Few developments in modern agriculture are as controversial as genetically modified crops. Depending on who you ask, they are either an essential tool for feeding a growing population or an unnecessary experiment with our food and ecosystems. The reality is more complicated.
Genetically modified crops can offer genuine advantages. Some can reduce crop losses, protect plants against pests or diseases, and make certain aspects of farming more efficient. But a technology can solve one problem while contributing to another and some of the concerns surrounding GM crops have been documented for more than a decade.
So rather than asking whether GMOs are simply “good” or “bad,” there is a more useful question: Are genetically modified crops really a sustainable solution to the problems they are designed to solve?
What Are GMOs and Why Do We Use Them?
A genetically modified organism, or GMO, is an organism whose genetic material has been altered using genetic engineering. In agriculture, selected genes can be introduced to give a crop a particular characteristic that would not be achieved in the same way through conventional breeding. Among the most common traits are resistance to certain insects, resistance to plant viruses, and tolerance to particular herbicides.
The reasoning behind these modifications is easy to understand. Farmers constantly lose crops to insects, diseases and competition from weeds. If a plant can be made resistant to one of those threats, fewer plants may be lost and farming can become easier or more reliable. The World Health Organization explains both how genetically modified crops are produced and why traits such as insect resistance, virus resistance and herbicide tolerance have been developed. And some of those traits genuinely work.
The Benefits of Genetically Modified Crops
One of the clearest examples is insect-resistant Bt crops. These plants have been engineered to produce a protein from Bacillus thuringiensis that is toxic to certain insect pests. Under particular conditions, this can reduce the amount of insecticide farmers need to apply. Virus-resistant crops can similarly prevent losses by making plants less susceptible to particular plant diseases.
This distinction matters because genetic modification does not automatically increase the maximum amount a plant can produce. In many cases, its benefit is instead protecting more of the potential harvest from being destroyed.
There is also considerable potential for genetic engineering beyond the traits that have historically dominated commercial GM agriculture. Crops could, for example, be modified for different nutritional characteristics or improved resistance to environmental stresses.
Taken alone, these advantages make GM crops sound like an obvious agricultural success. The problem appears when we stop looking only at what happens to an individual crop and start looking at what happens to the agricultural system around it.
When the Benefits Come With a Cost
Herbicide-tolerant crops illustrate this particularly well. These crops are engineered to survive applications of particular herbicides. Farmers can therefore control weeds without killing the crop growing alongside them. It is an efficient solution – at least initially. But evolution does not stop because a farming technique is convenient.
When the same herbicide is repeatedly used across large areas, susceptible weeds are killed while naturally resistant individuals have a greater chance of surviving and reproducing. Over time, this creates selection pressure that can lead to populations of herbicide-resistant weeds. This is not a hypothetical concern that has only recently emerged.
The National Academies of Sciences, Engineering, and Medicine documented the agronomic and environmental effects of genetically engineered crops in its extensive 2016 report, including the development of herbicide resistance and the consequences of relying heavily on particular weed-control systems. That date is significant. By 2016, these effects were already established enough to be examined in a major scientific review covering evidence accumulated since GM crops entered commercial agriculture in the 1990s. And resistant weeds are only part of the wider question.
Intensive weed control can affect the diversity of plants growing within agricultural landscapes, with potential consequences further through the ecosystem. Environmental assessments of GM crops therefore also consider issues such as effects on non-target organisms, loss of biodiversity and the possibility of engineered genes spreading into conventional crops or wild relatives. Again, these are not newly invented objections. The WHO was already identifying these as environmental issues requiring consideration more than a decade ago.
Pesticide use requires similar nuance. It would be misleading to claim that GM crops simply cause more pesticide use: insect-resistant crops can reduce the need for certain insecticides. Herbicide-tolerant cropping systems, however, can create a very different relationship with chemical weed control. And pesticides themselves are not environmentally or biologically irrelevant simply because their use is permitted. The WHO explains why pesticide exposure and residues require safety assessment and regulation, including the potential risks associated with these substances.
The real question, then, is not whether “GMOs use pesticides.” It is whether a particular genetically modified crop encourages an agricultural system that remains effective and sustainable over time.
The Bigger Problem – Agriculture, Patents and Corporate Control
Some of the strongest criticisms of genetically modified crops are actually criticisms of the agricultural system surrounding them. Large-scale monocultures, limited crop diversity and repeated dependence on the same methods of pest or weed control are not problems created exclusively by genetic engineering. Conventional agriculture can suffer from exactly the same issues. But that does not mean GM technology can always be separated neatly from the system in which it is sold and used.
Commercial GM seeds may contain patented traits, turning access to particular crop genetics into intellectual property. When seeds, specific agricultural chemicals and farming systems become closely connected, questions arise about how much control farmers retain over one of agriculture’s most fundamental resources: seed. Even the WHO has acknowledged intellectual-property rights, farmers’ rights and concerns about concentration within seed markets as part of the wider debate surrounding GM crops.
This is important because sustainability is not only about whether a crop survives an insect attack this season. A resilient food system also depends on genetic diversity, farmer choice and agricultural practices that remain effective over generations.
Are GM Foods Actually Dangerous?
This is where criticism of GMOs can easily arise – and where an evidence-based discussion needs an important distinction. There is no good evidence that approved genetically modified foods are inherently dangerous to eat simply because they have been genetically modified.
GM foods entering international markets are subject to safety assessments, and the WHO states that those currently available on the international market have passed such assessments and are not considered likely to present risks to human health. That does not invalidate concerns about genetically modified agriculture. Food safety and environmental sustainability are not the same question.
A crop can be safe for a person to eat while the way it is grown still raises questions about herbicide resistance, biodiversity, agricultural inputs, seed ownership or long-term resilience. Conflating those issues actually weakens legitimate criticism. We do not need to claim that eating GM corn is inherently dangerous in order to question whether every system built around genetically modified crops is environmentally sustainable.
So, Are Genetically Modified Crops Really Beneficial?
They can be. That may seem like an unusual conclusion after discussing their problems, but denying their benefits would make the debate unnecessarily simplistic. Insect-resistant crops can reduce losses and, in some circumstances, reduce insecticide applications. Disease resistance can protect harvests. Genetic engineering may also offer useful tools for addressing future agricultural challenges. But beneficial is not the same as sustainable.
A technology that controls a problem today but contributes to resistance tomorrow cannot be judged only by its immediate success. Nor should the productivity of an individual crop be considered without looking at the agricultural landscape, biodiversity and farming system surrounding it.
Perhaps the most telling part of the GMO debate is how long some of these concerns have already been known. Major institutions were discussing environmental effects, biodiversity, herbicide dependence, resistance and questions surrounding seed ownership more than a decade ago. The 2016 National Academies report was already looking retrospectively at roughly two decades of commercial GM agriculture.
Genetic engineering is ultimately a tool. Like any tool, its value depends on what we use it for and how we use it. The question should therefore not be whether humanity should embrace or reject GMOs as a whole. It should be whether each application actually makes agriculture more resilient, diverse and sustainable in the long term rather than simply making an unsustainable system more efficient for a while.