Editor’s note: This article was originally published in May 2015. It has been completely revised and updated to include more comprehensive information, to improve readability and to add current research.
Over and over, I’ve read comments on the internet (obviously, my first mistake) that there is no scientific consensus about GMOs, or genetically modified organisms (generally crops or food), and their safety to humans and the environment.
There are even claims that GMOs are not necessarily productive or provide higher yields, and so called organic foods are healthier (they aren’t) and can lead to higher productivity.
Let’s look at anthropogenic (human-caused) climate change, since it also has this huge controversy over whether there’s a scientific consensus. Over 97% of published articles that expressed a conclusion about anthropogenic climate change endorsed human caused global warming. If that were a vote, it would be a landslide that would make dictators jealous.
According to Skeptical Science, it’s even more than that:
The consensus is so clear, outside of vocal, loud and junk science pushing individuals and organizations, that many scientists call it the “Theory of anthropogenic climate change,” which would mean it’s at the pinnacle of scientific principles, essentially an unassailable fact.
What is a scientific consensus?
A scientific consensus is the collective opinion and judgement of scientists in a particular field of study, based on the quality and quantity of evidence. This consensus implies general agreement, and disagreement is usually limited and generally insignificant.
There is no vote to get this consensus. There is not secret organization that proclaims a consensus.
It’s actually a glacial process from preliminary observations to a point where scientists accept it as the consensus–there’s never really a moment when it becomes a consensus until you’ve passed that point.
It’s generally based on high quality evidence, the best out there. It’s evidence that’s been put through the bright lights of criticism. It’s not done in a backroom of some ancient ivory tower institution, over champagne and caviar.
The first thing you have to know is that a scientific consensus isn’t even close to a consensus you might find in a political meeting or a business team. In the laymen’s use of the term, a consensus is equal to general agreement to move forward. It may or may not arrive because of good evidence, but it’s mostly a method to come to a decision.
Scientific consensus is a lot less formal, and much more reliant upon the quality and quantity of evidence. There is debating about the evidence, but usually through more research, and questioning and answering of new ideas.
The scientific consensus is based on the accrued data, but it has been thoroughly scrutinized by the experts in the field over time. When we talk about the scientific consensus of climate change (or vaccines or GMOs or evolution), these weren’t made by a bunch of journalists or baseball players sitting in that room with food and drinks. It’s made by literally hundreds or thousands of scientists in that field that have many accumulated years of experience and knowledge.
And let me reiterate–this knowledge doesn’t come by hours or days of “research” on Google or reading biased information. If a few thousand geologists, climatologists, and biologists give us a scientific consensus that anthropogenic climate change is real, then that’s solid knowledge.
If you want to dispute this, then you need the accumulated hundreds of thousands of research years of evidence from thousands of real scientists–and then you better be willing to argue your contradicting views in the scientific world, not by being some talking head on Fox News without any real scientific credentials.
Scientific deniers, those who refuse to accept the volume of scientific data without offering the same amount and quality of evidence, are the evil twins of real science.
Now I want to be absolutely clear–the scientific consensus can be overturned. But it’s not a vote, nor is it a debate. It is scientific evidence of equal or better quality and quantity than what established the consensus. And since science is not dogmatic and close-minded, there can be glacial change from one consensus to another. And it’s rare, because arriving at the consensus is based on such huge volumes of evidence, it generally is considered a fact.
The solid GMO scientific consensus
Above, I used the example of climate change as an established scientific consensus. The deniers use all kinds of silly logical fallacies like cherry picking studies that support the denialist opinion, appeal to false authority to show off a denialist scientist, and too many more to mention.
Ironically, there is a huge overlap between climate change supporters (using all of the science in support) and GMO deniers (using all of the science ignorance available to them). To be fair, it is also ironic there’s a small, but significant, overlap between GMO supporters and climate change deniers.
You cannot pick and chose your science to meet your ignorance-based pre-ordained conclusions. It constantly breaks my irony meter. Don’t get me started on vaccine supporters who hate GMOs.
The American Association for the Advancement of Sciences is an international non-profit organization that has as its stated goals to promote cooperation among scientists, to defend scientific freedom, to encourage scientific responsibility, and to support scientific education and science outreach for the betterment of all humanity. It is the world’s largest and most prestigious general scientific society, and is the publisher of the well-known scientific journal Science.
It assembles broad panels of scientists in particular fields of sciences, true experts, to review the scientific data. They then determine if there is a consensus based a little on where the evidence is published (better journals mean better evidence, usually), the quantity of evidence, and how other research is influence by the accumulated data.
Climate change has been investigated for over 40 years, before we eventually got a scientific consensus. GMOs have been around for 10,000 years, give or take, and we have been studying them for several decades too. The consensus for both are so solid, disputing them is borderline denialism, nothing different than someone spouting off that evolution is a lie and the earth is only 6000 years old.
Evidence of solid GMO scientific consensus
There are literally hundreds of scientific articles, most lacking any conflict of interest with those companies who are considered to be a part of the Monsanto shill gambit, that support four important conclusions about GMO crops:
- GMO foods are safe for human consumption. Of course, this is a ridiculous concern since these genes cannot possibly have any effect on humans, since they cannot be incorporated into the human genome, nor can they have any effect on humans. There is no biological plausibility that GMOs have an effect on any biological organism.
- GMO crops are safe for other animals.
- GMO crops increase crop yields and reduce pesticide use.
- And GMO crops are safe for the environment.
As I’ve said many times, there is a hierarchy of scientific evidence from systematic reviews down to junk pushed on the internet. There are many systematic reviews, which takes the best data from all other research and merges it into one giant analysis, which support the safety and yield from GMOs.
- The scientific literature was heavily in favor of the safety, to both the environment and to humans, of GM based agriculture.
- Environmental impact studies are predominant in the body of GM research, making up 68% of the 1,783 studies. These studies investigated environmental impact on the crop-level, farm-level and landscape-level.The researchers found “little to no evidence” that GM crops have a negative environmental impact on their surroundings.
- Little to no evidence that GM agriculture harms native animal species.
A recent systematic review on the impacts of GMOs examined over 147 published articles. This meta-analysis concentrates on the most important GM crops–including herbicide-tolerant soybean, maize, and cotton, as well as insect-resistant maize and cotton. These crops represent a sufficiently large number of original impact studies which have been published to estimate meaningful average effect sizes.
The authors’ meta-review provides the following conclusions:
- GM technology adoption has reduced chemical pesticide use by 37%.
- GM technology increased crop yields by 22%.
- GM technology increased farmer profits by 68%.
- Yield gains and pesticide reductions are larger for insect-resistant crops than for herbicide-tolerant crops. Yield and profit gains are higher in developing countries than in developed countries.
The authors found that:
The solid GMO scientific consensus is nearly the same as the consensus for anthropogenic climate change. Over 89% of scientists who have some expertise in GMOs accept that GMO crops are safe. So those of you who think that science supports one but not the other–well you’d be wrong.
The TL;DR version
- There is scientific consensus regarding anthropogenic climate change is supported by the evidence.
- There is scientific consensus regarding the safety and productivity yields of GMO crops is supported by the evidence.
- The vast majority of scientific experts in the field are part of each consensus.
- If you are a denier about one, but not the other because the science supports one or another, you’re still a denier. But this is about the solid GMO scientific consensus, and it is solid–as solid as the consensus about evolution, climate change, vaccines, or gravity.
- Cook J, Nuccitelli D, Green SA, Richardson M, Winkler B, Painting R, Way R, Jacobs P, Skuce A. Environ. Res. Lett. Quantifying the consensus on anthropogenic global warming in the scientific literature. 2013 January;8(2):024024. doi:10.1088/1748-9326/8/2/024024. Impact factor–4.09
- Klümper W, Qaim M. A meta-analysis of the impacts of genetically modified crops. PLoS One. 2014 Nov 3;9(11):e111629. doi: 10.1371/journal.pone.0111629. eCollection 2014. PubMed PMID: 25365303; PubMed Central PMCID: PMC4218791. Impact factor–3.5
- Nicolia A, Manzo A, Veronesi F, Rosellini D. An overview of the last 10 years of genetically engineered crop safety research (pdf). Crit Rev Biotechnol. 2013 Sep 16. [Epub ahead of print] PubMed PMID: 24041244. Impact factor–5.095.