Mark Lynas used to be the kind of fire-breathing activist who sneaked onto test farms and destroyed genetically modified (GM) crops. Today, he’s one of Britain’s most respected science writers and an influential voice in the battle against climate change—winner of a coveted Royal Society Prize for his 2008 book, Six Degrees. In January, Lynas sent shockwaves through environmental circles by publicly apologizing for his role in launching the anti-GM movement. (GM is also referred to as to GMO, for “genetically modified organisms.”) “The GM debate is over,” he told Oxford University’s annual farming conference. “Three trillion meals eaten and there has never been a single substantiated case of harm.” Video of his speech went viral, and he’s been living with the backlash ever since.

Q: You’ve disavowed a cause you were identified with for decades. How are you feeling about your decision?

A: It’s been traumatic, but it’s also been something of a liberation. I’ve obviously been inconsistent in my life, but so are we all. In my view, it’s better to be inconsistent and half-right, than to be consistently wrong. Even the pope doesn’t claim these days to be infallible, yet that’s what most environmental groups do.

Q: Still, you’ve offended your former allies, a lot of whom are now trying to discredit you. Some say you exaggerated your part in founding the anti-GM movement to start with. What’s that been like on a personal level?

A: My whole social scene has been characterized by my environmentalism. I’m in a situation where I can go to a party and I don’t know who’s currently not speaking to me.

Q: On Twitter, Vandana Shiva, a prominent environmentalist in India, likened your calls for farmers to be able to plant GMOs to saying rapists should have the freedom to rape.

A: That was simply astonishing, and frankly, hurtful to people who have actually suffered the trauma of rape. Look, these attacks on me are obviously done in the interests of damage limitation. It’s sort of an emperor’s-new-clothes thing. I have helped expose the fact most people’s concerns about GM foods are based on mythology. Once you can get past the idea that there’s something inherently dangerous about GM foods, it’s a whole different conversation. We actually can tell whether GM foods are safe. They have been extensively tested hundreds and hundreds of times, using different techniques. Many of the tests were conducted independently. The jury is entirely in on this issue.

Q: Why did you choose this time and place to make your mea culpa?

A: I live in Oxford and I was invited. It wasn’t choreographed or preplanned in any way. I just got some ideas together and was asked to speak in a slot that emphasizes some freedom of thought and is meant to be provocative. It wasn’t as if I had a road-to-Damascus conversion, either. I have been developing these themes for several years, and I think this caught media headlines around the world because people [outside the U.K.] hadn’t heard of me before.

Q: You say this wasn’t an epiphany. Describe the intellectual and moral process that brought you to this point.

A: The process was really about familiarizing myself with the scientific evidence, and in fact, with an evidence-based world view in general. I got to that point by becoming less an environmental activist and more of a science writer through my work on climate change and having written two books on global warming. I’d been involved in countless debates with climate skeptics where I would be saying scientific evidence has to be the gold standard. Well, you don’t have to be a complete genius to figure out that scientific evidence is not with the anti-GM lobby. There is this mischaracterization of science, a sort of circular myth-building, at the heart of the anti-GMO cant.

Q: People are going to ask, though: if you admit you were massaging the truth then, how do we know you’re not massaging it now?

A. What I’ve done is difficult, and it’s why so few political leaders ever admit making a U-turn. They need to build up an aura of invincibility, and people’s belief in other people as leaders depends on this mirage. Fortunately that’s not something I’m interested in. This isn’t about me. It’s about the evidence and the truth.

Q. You argue that opposing GMOs is actually anti-environmental.

A. That was the realization that changed my mind. That recombinant DNA is actually a potentially very powerful technology for designing crop plants that can help humanity tackle our food-supply shortages, and also reduce our environmental footprint. They can help us use less fertilizer, and dramatically reduce pesticide applications. We can reduce our exposure to climate change through drought and heat-tolerant crops. So the potential is enormous.

Q: But even if one accepts that GMOs pose no threat to human health, is it not reasonable to worry about unintended consequences? If you make a crop that can’t be choked off by other plants, what might be the impact on the crop land or ecology of a given area?

A: It’s not reasonable, because all of those concerns would apply to any crop plant developed by humans—whether it’s done by genetic modification or conventional breeding. What’s so natural about mutagenesis, which creates a higher level of mutation of the genome through exposure to gamma radiation or mutagenic chemicals—then selects the mutations that confer a cultivation advantage? Conventional [plant] breeders have no idea what the impact is on the rest of the genome, or what allergens might have been created, because the results are not tested. They go straight into the food supply.

Q: You draw an interesting parallel between the denialism over global warming and denialism as it relates to GMOs. Both causes had been close to your heart. Did you reach a point where you had to choose between the two?

A: My overall effort has been to try to crash out an environmentalist perspective that is fully supported by evidence where there’s a scientific consensus. It’s interesting: the GM denialism seems to come from the left, and is particularly motivated by an anti-corporate world view; the climate-change denialism tends to come from the right and is motivated by suspicion of government.

Q: It strikes me that this is very much a story about the power of ideology—how it can blind people to the facts.

A: I agree, but you have to look at where the ideology is coming from, and why it’s so powerful and self-supporting. To my mind, anti-GM is a backward-looking, reactionary ideology, where you have a mythological, romanticized view of pre-industrialized agriculture being taken as the ideal. GM is seen as the opposite of that because it’s the epitome of technological and human progress in agriculture. So you have this collision of world views, where people who are fixated on doing things the old way simply cannot accept that you can even understand DNA, let alone work with it precisely and intentionally.

Q. The organic movement has staked a lot to anti-GM. Can it survive if the global public embraces GMOs?

A. The organic movement itself should embrace GM. The best applications of it mean that crops can be entirely pest-resistant by working in harmony with nature, which is after all what the organic movement is supposed to want. I don’t see any a priori reason why the organic movement accepts mutagenic crops and not GM crops. Ultimately it comes down to an aesthetic or even spiritual preference. We’re beyond a conversation where you can employ logic and science.

Q: So how do you think the organic movement should respond?

A: It’s a key test for them. Remember that most of what the organic movement has claimed is not true. Their food is not more nutritious. It’s not better for the environment. It’s not safer for human health. So what is left? You’re paying a premium for foods which, as Nina Fedoroff said on my blog, is a massive scam. That’s the recent board chair of the American Association for the Advancement of Science talking.

Q: Maybe it’s just a matter of time before you have a splinter group of organic farmers willing work with GM crops.

A: I don’t know. My father is an organic farmer in north Wales and has been asking the Soil Association, the U.K.’s organic certification body, why he can’t grow a blight-resistant GM potato. It wouldn’t need to be sprayed with fungicide, and he could grow potatoes in wet years and not lose the entire crop. They can’t come up with any logical reason why.

Q: Do you eat organic food?

A: I try to avoid it, but my wife keeps buying it.

Q. Why do you avoid it?

A. Partly through bloody-mindedness. Partly because I object to paying more for something that is worse for the environment. And partly because I was shocked about the food contamination and health impacts—you know, the E.coli outbreak in Germany in 2011. I wouldn’t eat organic bean sprouts without giving them a thorough boiling.

Q. It would be easy for you to become a poster boy for genetically modified agriculture.

A. I’m no one’s poster boy, and I’m very careful about distinguishing myself from any industry lobbies. I don’t even speak on the same panels as industry people. For me this is a much wider struggle to reconcile environmentalism, which has so much good about it, with the reality of scientific evidence.