On screen he has battled Nazis, stormtroopers and terrorists to save democracy, freedom or civilisation from clear and present danger. Now Harrison Ford describes his latest role as a real-life fight for the future of this planet.

“What is at stake is the ability of nature to provide services to the human community that we can’t afford to do for ourselves,” said the actor, 68.

He was speaking in the central Japanese city of Nagoya, where he is urging the 193 member countries of the UN’s Convention on Biological Diversity to use their 10-day meeting to protect vast swathes of Earth’s surface.

“Intact ecosystems provide us with fresh water, clean air, help produce healthy soils, are the source of genetic material from which to derive pharmaceuticals and regenerate our food supply.

“These are all the free services of nature,” he said, but they are under threat from environmental degradation and “bold and decisive” action had to be taken now.

“One of our missions is to create a sense of urgency, help people understand that... just because they don’t see it in their own lives, the effects are everywhere.

“Where it registers in everyone’s life is in the economic impact; higher costs of food, depletion of fish stocks etc.

“The urgency can’t be overemphasised... We are at a tipping point.”