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Robert F Kennedy Jr denies vaccine scientific consensus but accepts climate change

I have long criticized those who deny the vaccine scientific consensus but get angry about those who deny the climate change scientific consensus. In other words, they pick and choose what science they like or don’t like based on random things, mostly political expediency.

Robert F Kennedy Jr (and to save me typing too many letters, we’ll just call him RFK Jr) is a perfect example of this contradictory belief system. If you met him and told him that you deny the overwhelming scientific consensus on human-caused (anthropogenic) climate change, he’d argue that you are wrong. 

RFK Jr said in the past:

All of the modeling for climate change” points to future “storms on steroids, droughts, famine, the disappearance of the ice caps, the disappearance of the glaciers on every continent, and that there’s going to be major disruptions, not just to humanity, but ultimately, to civilization.

That modeling didn’t come from his imagination, it came from scientists, who have established the overwhelming scientific consensus on climate change. It is not based on faith, belief, or Uncle Harry. 

Of course, there is a similar overwhelming scientific consensus regarding vaccine safety and effectiveness, yet RFK Jr and his ilk reject it based on faith, belief, and pseudoscience. It’s clear that RFK Jr picks and chooses whatever science supports his pre-existing beliefs – that’s not science, that’s just illogical thinking.

More than that, how can one trust someone who denies one scientific consensus and accept another? I almost would rethink my position on climate change just because I don’t trust RFK Jr.’s opinion on it. 

But, I’m a good scientist – the scientific consensus on both vaccines and climate change (and hundreds of other scientific ideas like evolution, GMO safety, the Big Bang, etc.) is immense. To quote the esteemed David Gorski, MD Ph.D.:

Hostility towards the concept of scientific consensus is a good sign of pseudoscience.

This article will take a look at how denying the vaccine scientific consensus is equivalent to denying the climate change scientific consensus. Of course, I’m sure that there is a whole bunch of people who deny both, but since this is about RFK Jr., it’s his contradictions that matter.

What is a scientific consensus?

Before we answer that question, let’s remind everyone what the scientific consensus isn’t:

  • It isn’t based on a vote at the Vaccine and Climate Change Scientific Convention (in case anyone doesn’t get sarcasm, there is no such thing).
  • It doesn’t result from a debate among opposing sides of a scientific idea.
  • It isn’t the consequence of a secret cabal of scientists sitting in a dark room, smoking cigars, and drinking expensive wine.
  • It isn’t a “consensus” in a political sense, which is more of a compromise.

A scientific consensus is based on published evidence – that is, if there is substantial evidence that supports an idea, like the vaccine scientific consensus, scientific societies will often publish a statement on that consensus.

There is a process that leads to a scientific consensus:

  • Consilience of Evidence – the vaccine’s scientific evidence is supported by research in diverse fields like epidemiology, public health, microbiology, immunology, virology, and many others. It’s not one piece of evidence that supports this scientific evidence, it’s a large body of robust, repeated clinical and epidemiological studies published in peer-reviewed, high-quality biomedical journals.
  • Social calibration – The experts involved in the consensus agree on standards for evidence –this standard is ridiculously high, which is why it is so powerful. The scientific consensus works both ways – to support scientific knowledge that is evidence-based and reject beliefs that lack similarly powerful evidence.
  • Social Diversity – Having researchers from many cultural and economic backgrounds provides diversity that helps eliminate social biases as a cause of errors. But in general, consensus is formed by the weight of evidence, and to get that weight requires research from nearly everywhere on the planet.

Let me repeat myself – the scientific consensus relies upon evidence, which doesn’t rely upon Google searches, YouTube videos, or bad articles published in predatory journals. It is actually formed by experts, who are substantially more knowledgeable than most of us in particular fields.

As Steven Novella, MD writes in his NeuroLogica blog:

For anyone trying to take a scientific approach to knowledge about the world, we must rely heavily upon experts, or those who are more knowledgable than we are. There is no choice – there is simply too much specialized scientific knowledge for anyone to be an expert in everything, or even a significant portion of scientific disciplines.

Further, being an educated layperson is usually not enough to form your own opinions on specific scientific questions. Forming a reliable opinion often requires a level of detailed knowledge that only an expert in the field can obtain. Even experts can be wrong, of course, and since lay opinions are likely to span all possibilities, some are bound to be correct. Experts, however, are far more likely to have an opinion that accurately reflects the evidence and to understand how to incorporate new evidence as it comes in.

Let’s take vaccines as an example. Understanding just a part of the story of vaccinations requires research into the fields of immunology, virology, epidemiology, infectious diseases, physiology, and possibly dozens of other areas of the biomedical sciences. It is simply impossible for one person to be an expert across all of those fields.

And it’s the same with climate change. The consensus on human-caused climate change isn’t based on one guy screaming at the top of their lungs. It’s based on research from geology to meteorology to dendrochronology (a field of science that studies tree rings, which tell us the story of past weather). 

Back to RFK Jr and vaccine scientific consensus

People like Robert F Kennedy Jr embrace climate change science because it’s almost beyond debate. The science is obvious, and almost all scientific experts in the field state that anthropogenic climate change is a fact. 

Over 97.1% of published papers that had a position on climate change supported the scientific consensus on climate change. That is overwhelming.

And based on that, RFK Jr and I absolutely accept the fact of human-caused climate and stand opposed to climate change deniers who rarely, if ever, have scientific evidence supporting their claims. Going back to his quote above, RFK Jr accepts the science of climate change. Is RFK Jr a climate scientist – no, he isn’t, he’s an attorney with a big name, but he realizes that scientists, far smarter than him, have analyzed climate change and have come to accept the fact that humans are responsible for it.

I am not a climate scientist, and I would not accept Kennedy’s claims about climate change. I would rely upon the academic experts in the field, and the consensus published by respected scientific societies across the world to accept the climate change scientific consensus. I don’t accept this consensus because of trust, but because of the evidence.

Similarly, I don’t accept the vaccine scientific consensus because I believe it to be true (or because Big Pharma sends a truckload of gold bars to me), I accept it because of a similar level of published evidence along with statements from major medical and scientific societies across the world. 

As with climate change, I am not a scientific expert on vaccines. What I am is a scientist (who studied cell biology) who can read and critique published articles, who can understand the statistics (mostly, but I loathe statistics), and who has appropriate credentials in vaccine science.

To me, rejecting the scientific consensus on one but not the other makes absolutely no sense whatsoever.

Vaccine deniers = climate change deniers

What RFK Jr and his sycophants can’t see is that climate change denial is roughly equivalent to vaccine science denial. Both of those groups use the same logical fallacies, the same over-reliance on false authorities, the same cherry-picking of bad science, the same conspiracy theories, and the same love of pseudoscience. 

But I’m guessing that people like RFK Jr don’t notice this.

Let’s take a look at the similarity between those who reject the vaccine scientific consensus and those who reject the climate change consensus.

False authorities

  • Climate change deniers, like Roy Spencer, have published low-quality “scientific research” which has been roundly rejected by real climate scientists. But almost every discussion of climate change requires false balance by including his pseudoscience as if it indicates some sort of debate in real science.
  • Vaccine deniers also utilize false authorities in the vaccine discussion. Ex-scientists like Tetyana Obukhanych and James Lyons-Weiler are marched around by RFK Jr and Del Bigtree as if they’re Nobel Prize-winning scientists. In fact, they have published zero clinical or epidemiological research in a high-quality biomedical journal. Their “science” about vaccines has no quality or merit.


  • There are all kinds of climate change denial conspiracy theories. For example, a few years ago, conservative climate change deniers claimed that there were emails that “proved” that climate scientists were manipulating data. They didn’t. Or that “liberals” are paying for climate change science, because of……..I don’t know. I’m guessing that Big Oil has a lot more money than all environmental groups across the world. 
  • The vaccine scientific consensus deniers want to claim that Big Pharma wants to sell vaccines for profit. In fact, if Big Pharma would want more profits, it would get rid of vaccines, because they’d make much more money from sick children in hospitals. 


Both deniers, of vaccines and climate change, start with a conclusion, then try to find “evidence” that supports the claim. That’s not science.

Real science asks a question, then experiments to answer that question. The data from those experiments are published, then repeated by others, which grows the whole body of that evidence.

Scientists then examine all of that evidence, giving more weight to higher quality evidence, and eventually comes to a “conclusion.” The evidence leads to the conclusion. Pseudoscience has the conclusion in hand before any evidence is published.


Related to pseudoscience is the ridiculous art of cherry-picking data. Both types of deniers love to search for anything that supports their pre-ordained conclusions. And many times, the cherry-pickers don’t actually read the article, and it rarely says what they think it says.

Here’s an example of vaccines – hundreds of clinical and epidemiological studies have established that vaccines are not linked to autism. Vaccine deniers completely ignore that and use another list that relies upon poorly interpreted studies, pre-clinical studies that have little meaning in the hierarchy of clinical research, blog posts, YouTube videos, and anecdotes for “scientific evidence.” In other words, no scientific evidence at all. 

The same in climate change denial. Back to Roy Spencer mentioned previously – despite the fact that hundreds of different climate change models show that humans cause climate change, the deniers will always cherry-pick the ones that support the denialist narrative.


Not that RFK Jr will read this blog post, but why does he think he’s right on climate change (he is) and right on vaccine denial (he isn’t)? The fact that human-caused climate change is real and the fact that vaccines are safe and effective are supported by massive amounts of scientific data. Vaccine deniers and climate change deniers simply lack any credible science supporting their beliefs.

Furthermore, to deny the vaccine scientific consensus but accept the climate change scientific consensus, both of which are scientifically equivalent in the power of research, makes no sense. RFK Jr is not a scientist, but he thinks he can pick and choose what he wants because he thinks he’s an expert. That’s Dunning-Kruger cognitive bias at its best.

That’s just not acceptable. Vaccines prevent diseases that kill children and adults. They are demonstrably safe, probably one of the safest medical procedures today. No, I’m not saying they are absolutely safe, because all medical procedures are a balance between risk and benefit.

But the benefits of vaccines far outweigh the extremely rare risks (some of which are so rare, that it’s difficult to determine if it is any different from the background rate for these “risks”). 

I accept the scientific consensus on climate change because I am a scientist who understands what has built that consensus. RFK Jr probably accepts the climate change consensus because he’s an environmental advocate, but in this case, his pre-ordained conclusion is supported by vast evidence.

I also accept the vaccine scientific consensus also because I am a scientist who understands the foundation of that consensus. RFK Jr denies vaccines because he has that a priori conclusion and rejects all the science because it doesn’t fit his narrative.

I don’t expect scientific deniers to understand their logical problems, because that’s not how they roll. But I hope some of the vaccine deniers who overlap with climate change supporters in the Venn diagram of science realize their logical inconsistencies. To be clear, I hope that doesn’t mean that the vaccine deniers become climate change deniers.

Vaccines are very safe and very effective. That’s settled science.  And human-caused climate change is real. That’s also settled science

Michael Simpson

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