“There is nothing that an intellectual less likes to change than his mind, or a politician his policy,” says the British writer Theodore Dalrymple.

Mark Lynas is both an intellectual and a political activist—hence his recent decision to change his mind is so notable. Earlier this month, he announced his conversion from foe to enthusiastic supporter of genetically modified crops.

I was in the room when Lynas revealed his change of heart whilst delivering the Frank Parkinson Lecture at this year’s Oxford Farming Conference. His talk deserves a wide audience here in the UK, where we are not allowed to grow the modern crops that farmers in the Americas and elsewhere take for granted.

For years, Lynas has been one of the world’s leading environmental campaigners. He’s best known for his work on climate change. One of his books, “Six Degrees,” won Britain’s most prestigious award for science writing. It was also turned into a documentary for National Geographic, narrated by the actor Alec Baldwin and watched by millions.

When he wasn’t talking about climate, Lynas often could be found protesting GM crops. He was not merely an extremist who wrote newspaper articles against 21st-century agriculture but also a militant who set about damaging GM crop trials.

(See related Road to Damascus change for anti-GM apostle Mark Lynas)

This destructive activity, says Lynas now, “is analogous to burning books in a library before anyone has been able to read them.”

Lynas calls the effort to spread malicious propaganda against GM crops “the most successful campaign I have ever been involved with.”

Now he regrets it.

“I want to start with some apologies,” he said at the beginning of his remarks. “I apologize for having spent several years ripping up GM crops. I am also sorry that I helped to start the anti-GM movement back in the mid-1990s, and that I thereby assisted in demonizing an important technological option which can be used to benefit the environment.”

Instead of yanking GM crops from the soil, says Lynas, true environmentalists should seek to plant more of them.