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Think of an important environmental issue. Now imagine that there is a large body of scientific research, underpinned by peer-reviewed literature, which has arrived at a broad consensus regarding the relative risks that this issue poses to both the natural ecosystem and human well-being. Standing against this majority scientific position is a stark group of contrarians. They do not have much (if anything) in the way of peer-reviewed science to support their arguments, but instead point to controversial studies by partisan think-tanks and fringe researchers. Further, they invoke a number of conspiracy theories to explain why their position has been marginalised to a scientific minority and yet, ironically, they enjoy significant public support of an almost religious zeal. To be sure, the contrarians certainly aren't adverse to appealing to people's religious sensitivities as way of convincing others of their arguments...

"Yes, OKAY", you're telling yourself, "I know all about climate change scepticism. Get to the point." Except I'm not talking about climate change. I'm talking about genetically modified organisms (GMOs).

Genetically enhanced?

The climate debate and the GMO debate have eerie parallels. Certainly, both are highly polarising issues, which present a myriad of conflicting "facts" to anyone wishing to form an educated opinion on the subject(s). You can spend weeks... months... lost in the dark recesses of the internet trying to disentangle fact from fiction, whole truths from verisimilitude, and legitimate concern from moonbeam conspiracy theory.

When it comes to potentially confusing subjects like these, I believe that we should always make it our first priority to consult the relevant scientific literature. What better way to start addressing a topic than by referring to the qualified experts who have studied these matters in depth, subject to rigorous cross-examination by their peers? This is how we truly weed out the good ideas from bad. In its best form, peer review doesn't appeal to a priori beliefs or care for ideological predispositions. What matters is that you can design and carry out a study (or present a theory) according to accepted scientific standards, in a manner that can be replicated and/or tested by others. The strongest theories survive, while the weak are discarded. Indeed, that's the beauty of peer review; it acts as self-correcting and self-regulating mechanism.

But here's the rub: There is a tremendous inconsistency in the way that people use peer review to approach the respective issues of climate change and GMOs. Since my post here is directed at "environmentalists" as much as anyone else, let me use them as an example.

An environmentalist will happily cite the leading scientific journals, the IPCC and other major scientific bodies in defending his/her position on climate change — presumably that it is i) happening, ii) driven by human activity, and iii) will bring negative consequences in the absence of strong mitigating action. To all this, I say, "rightly so". However, change the subject to genetically engineered crops, and suddenly those rules go out the window. The selfsame environmental organisations that invoke the most respected scientific bodies to confront climate sceptics, all but ignore what these organisations have to say about GMOs. If that sounds like an unsubstantiated generalisation, have a look for yourself: Greenpeace, Friends of the Earth, etc... are all remarkably consistent in their inconsistency. To be honest, it's disappointing to see just how few exceptions there are to this trend. I realise that people tend to seal themselves off to evidence that isn't congenial to their world view, but we owe it to ourselves to face facts. Speaking of which, let's consider some of the common charges laid against genetically engineered food...

1) GMO crops are dangerous to our health
Um, no. Since their formal approval and introduction into the American marketplace in 1996 and elsewhere, GMO products have been consumed by hundreds of millions of people. To date, not a single substantiated case of human illness or harm has been documented. Nada... not one. Consistent with this, numerous scientific articles published in leading medical journals have have upheld the notion that authorised GMO crops are safe for human consumption. Claims to the contrary have been rejected by reputable journals precisely because they fail to live up to scientific scrutiny.[*] And, of course, there's a functional benefit specific to genetically engineered crops that somehow keeps getting overlooked in this debate: They can be made to produce additional vitamins and nutrients, which are otherwise lacking in certain staples, and thus improve human health. (E.g. The so-called "Golden Rice", which has been biofortified with provitamin A and thus helps to ward off a deficiency in this important vitamin. Another example, virtually all insulin used to treat diabetes nowadays is produced using GMO processes.)

2) GMO crops are bad for the environment
Again, the evidence suggests quite the opposite. The introduction of GMO crops has generally enabled farmers to reduce their reliance on pesticides and herbicides, or allowed them to use less harmful chemicals (e.g. glyphosate). Using herbicide-tolerant crops has also meant that farmers have had to rely less on tilling the soil as a means of controlling weeds. "No-till farming" is good for the environment in the sense that it helps to prevent soil erosion and rainwater runoff. This not only reduces the loss of important nutrients in the soil, but also means that water quality is improved since less chemicals ultimately end up in the waterway.

3) GMO crops have reduced yields and they are more expensive
Despite the claims of many anti-GMO campaigners, this too remains an unproven accusation. Indeed, according to some of the most extensive studies on the matter, GMO crops have been shown to have lower production costs relative to conventional methods, as well as higher output and other extra conveniences. More importantly, these benefits have generally outweighed the higher costs of the engineered seeds in places like the United States.

Before concluding, let me attempt to pre-empt criticism of this post with two caveats:

First, I am by no means suggesting that peer review or our leading scientific bodies are infallible. Certainly, there are well understood problems associated with group-think (or even article suppression and qualification masturbation), which may undermine the process. Just as a majority position does not necessarily constitute an unassailable truth, so we should not — to channel Richard Horton — confuse scientific "acceptability" with "validity". However, while peer review is subject to occasional bouts of subversion, it remains far superior to the alternatives. (A blogosphere free for all? No thanks...) Again, I refer to the self-regulating nature of scientific review. Call it the market economist in me, but I find it incredulous that an unsound scientific theory could persist at the expense of a better alternative for very long. In any case, if you chide people for not following the scientific consensus on one topic, it behooves you stick to these same principles on others.

Second, beyond the issues of human and environmental health that I focus on here, there may be other legitimate reasons to oppose the dissemination of GMO crops. I like organic products as much as the next relatively well-to-do Westerner, while I've had my say about animal cruelty before. Further, potential control of food chains by a small number of multinationals through patented crop biotechnology seems to me to be a reasonable concern, deserving the standard anti-trust treatment. I also believe that it's crucial not to collapse the feed-the-world movement into some purely technological debate. As Amartya Sen eloquently argued three decades ago in Poverty and Famines, access to food is much more a complex mix of economics, social and political factors than simply a matter of food production and availability. Indeed, hunger continues to persist in many regions that have bountiful harvests. Agricultural innovation is a wonderful thing (read Norman Borlaug), but technological solutions are not necessarily a panacea for problems of socio-economic origin. Still... These are distinct issues from the scientific aspects that I have discussed above (i.e. human health and environmental safety). If opponents of GM want to preserve their credibility, then they need to separate legitimate concerns from the unsubstantiated, discarding the latter in the absence of credible evidence.

THOUGHT FOR THE DAY: What's good for the goose, is good for the gander. Being concerned about the environment and human health doesn't mean that you can have it both ways, choosing to invoke scientific evidence when and where it is congenial to your position. Those of us who think that climate change is a real issue deserving meaningful action rightly point towards the peer-reviewed science as a first stop for informing our opinions. We would do well to do the same for other contentious issues, such as GMOs.

[*] The most  famous example being the highly-charged Puszstai Affair, in which a controversial study by the eponymous researcher was first published and repudiated by the medical journal, The Lancet. That people may feel (justifiably?) dismayed at Pusztai and his co-author's subsequent treatment by the scientific establishment does not detract from the very real flaws in his study. 
For instance, his strange decision to use a non-commercially available GMO crop to pass negative judgement on GMO crops in general. Just to be clear, he created a potato crop (expressing a protein toxin derived from a toxic plant), which had never been approved for human consumption by any government agency. He then fed this to rats and made an assessment of how much damage it caused to their stomachs (as compared to normal potatoes where the same toxin was independently added). As Sir Robert May sardonically observed: "If you mix cyanide with vermouth in a cocktail and find that it is not good for you, I don't draw sweeping conclusions that you should ban all mixed drinks."

For those looking for references, some suggestions for further reading are under the fold:

  • The (US) National Research Council has released several synthesis reports, based on peer-reviewed studies, regarding the relative risks and benefits of GMOs. The latest of these, Impact of Genetically Engineered Crops on Farm Sustainability in the United States, was published in 2010. Building on previous reports, it finds that the genetically engineered crops have brought "substantial net environmental and economic benefits" to American farmers compared to conventional crops, although it cautions on the potential dangers of overuse of the technology. (In essence, the NRC suggests that each new GMO food eligible for commercial production should be evaluated on a singular basis, while increased weed resistance to herbicides should be continually monitored. For the latter, farmers should also avoid using only glyphosate by occasionally mixing in other herbicides to avoid the repeated exposure to one chemical that induces resistance.) 
  • The (UK) Royal Society's 2009 report, Reaping the benefits: Science and sustainable intensification of global agriculture (PDF), which comes in strong favour of GMO crops. (See, for example, Section 4.2 for a brief summary on the impacts on human health.)
  • Similarly, the (UK) Royal Society of Medicine published an article in 2008, Genetically Modified Plants and Human Health, which asserts: "Foods derived from GM crops have been consumed by hundreds of millions of people across the world for more than 15 years, with no reported ill effects (or legal cases related to human health), despite many of the consumers coming from that most litigious of countries, the USA. There is little documented evidence that GM crops are potentially toxic."
  • The World Health Organisation (WHO) weighs with its Modern food biotechnology, human health and development: an evidence-based study (2007): "GM foods currently available on the international market have undergone risk assessments and are not likely to present risks for human health any more than their conventional counterparts."
  • I could, of course, keep going, but those are good places to start... You can see a partial list of (other) scientific bodies and national academies that have issued statements essentially endorsing GMO technology from a health and environmental perspective hereFor the insatiable, the Centre for Environmental Risk Assessment has a full database of studies pertaining to particular GMOs and their relative safety (as well as nutritional content). Here is the relevant Wikipedia entry. And finally, for what it's worth, GM corporate pariah-in-chief, Monsanto, offers it's side of the story, including the aforementioned Pusztai Affair here. [Note: I don't provide this last link as scientific evidence — though Monsanto certainly does cite scientific studies — but you at least owe the accused the opportunity of testimony.]
  • PS - One last link. After my religious snark at the end of my first paragraph, I feel it's only fair to mention that GMOs have in fact received the official Papal blessing! Well... not quite, but members of Pontifical Academy of Science did issue this 15 page statement in late 2010, which strongly supports the development of GM technology. Money quote: "[N]ew human forms of intervention in the natural world should not be seen as contrary to the natural law that God has given to the Creation". Take heart, my friends. Take heart.