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Do We Need GMOs?

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Most observers agree that we are facing big obstacles to producing enough food sustainably in coming decades. Issues of distribution and food justice remain paramount, but production must also be adequate, and the huge impact that agriculture has on the environment must be reversed.

It is in this production context that genetic engineering (GE) is often said to be essential. But when we look at the assertions that GMOs will be needed to address these challenges, including from scientists in peer-reviewed articles, we find little substantive support. In other words, these statements are conjecture, not science.

It is important to understand the arguments about the need for GMOs, because they make up the foundation of attempts to convince a wary public that this technology should be welcomed with open arms.

Better alternatives

Arguments for the need for GMOs are usually based on several assumptions. First, that genetic solutions are an important part of the “tool box” to improve production. GE is argued to be better, adequate, or at least needed to supplement other technologies. Second, and critical, is that technologies and methods other than GE are likely to be inadequate.

Genetic improvement has been a major part of agriculture since the beginning. Small farmers have long developed crops suited to their environments by selecting seed from plants that fit their needs. And in countries like the US, about half of the huge productivity increases over the last century came from genetic improvements (the very large majority from breeding, not GE). So it is probably a fair assumption that genetics will also be important for further improvements.

But the argument breaks down when considering the relative efficacy of different approaches to food security. So far, breeding continues to be responsible for the large majority of genetic improvement of crops, not GE. We have shown this in detail in our reports, but any search of the literature for traits from pest resistance to drought tolerance will reveal many important examples of breeding in recent years, while GE has brought forward almost nothing since Bt and glyphosate herbicide resistance.

The lack of important GE contributions to food security so far was well summarized recently by prominent global environmental scientist Jonathan Foley of the University of Minnesota. Foley has never been associated with either “side” of the debates about GE:

“Maybe GMOs can actually do some good, if used wisely. So I try to keep an open mind about them.

“But I am unsure whether GMOs are actually delivering substantially more food to the world. In fact, as far as I can tell, they aren’t. Why? Just consider how GMOs are used: Roughly 10 to 15 percent of the world’s cropland is growing GMOs today, mainly for five crops — feed corn, soybeans, cotton, canola and sugar beets. The vast majority of those crops are not feeding people directly, but rather are being used as animal feed, biofuel feedstock or fiber. Of this list, only canola and sugar beets are mainly “food” crops. Furthermore, the GMO traits currently being used today mainly give plants the ability to fight off insects (the so-called “Bt” trait) or to withstand herbicides (the so-called “Roundup Ready” trait). While reducing losses to insects and weeds is important in maintaining high crop yields, most farmers, especially in the U.S., simply switched one method of insect- and weed-control (e.g., more frequent tillage, a broader mix of herbicides and pesticides) with another. These GMOs haven’t made fundamental changes in plant growth or photosynthesis (that has not yet been done with GMOs in practice); they mainly traded one set of pest- and weed-control systems with another. These “turnkey” solutions for pests and weeds have made big farms more efficient, more profitable, and maybe offered some environmental benefits because of reduced tillage and chemical use. But large, sustained yield improvements have not been a major outcome, except for possibly cotton in India, where pest losses were quite severe and ongoing.

“While future genetically modified crops could add other beneficial plant traits, which might help boost productivity in crucial crops, I think the best answers lie elsewhere.”

No-till (and conservation tillage) corn acreage rose substantially to almost 20 percent from the 1980s until GE crops were introduced in around 1996. Gains since then have been small. Similar results have been seen with cotton, with slightly better results for soybeans. GE made no-till easier, but clearly was not necessary.

No-till (and conservation tillage) corn acreage rose substantially to almost 20 percent from the 1980s until GE crops were introduced in around 1996. Gains since then have been small. Similar results have been seen with cotton, with slightly better results for soybeans. GE made no-till easier, but clearly was not necessary.

[Note that yield increases from Bt cotton in India are probably actually relatively small, as detailed by Washington University anthropologist Glenn Stone, and most of the increases in conservation tillage in the US occurred before GE crops came on the scene in the mid-1990s, so GE is not necessary for con-till (NAS 2010, figures 2-4, p. 65), and its contribution should not be exaggerated.]

Foley’s alternatives of reducing food waste and eating sensible amounts of animal products, low-tech solutions to support smallholders, as well as reducing the amount of food crops (like corn and sugar cane) used for biofuels, are better targets for emphasis.

Past as prelude?

But what about the future? Some have said that breeding, the genetic alternative to GE, is played out—great in the past, but at a dead end now. That argument has no merit. Molecular analyses over the past 10 or 15 years have consistently shown that we have barely scratched the surface of the potential for breeding, as scientists writing in the prestigious science journal Nature have recently attested.

Plateaus in the productivity of some crops in recent decades, often cited as the reason we need GE, do not take into account the neglect of these untapped resources. They do not, for example, recognize that this plateau corresponds to large reductions in public resources for breeding over the same interval.

And breeding has been making its own advances on many fronts, from the recognition of the power of participatory approaches with farmers, to genomic methods. We should not make the mistake of thinking that breeding is static, but recognize that as with other technologies, from TVs to phones, it is advancing. As but one example, GE resistance to papaya ringspot virus has been argued to be the only recourse. But advances in breeding that have improved access to closely related plant species have resulted in progress for developing resistance against several major strains of the virus.

Examples like papaya ringspot virus or citrus greening need to be taken in context. In the big picture of overall global food production and nutrition, they are minor blips. And in most cases, arguments that GE is the only viable option are wrong or premature.

Beyond genetics

The undue focus on GE, and production, also ignores the critical importance and value of non-genetic approaches. Empowering small farmers and women through food sovereignty and agroecology is critical, as I argued in my previous post, and is persuasively analyzed in a new peer-reviewed paper that shows the advantages that small farms, agroecology, and food sovereignty have for biodiversity and poverty reduction, as has the UN Food and Environment Program in a recent report.

For example, if we simply rotated our crops, we would not even need one of the main Bt traits for control of corn rootworm in most regions. And if we really cared about increased yield, crop rotation routinely gives higher yields than monoculture using GE. And agroecological practices can reduce pollution dramatically.

The discussion presented here is not, per se, an argument against GE. But this context is important in the overall evaluation of the role of the technology. It is important to understand that when we pull back the curtain, and look past the flashy props, the arguments about the necessity of GE are revealed to be little more than a faith that new technologies inevitably represent progress.

“Why not keep our options open?”

Genetic engineering will probably make some contributions to production, but these will likely be modest based on what we have seen so far, the challenge of using GE for complex traits like drought tolerance, and the much higher cost of GE compared to breeding.

But possible contributions from GE do not mean it is needed if, as seems likely, other approaches will work. Analysis of the coming constraints on food production (like climate change) and the potential of different approaches to improve food production and distribution are needed before any such declarations can be made with confidence. But for my part, I am with Foley—the best answers lie with solutions other than GE.

Still, even if GE is not likely to be among the important solutions to sustainable food security, doesn’t it make sense to continue to invest in it, to keep our options open?

There is a real risk to food security behind this argument. First, GE has been part of monoculture food production systems that are a big part of the problem, not the solution. Whether or not some applications of the technology may be useful, that will not address or reverse this problem.

And, as I have argued before, there are opportunity costs in pursuing GE. Money invested in GE will not go to cheaper and better solutions. GE should be a much smaller part of the public agriculture research portfolio than other mentioned approaches, which are currently neglected.

But that should happen only if important issues are addressed. Measures that would reassure the public about the technology and assure its safety and equitable use are needed: mandatory labeling, better regulations, protection of non-GMO farmers from contamination, and the assurance that any traits developed with public funds would be open source, rather than fodder for further control by transnational corporations like Monsanto and DuPont, are prerequisites to public support.

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About the author: Doug Gurian-Sherman is a widely-cited expert on biotechnology and sustainable agriculture. He holds a Ph.D. in plant pathology. See Doug's full bio.

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2 Responses

  1. Farmer John says:

    GE corn is grown as part of a crop rotation.

  2. M. Jahi Chappell says:

    Well said, Doug. Thanks, as always, for your balanced and well-researched perspective! (I say this quite apart from your gracious link to our recent paper, which still needs a second reviewer to have been fully peer-reviewed.)