I have finally understood that GMOs are not dangerous to humans (or there is no evidence on that case) but I still don't know if GMOs are safe to the environment, because I have read that pesticides harm the land where the crops grow.

Item 8 on this particular list of anti-GMO claims states:

8. GMOs harm the environment.

GM crops and their associated herbicides can harm birds, insects, amphibians, marine ecosystems, and soil organisms. They reduce bio-diversity, pollute water resources, and are unsustainable. For example, GM crops are eliminating habitat for monarch butterflies, whose populations are down 50% in the US. Roundup herbicide has been shown to cause birth defects in amphibians, embryonic deaths and endocrine disruptions, and organ damage in animals even at very low doses. GM canola has been found growing wild in North Dakota and California, threatening to pass on its herbicide tolerant genes on to weeds.

Is there any evidence to support this claim?

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    What do you mean by "dangerous to the environment"? Does it have to kill off a species? Does it have to "contaminate the water supply"? Does it have to harm humans in the vacinity of the field? Does it merely have to create an "unnatural concentration" of a given compound? Which GMO crops/animals are you asking about specifically? Jul 27, 2015 at 21:46
  • @J.A.Streich: the quoted paragraph contains a list of ways in which the environment is allegedly harmed: reducing biodiversity by eliminating habitat, birth defects and other damage in animals due to herbicide use, and finding GMOs in the wild which poses the threat of gene transfer to other species.
    – Saibot
    Jul 28, 2015 at 13:36
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    As far as I can see, only the latter point has to do specifically with GMOs; the first two are effects of monoculture and herbicide use, respectively.
    – Saibot
    Jul 28, 2015 at 13:36
  • @Saibot I don't think that bit wasn't there when they first posted, it was added later. Jul 28, 2015 at 15:17
  • @J.A.Streich: Ah, I see. Actually, since only the last sentence in that paragraph is concerned with GMOs specifically, IMO it's not such a good reference claim for the dangers of GMOs anyway.
    – Saibot
    Jul 28, 2015 at 16:01

1 Answer 1


A new report published in US Department of Agriculture suggested that majority of US corn and soybeans in US are being genetically manipulated to withstand certain chemicals and climate conditions and saying that they could cause a major environmental risk:

Because glyphosate is significantly less toxic and less persistent than traditional herbicides …the net impact of HT crop adoption is an improvement in environmental quality and a reduction in the health risks associated with herbicide use (even if there are slight increases in the total pounds of herbicide applied). However, glyphosate resistance among weed populations in recent years may have induced farmers to raise application rates .Thus, weed resistance may be offsetting some of the economic and environmental advantages of HT crop adoption regarding herbicide use. Moreover, herbicide toxicity may soon be negatively affected (compared to glyphosate) by the introduction (estimated for 2014) of crops tolerant to the herbicides dicamba and 2,4-D.

On the other side, one study said that GMO could be helpful for the environment. It said that crops genetically modified to poison pests can deliver significant environmental benefits:

Broadly speaking, the deployment of Bt crops may favour biocontrol services and enhance economic benefits not only in Bt crop fields but also in the whole agricultural landscape.

Furthermore, there is no scientific consensus regarding the environmental safety of the GMOs:

A report by the British Medical Association concluded that with regard to the long-term effects of GM foods on human health and the environment:

‘many unanswered questions remain’ and that ‘safety concerns cannot, as yet, be dismissed completely on the basis of information currently available’.

The report called for more research, especially on potential impacts on human health and the environment.

Adding also this part: there is no consensus on the environmental risks of GM crops:

As with GM food safety, no scientific consensus exists regarding the environmental risks of GM crops. A review of environmental risk assessment approaches for GM crops identified shortcomings in the procedures used and found ‘no consensus’ globally on the methodologies that should be applied, let alone on standardized testing procedures [37]. Some reviews of the published data on Bt crops have found that they can have adverse effects on non-target and beneficial organisms [38]-[41] - effects that are widely neglected in regulatory assessments and by some scientific commentators. Resistance to Bt toxins has emerged in target pests [42], and problems with secondary (non-target) pests have been noted, for example, in Bt cotton in China [43],[44].

To conclude, no scientific consensus is reached regarding the environmental safety of GMOs, takeaway evidence: http://www.enveurope.com/content/pdf/s12302-014-0034-1.pdf

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    We are getting into murky ground here. Firstly, the British Medical Association is hardly in their area of expertise to be pronouncing on environmental issues. Secondly, how do we define consensus? Is 300 signatories enough to claim no consensus? (See also Evolution and Project Steve.)
    – Oddthinking
    Jul 28, 2015 at 10:31
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    On the other side of the argument, the current scientific consensus regarding GMOs remains unchanged regarding that 'they are safe and do not pose a health risk to humans'-geneticliteracyproject.org/2014/07/08/…. However, a scientific consensus is subject to change if there is sufficient reproducible evidence that may impact it, but none of the studies reviewed listed here geneticliteracyproject.org/2015/01/26/… constitute such evidence. Jul 28, 2015 at 11:27
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    "What this evidence suggests is that there is no reason to question the safety of GMOs per se. While there are a few studies that have come to more cautionary conclusions, the findings of these studies are not confirmed by the vast majority of other studies, and those few studies are heavily criticized by other scientists in the field for all sorts of shortcomings that compromise the reliability of the results."-Alexander J. Stein researchgate.net/post/… Jul 28, 2015 at 11:32
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    These field data sets, representing over 100 billion animals following the introduction of GE crops, did not reveal unfavorable or perturbed trends in livestock health and productivity. No study has revealed any differences in the nutritional profile of animal products derived from GE-fed animals- are normal components of the diet that are digested, there are no detectable or reliably quantifiable traces of GE components in milk, meat, and eggs following consumption of GE feed. animalsciencepublications.org/publications/jas/pdfs/92/10/4255 Jul 28, 2015 at 11:42

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