He used to, with the help of some like-minded friends and the cover of night, destroy them.

Today, this celebrated environmentalist and founding father of the anti-GMO movement says he has changed his mind about genetically modified organisms, and is facing a mountain of backlash because of it.

The British author Mark Lynas, a visiting fellow at Cornell University College of Agriculture and Life Sciences, was in Saskatoon Friday for the Canadian Science Writers Association conference and talked to the StarPhoenix about his about-face on GMOs. While scholarly papers defending GMOs are receiving more press these days, Lynas says the catalyst for his reversal was slightly more lowbrow: an internet troll.

“The moment was probably when I published my last anti-GMO piece in the Guardian newspaper in 2008 and I’d just won the Royal Society Science books prize for Six Degrees: Our future on a hotter planet,” he said. “I was enjoying being celebrated as a trusted scientific authority. And the comments under my anti-GMO article said, ‘This guy doesn’t know what the hell he’s talking about. He’s clearly not familiar with the science on the issue.’ That wounded me. So, I actually learned something from Internet comments. I realized that I had to shut up. Then I had to educate myself and start right back to basics.”

Lynas says when he dug deeper into the practicalities of feeding a world population that is projected to reach 9.6-billion by 2050, the idea of achieving that goal without technology seemed quaint and idealistic, something he blames on the blush of youth. The author says changing his mind has placed him squarely in the role of villain to the anti-GMO faithful.

“I knew at the time I didn’t believe it,” he explained. “I wrote it in an internet café. I thought: ‘God, I really need to have some sources for these things.”

“Obviously I’m demonized in their literature on the Internet. I recognize I’ve got that coming. It’s the penance I have to pay for what I’ve done in the past. I still respect people’s commitment on this issue, even if I think, ultimately, they’re damaging the interests of poorer people and environmental sustainability.”

Lynas’s reversal came early in 2013, in dramatic fashion. At the Oxford Farming Conference, he delivered a 50 minute speech that was met with what he describes as “shocked applause”.

“It was a complete demolition, not just of anti-GMO but of the whole organic thing,” Lynas told the Guardian. “For a lot of people, it was an ‘Oh fuck’ moment. They realised they’d been lied to, at a very profound level, by the very people they’d trusted.”

Lynas said the seeds of doubt about the movement had been planted in him more than a decade earlier.

“Everyone thought of themselves as being tolerant and open-minded,” he says. “But if you said something critical about them, you’d be in quite serious trouble.”

The American astrophysicist Neil de Grasse Tyson, who hosts the radio program turned TV show Star Talk, came face to face with this recently. He suggested that the anti-GMO crowd “chill out” and look at the science. He was met with predictable opposition.

“Practically every food you buy in a store for consumption by humans is genetically modified food,” said deGrasse Tyson. “There are no wild, seedless watermelons. There’s no wild cows…You list all the fruit, and all the vegetables, and ask yourself, is there a wild counterpart to this? If there is, it’s not as large, it’s not as sweet, it’s not as juicy, and it has way more seeds in it. We have systematically genetically modified all the foods, the vegetables and animals that we have eaten ever since we cultivated them. It’s called artificial selection.”

Lynas says that by the time he penned his last piece of what he called “GM Crap” he no longer believed what he was writing.

“I knew at the time I didn’t believe it,” he explained. “I wrote it in an internet café. I thought: ‘God, I really need to have some sources for these things.”

Below: Mark Lynas on his conversion to supporting GMOs – Oxford Lecture on Farming