In principle, does the manner in which genetic engineering is currently used in agriculture pose a threat to our environment, or provide benefits?

I understand there are concerns about reduction of genetic diversity, but are there more specific concerns? Can such concerns be outweighed by reduced need for pesticides and fertilizers that GMOs promise? Could increased yields reduce impact on the planet by slowing rates of deforestation? Are there models which predict interaction between GMO use, yields, chemical use, etc?

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    We are part of our environment, and our health is part of the health of our environment. Excluding our health from the question is like excluding lions from an ecology study of Africa, where they are an integral part of the ecosystem. Dec 13, 2016 at 0:24
  • @HighlyIrregular, I made the question a bit more open-ended since it hadn't gotten any responses.
    – LShaver
    Dec 20, 2016 at 14:24
  • @Carpetsmoker I'll take a look, but that is from 2003 -- quite a bit has happened since then.
    – LShaver
    Jan 3, 2017 at 19:58
  • Your question first asks whether it poses a threat, then you ask for concerns. Since this is a hot topic, I suggest that you edit your question (again) and limit yourself to one of the two. Personally, I would favor the first phrase, so that we can limit ourselves to facts instead of the endless discussions that we see on so many websites. (Or maybe split into two questions that reference each other)
    – user2451
    Feb 16, 2017 at 11:17

2 Answers 2


Yes, there are many concerns regarding the impact of GMOs on the environment. First, let us understand what a GMO is. This is when someone alters the genetic makeup of an organism by inserting genes into its genome. Thus, compared to more traditional methods of plant breeding, which are more gradual, and limited to species that can breed together, GMOs are much faster and have greater variety. Thus, the difference between a GMO versus a domesticated organism that has been bred is only that a GMO happens suddenly with a wider range of possibilities. I am clarifying this because even more traditionally bred species can have some of the same problems, but are generally lower risk. For example, killer bees are the result of breeding gone awry.

That said, the impact of any GMO is not known until it is released into the environment. Might it become invasive and cause extinctions? Might it be particularly vulnerable to some variable that is unforeseen, causing huge fluctuations in the food supply? We don't know, and nor do we have sufficient understanding of ecosystems and the complex interactions between organisms below and above the ground to possibly create accurate models of how they currently work, much less with a new organism with new genomes in the mix.

There are studies of the impact of specific GMOs on specific variables, such as on a particular pest. For example, a GMO can be designed that would excrete a pesticide on its own leaves rather than needing this pesticide to be sprayed on. Results have shown that this type of pesticide distribution can be more harmful to natural cycles since it has a more extreme effect than standard pesticides do, and cannot be adjusted after it has been produced.

As a side note, GMOs are not designed for extra food production. Traditional breeding is sufficient for this. GMOs are designed to reduce pesticide application, work with other chemical products by the same supplier, and to assert ownership rights over living things. Legally, they are more like a product that is owned by the company producing it. Thus, if a farmer buys GMO seeds, those plants are designed to work with other products from the same company, and to require future purchases by that farmer from the same supplier. If those genes spread via natural reproduction to other farmer's fields, the supplier has sued those farmers for having their product on their field, even though the "product" is a living being which spreads itself. This has actually happened, causing huge fees to neighboring farmers.

To sum up, we don't know the true harm of GMOs to the environment, though we know they present a risk greater than invasive species and traditional breeding. However, there are huge economic and legal impacts of GMOs since these are a new type of "product" that is owned by a private company, yet behaves like a living being, reproducing itself.

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    I'm confused by your remark that GMOs are not designed for extra food production. What do you mean by that? The idea behind GMOs is to improve yields, for example by making them resistant to certain pesticides so competing weeds can be removed quickly, or by making crops more pest or drought-resistant.
    – THelper
    Jan 8, 2017 at 13:21
  • This gets into philosophies on agriculture and the causes of food availability. If you look at the work of Vandana Shiva and others in the food resilience arena, the argument that GMOs increase yields overall falls apart, just as the same claim for the Green Revolution does. GMOs are directly designed not for increased yield, but for pest resistance and chemical weedkiller resistance. The claim is that these resistances will result in increased yields, and studies have confirmed this, just as increased yields resulted in the new plant varieties introduced as part of the Green Revolution. Jan 8, 2017 at 14:21
  • The problem is that the overall resilience of the food production system goes down, with soil fertility decreasing, among other factors. The increasingly risky farming environment leads to social problems (e.g. suicides), declining soil fertility, and increasing dependence on external inputs derived from fossil fuels. This results in a system-wide decreasing yield-to-input ratio despite short-term study results of increased yield. Jan 8, 2017 at 14:23
  • Sorry, in the last sentence of my first comment I should have said "short-term increased yields directly from the new plant varieties introduced as part of the Green Revolution". I can't figure out how to edit that post. Jan 8, 2017 at 14:29

The trouble with organisms generally is that they don't stay put. Consider all the alien invasive species man has introduced - eg in the UK, rabbits, Japanese knotweed, rhododendron etc -each country has its own. It is common to see pockets of oil seed rape on the other side of the road, or further, from the crop field. IF they were pest-resistant and hybridised with non GM plants, this trait could spread, with potentially disastrous effects on pests (...insects, which are part of the food web). There are a lot of IFs, but with something as important as the environment on which we depend, it is wise to adopt the precautionary principal.

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