James Lovelock, who turned 100 this year, discusses his life’s work, including his latest theory that AI might be the key to saving the planet. And: former US ambassador Samantha Power on finding ways to make a difference in the face of daunting challenges

This year James Lovelock turned 100. He discusses his extraordinary career with Anushka Asthana, including the invention of a device that detected CFCs, which helped spot the growing hole in the ozone layer, and the Gaia hypothesis, a revolutionary theory that the Earth is a self-regulating super-organism. Initially ridiculed by many scientists as new age nonsense, today that theory forms the basis of almost all climate science.

And: the former US ambassador Samantha Power on finding ways to make a difference in the face of daunting challenges.

Novacene is published by Allen Lane (RRP £14.99). To order a copy go to guardianbookshop.com. Free UK p&p on all online orders over £15. The Education of an Idealist by Samantha Power is published by HarperCollins (RRP £20) . To order a copy go to guardianbookshop.com or call 0330 333 6846.

Archive: BBC