what the scientists predicted. It has gotten worse. But the primary message of the movie is: we now have the solutions available. We can solve this. And we are beginning to implement these solutions. But the main challenge is to summon sufficient political will to implement these solutions and that’s why this movie has the message: it’s time for action.”

An Inconvenient Sequel: Truth to Power is the follow-up to the 2006 documentary An Inconvenient Truth, which followed Gore’s campaign to educate global citizens about the dangers of climate change.

The film won two Oscars at the 2007 Academy Awards, for best documentary and best song. An Inconvenient Sequel will be released in US cinemas on 28 July, Australian cinemas on 24 August and UK cinemas on 25 August.