The GMO debate is over — again. Last week, the prestigious National Academies of Science, Engineering and Medicine issued what is probably the most far-reaching report ever produced by the scientific community on genetically engineered food and crops. The conclusion was unambiguous: Having examined hundreds of scientific papers written on the subject, sat through hours of live testimony from activists and considered hundreds more comments from the general public, the scientists wrote that they "found no substantiated evidence that foods from GE crops were less safe than foods from non-GE crops."
The National Academies process was both impressively inclusive and explicitly consensual. As noted in the preface to their report, the scientists "took all of the comments" — however ludicrous — "as constructive challenges" and considered them carefully. Thus the expert committee patiently gave yogic flyer-turned-anti-GMO activist Jeffrey Smith a generous 20-minute slot within which to make his customary assertion that genetically engineered foods cause just about every imaginable modern ailment. Greenpeace also offered invited testimony. So did Giles-Eric Seralini, the French professor who suffered the ultimate scientific indignity of having his paper claiming rats fed GMOs suffered tumors retracted in 2013.
Each of their claims was examined in turn. Do GE foods cause cancer? No —patterns of changing cancer incidence over time are "generally similar" between the US, where GMO foods are ubiquitous, and the United Kingdom, where they are virtually unknown. How about kidney disease? US rates have barely budged over a quarter century. Obesity or diabetes? There is "no published evidence to support the hypothesis" of a link between them and GE foods. Celiac disease? "No major difference" between the US and UK again. Allergies? "The committee did not find a relationship between consumption of GE foods and the increase in prevalence of food allergies." Autism? Again, evidence comparing the US and UK "does not support the hypothesis of a link."
In a rational world, everyone previously fearful about the health effects of GMOs would read the report, breathe a huge sigh of relief and start looking for more evidence-based explanations for worrying trends in health issues like diabetes, autism and food allergies. But psychological associations developed over many years are difficult to break. A Pew Center poll in 2015 found only 37 percent of the public thought GE foods were safe, as compared to 88 percent of scientists, a greater gap than on any other issue of scientific controversy, including climate change, evolution and childhood vaccinations. These entrenched attitudes are not about to disappear — especially since they are continually reinforced by a vocal and well-funded anti-GMO lobby.
There is also political path dependence. Vermont's GMO labeling law, scheduled to throw US food manufacturers and retailers into chaos when it comes into force on July 1, is predicated on the explicit assumption that GE foods may be unsafe. "There is a lack of consensus regarding the validity of the research and science surrounding the safety of genetically engineered foods," Vermont's Act states in its preamble. Indeed, such foods "potentially pose risks to health [and] safety. Will Vermont's legislature reconsider its Act now that it stands so clearly on the wrong side of a rock-solid scientific consensus? Of course not.
The National Academies report should make particularly uncomfortable reading for the environmental movement, many of whose leading member groups now exhibit all the hallmarks of full-scale science denialism on the issue. A spokeswoman from Friends of the Earth dismissed the report as "deceptive" before she had even read it. The group's website claims that "numerous studies" show GE foods can pose "serious risks" to human health. Another environmentalist group, Food and Water Watch, issued a pre-publication rebuttal that conspiratorially accused the National Academies of having undisclosed links with Monsanto, before reasserting its view that "there is no consensus, and there remains a very vigorous debate among scientists... about the safety and merits of this technology."
But despite these shrill denials, the truth is that there is no more of a debate on the safety of GE crops than on reality of climate change, the scientific consensus on which all these same green groups aggressively defend. And the irony goes deeper: many of the strategies now being employed to demonize GMOs come straight out of the climate denialist playbook. There's the same promotion of false 'no consensus' statements by groups of self-appointed experts. Why, more than 300 "scientists and legal experts" signed a 'no consensus on GMO safety' statement last year, Greenpeace reminds us. That sounds like a lot, until you compare it with the 30,000 "American scientists" who have supposedly signed a petition claiming that there is "no convincing scientific evidence" linking CO2 with climate change, which Greenpeace (rightly in my view) ignores.
There's also a worrying trend towards the harassment of bona fide scientists. Just as senior Republicans have shamefully targeted climate experts with politically-motivated subpoenas, so an anti-GMO group called US Right to Know has slapped dozens of geneticists and molecular biologists working at public universities with repeated Freedom of Information Act requests demanding access to thousands of their private emails. In some cases, scientists have as a result of subsequent campaigns received death threats, and had their laboratory and home addresses circulated menacingly on social media.
There is still plenty of room for genuine dissent moreover. The National Academies report is zealous in pointing out some of the experienced difficulties and drawbacks of GMOs. The overuse of GE crops has indeed led to the evolution of resistance, both in weeds and insects, it finds. Also, industry domination of the technology might restrict access of small farmers in poorer countries to improved seeds. And mandatory GMO labelling might well be a good way to raise public trust in a more transparent food system.
But these real areas of debate do not include GMO safety. That issue has now been definitively put to bed. So let's be clear once again: the safety debate is over. If you vaccinate your kids and believe that climate change is real, you need to stop being scared of genetically modified foods.
Mark Lynas is a writer and campaigner on climate change and a visiting fellow at the Cornell Alliance for Science