How 'scientific consensus' ended up with a bad reputation

At Arstechnica, they say:

Fiction author Michael Crichton probably started the backlash against the idea of consensus in science. Crichton was rather notable for doubting the conclusions of climate scientists—he wrote an entire book in which they were the villains—so it’s fair to say he wasn’t thrilled when the field reached a consensus.

Still, it’s worth looking at what he said, if only because it’s so painfully misguided:

‘Let’s be clear: the work of science has nothing whatever to do with consensus.’

In physics, where particles either exist or don’t, five standard deviations are required.

While that makes the standards of evidence sound completely rational, they’re also deeply empirical. Physicists found that signals that were three standard deviations from the expected value came and went all the time, which is why they increased their standard. Biologists haven’t had such problems, but other problems have popped up as new technology enabled them to do tests that covered tens of thousands of genes instead of only a handful. Suddenly, spurious results were cropping up at a staggering pace. For these experiments, biologists agreed to a different standard of evidence.

It’s not like they got together and had a formal vote on it. Instead, there were a few editorials that highlighted the problem, and those pieces started to sway the opinions of not only scientists but journal editors and the people who fund grants. In other words, the field reached a consensus.

Consensus is the business of politics.

Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science consensus is irrelevant. What is relevant is reproducible results.'” As a STEM major, I am somewhat biased toward “strong” evidence side of the argument. However, the more I read literature from other, somewhat-related fields (i.e. psychology, economics and climate science), the more I felt they have little opportunity to repeat experiments, similar to counterparts in traditional hard science fields. Their accepted theories are based on limited historical occurrences and consensus among the scholars.

Given the situation, it’s important to understand what “consensus” really means.

Full story here

h/t to nerdyalien

Here is a consensus case in point: The book Hundert Autoren Gegen Einstein (A Hundred Authors Against Einstein), is a collection of criticisms of Einstein’s theory of relativity. Published in 1931, it contains short essays from 28 authors, and published excerpts from 19 more. The rest of the 100 against Einstein was a list of 53 people who were also opposed to his theory of relativity for various reasons. 100_gegen_einstein

When asked about this book, Einstein retorted with this:

In the case of the ‘Skeptic Science’ claimed ’97 percent’, we have at least three.

Surely that must be enough, unless of course this isn’t about science at all, but about the politics of power, oh, and money.

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Craig Mc

Who else but John Timmer, resident global warming hack.

He does have a loyal following, and dissenters are ridiculed mercilessly. More groupthink than frank discussion,

Consensus that is based on hard evidence is perfectly valid [and necessary]. Good examples are Evolution, Expansion of the Universe, Dark Matter, Fusion generating solar and stellar energy, Plate Tectonics.
Now for each of these there are people that reject the hard evidence for different reasons of their own, none of them scientific.

Necessary for what? To make the models work when they don’t otherwise.
Conversely, what is your opinion of models that work which are not supported by consensus?

That is a very good question. While I respect the opinion of Dr Svalgaard I disagree. I would like to see where in the scientific method consensus is. Where in the flow does that enter? It doesn’t.
The people who disagree with the evidence supporting the fields he mentions (Evolution, Expansion of the Universe, Dark Matter, Fusion generating solar and stellar energy, Plate Tectonics) will have to defend their positions with experimental results that the current theory can’t explain or be reconciled with.
There may be a consensus of what is solid science but there is no consensus in the scientific method (IMHO). Solid science is always open to challenges and it should be. It just gets harder and harder for those rejecting it as time goes by and their data gets corrected or explained.

Science is a human endeavor and as such consensus is important. A different way of saying ‘consensus’ might be ‘generally accepted’. This concept defines what we call ‘knowledge’ [and all knowledge is contingent and may be replaced one day by more precise knowledge]. This is very much part of the scientific method as practiced by actual scientists [e.g. such as myself]. A consensus provides a basis for further work, a ‘paradigm’, if you like, within which coherent work can unfold. Often the paradigm is eventually overturned to be replaced by a new paradigm [which extends the domain of understanding]. Without a consensus to build upon, much work will be disconnected. A good example of the detriment of a lack of consensus is the Sun-Weather-Climate situation where over the centuries thousands of papers argue for hundreds of findings, often contradictory.
From my own work I can mention the consensus that have been reached about the strength of the solar wind magnetic field over the past two centuries, or the emerging consensus that the sunspot number needs revision. These findings being ‘established’ allow other researchers who may not be specialists in those fields to build on the results with some confidence, but always with the usual caveat that knowledge is fleeting.

An example of scientific consensus:
The paper also points out where the still is debate about what happened further back in time. but having reached consensus on the past two hundred years allows us to direct our energy towards where their still are unresolved problems.

Science celebrates its great moments when one person breaks the consensus, never when the consensus is formed.
He first breaks with the consensus, at which time the consensus doubts his sanity.
Science is not about falsification, nor peer review, nor Publish or Perish, nor consensuses, nor consequences. Science is exclusively about the predictive power of models – period.

There is no need for consensus when hard evidence supports a conclusion which has never been falsified.
Consensus as a substitute for the null hypothesis is anti-scientific.
Catastrophic man-made global warming has to be promoted by a false consensus, since it has been repeatedly shown false and its null hypothesis never challenged.

I would phrase it as, “the null hypothesis cannot be rejected”. Thus there is no scientific reason to make policy decisions based on unverified alarming claims.

Yes, that’s better. Thanks.

Leif….consensus is only necessary when the hard evidence isn’t good enough

Thats just cynical (and wrong).

No. Many different theories can explain the same “hard” evidences.

With the caveat that even some of these consensus beliefs may be wrong.

Consensus based on hard evidence is natural and unremarkable. The manufactured, weasel-worded, and over-hyped “consensus” is just propaganda.

Lil Fella from OZ

Consensus on evolution?

Yup. Broad and deep.

Broad, deep and rooted in enormous reams of evidence from multiple disciplines. Testable and repeatable experiments. Classic observations and references to common ancestry predicted before those common ancestors were found.
The consensus about evolution is, in its own way, irrelevant because of the preponderance of data and the fact that evolutionary biologists and paleontologists are not only NOT reluctant to share data and found materials but will positively bore you into the ground with their excitement over their discoveries.
And, I will throw this in for free, if evolution were disproved tomorrow, it would not make Creationism any less false.

What purpose does consensus serve in Science? Either a theory has predictive skill or it does not.
If it does not, if the theory has no skill at prediction, no matter how many people believe in the theory, no matter how grand the consensus, the theory has no value. Worse, the consensus serves as a barrier to alternatives that may well have skill.
Now lets consider the alternative. The theory has predictive skill. What purpose does the consensus serve in this case? It tells us to use the theory blindly, without considering that in some cases the theory is misapplied.
The classic example is the normal distribution. The stock market was assumed to follow the normal distribution, in spite of the large body of evidence that it is a power law distribution. The reason was the large consensus in favor of using the better known normal distribution. After all, it is close enough..
However, as the financial melt-down showed, the market is not a normal distribution. Had investors been aware that the consensus was wrong (and dangerous) they might well have considered that the market is much riskier than a normal distribution would suggest.
Thus, the consensus opinion in science does much more harm than good.

Mike Wryley

Good points,
“Generally accepted” can mean one thing, but “consensus” crosses a threshold, perhaps the first tiny step towards groupthink for the lazy thinker. Anyone perspicacious individual over the age of 50 realizes that not only have they seen “consensus” go up in smoke on numerous occasions, but also the human condition is ripe for self delusion. My motto is I don’t believe any thing unless I see it first hand and even then I’m not too sure.

It’s neither required and was slow to develop for most of your examples.

Evolution? Dark Matter? Sorry mate but there is no science in either of those 2 topics.

I see that you are one of those that choose to ignore evidence…

I’m with Leif on this one. There is an embarrassment of experimental evidence and observations in favour of an old Earth, and of the evolution of life from primitive to complex.
It doesn’t require prior belief in evolution in order to accept the evidence (unlike AGW for example), but it does require willingness to let go of religiously inspired, deeply unoriginal creation myths straight of the Bronze Age.

What evidence Lief? There has not been one verifiable eyewitness account to evolution. As more biologists study DNA more are coming to the conclusion that there is a master creator. DNA is a computer code and for each new species there must be a recompile. Evolution just doesn’t cut it. But of course you can be part of the false consensus.
Dark Matter is a mathematical concept to try and balance the books on a subject which is theoretically dead as a doornail. Again not a single observation of this so called ‘dark matter’. No matter Leif, the number of learning centers are taking up the electric universe and you will just become another relic that passes away.

some people are just beyond hope and reach. you seem to be one of them.

Me shrugs shoulders and says “whatever”.

Joseph Murphy

In those cases the consensus is irrelevant. The evidence speaks for itself. To what end is the consensus necessary that is not achieved with a presentation of the evidence?

Ive never heard evidence “speak”. It is necessary precisely because humans are required to interpret the data and we (thank god) haven’t appointed one all powerful science dude to do it for us. We all have unique perspectives and we don’t always agree. It isn’t uncommon for two experts to look at the same evidence and come to opposite conclusions. That is why the 97% consensus on climate change is so remarkable. (very rare and hard to achieve, given out grouchy and independent scientists are)

There are 100 strangers at a cocktail party and one of them is an EXPERT. How do you know who that one EXPERT is? Wait for it……..He’ll tell everyone, of course!

Joseph Murphy

John, I am going to take your response seriously although I am not sure if it is sarcastic or not. First, there is not a consensus on much in climate science. If there were the studies that are touting that 97% line would not be such obvious hack jobs. It is PR propaganda from Doran to Cook. While Leif is defending consensus in science from an acute perspective, one that is not lost on me, it is important to take in a full perspective. What are the benefits of relying on a consensus in science? What are the negatives? Can those benefits be achieved another way? In my view consensus brings nothing to the table that can not be achieved in other ways. And furthermore, relying on consensus as a pseudo form of authority has inherrent risks that mankind does not seem capable of overcoming. Climate science case in point.

Leif, I noticed that climate change was not on your list. Why?
That is in essence the topic, no?
Your point, from your post, would be what exactly?
Regards, Ed

The point is that consensus is good when based on hard evidence

Is that the point when things become fact, not consensus?

A Theory can be “hard evidence”?

yet when wegner proposed his theory, he was derided because the consensus at the time held that tectonic plates didnt move…

Precisely the point. It is experimental evidence, (in this case observations of geological continuities if South America and Africa were really joined together in the remote past).
In point of fact Wegener was derided for his theory of continental drift, and even a conference called which had geologists after geologist present papers on how wrong Wegener was.
Now there’s an Alfred Wegener Institute out there, and the geologists who attacked him are mostly forgotten,

But let us not forget that the consensus was right: the continents do NOT drift and plow through the ocean floor. The seafloor is drifting taking the continents with them.

I’d also add that plate tectonics was unknown when Wegener proposed his theory. His theory proposed that continents float like icebergs on the ocean. That would have lead to landforms not discovered.
In a sense, Wegener’s insight was before its time. But it didn’t stop his basic proposal from being proven correct (and even measurable with modern satellite instruments)

exactly. Thanks Leif.

David A

The consensus was not right as Leif stated. The consensus disputed the basic idea which was correct. Wegner did not get the process exact, but the continental plates do drift on the mantel.

No continental plates. Seafloor plates. That is where Wegner [and you] got it wrong. Continents don’t drift. They may break up into pieces which are carried away by the spreading seafloor.

Leonard Weinstein

The difference between seafloor and continents is that the seafloor is covered with water and has thinner crust. However, they are both parts of solid surface segments which spread apart in some locations, both in oceans (e.g., mid Atlantic) and on land (e.g., iceland), and they subduct at some borders, mostly in the oceans (e.g., Pacific trenches) due to being thinner there. The combination of extruding and subduction drives differential plate movement, including edge to edge slippage and net displacement movement of the continents, and changes in sea shape. The movement causes earthquakes and volcanoes.

David A
Ian Schumacher

Consensus is fine. It’s the “bait and switch” that is dishonest i.g. get a consensus on “Earth has warmed and man is probably partly responsible” and then pretend you have a consensus that “Mankind is in serious danger and extreme and drastic measures must be immediately taken”.
And of course we would always do well to take any consensus with a grain of salt. The number of times ‘everyone’ agreed on something only to be shown to be incorrect later on are too numerous to count.

Ed Barbar

Plate Tectonics was rejected by the consensus. Consensus is reached because it explains more than the alternatives in a better way.
Religion is scientific: it explained things. It evolved to better explanations, from many gods to singular gods. Science evolved from religion to explain things even better. Then, there was this new thing, which is things that are so expansive that can not be proven, like string theory and climate science. These are devolutions, and not much better than the original gods, in my estimation.

Pat Frank

Actually, it seems to me that “many gods,” some of which don’t like others and all of which are limited and fallible, is a better explanation for the chaos on Earth and the indifferently callous fates of people, than supposing a single all-everything god which is necessarily an ethical monster.

IMO, A post like Mr Barber’s is best ignored. Life is too short to reply to those. Even one liners.

Pat Frank

couldn’t help myself, Joel. 🙂

Pat Frank

My hard copy of Merriam Webster’s Collegiate (I’ll check my M-W unabridged tonight):
1: group solidarity in sentiment or belief.
2a: general agreement: unanimity
2b: collective opinion
It seems pretty clear to me that “consensus” in AGW is of the first kind in fact, and misrepresented as of the second kind by protagonists.
Go ahead and use the word as you like, Leif, but “consensus” is ambiguous in meaning and any desire for clear communication requires specifying what you mean by it. 1a : general agreement
In science it clearly means that as science is not a negotiated arena. If you use it in any other meaning about a scientific subject, it is you that are misusing the concept. This should be clear enough.

Pat Frank

“Consensus” in the case of hard evidence is the wrong word, Leif. The correct expression is widespread acknowledgement.
Consensus typically means a general agreement following some negotiated settlement. Consensus has the sense of a treaty. Science doesn’t work by negotiated settlement, and agreed views in science do not reflect treaty negotiations.
Widespread agreement means that scientists have individually made up their minds, and have come to a spontaneous general agreement about meaning without any necessary interpersonal negotiation at all. There may have been debate, and in most cases there certainly was some.
But debate does not include negotiation, although negotiation may include some debate. The two processes are sort of non-Hermetian.
In Chemistry, the debate among Herbert Brown, Saul Winstein, and George Olah about the existence of non-classical ions in certain organic molecules is an excellent example of how agreement emerges among scientists.
The debate raged for years, and involved more and more exacting experimental studies. When it was over, there was a general agreement on the meaning of the data and the specific conclusion they warranted.
The agreement wasn’t negotiated and it isn’t a consensus in that sense.
Agreement among scientists is an emergent self-organized phenomenon that arises from individual choices about meaning. The fact that, at the end it looks like a consensus to an external observer, in that many people subscribe to a certain idea, does not mean it is a consensus in fact. Process is critical to the distinction.

Ian Schumacher

Good point. Science isn’t about consensus, but there is a large degree of ‘collective consciousness’ and the resulting coincidental agreement, (which still often ends up being wrong).

The simple dictionary definition of ‘consensus’ is ‘general agreement’. Nothing about a negotiated agreement.

You could say that there was a negotiation of sorts in the years it took to collect and interpret the data and then have people generally accept the results. When you persuade a scientific colleague (or rival) of an interpretation that is still consistent with their view, you have a consensus. It may be a bit different from a political consensus – that is true.
The real problem is arguing that because a consensus exists, that it means that it is a fact. It is a logical fallacy but often may be true. The fact that most scientists accept general relativity could be persuasive. But it does not mean people are not allowed to try to rebut it.
The second problem w.r.t. climate science is (as others have often pointed out) is that what 97% of climate scientists agree to is much less extreme than how it is portrayed.

Pat Frank

Leif, the first definition for consensus in my Merriam Webster’s is, “group solidarity in sentiment and belief.” That definitely implies a group-negotiated agreement, with a good dollop of irrational adherence.
Bill_W, agreed there is a large penumbra of meaning around ‘negotiation,’ ‘consensus’ and so forth. But when the topic is important, it becomes necessary to be sure that everyone applies the same meaning to the centrally descriptive words. I just wanted to distinguish the way scientists come to their agreements (emergent) from the way politicians do (negotiation). The AGW “consensus” (if there really is one) is definitely of the latter.
1 a : general agreement : unanimity
b : the judgment arrived at by most of those concerned
2: group solidarity in sentiment and belief

Pat Frank

Sorry for the delayed response.
From Merriam-Webster’s Unabridged Dictionary (Third New International)
1a: Harmony, cooperation, or sympathy, esp. in different parts of an organism.
1b: group solidarity in sentiment and belief.
2a: general agreement.
2b: collective opinion: the judgment arrived at by most of those concerned.
3: a formal statement of religious belief.
Very little there, Leif, showing that critical evaluation of data is a necessary part of consensus.

Well, if you want to cherry pick your source, I can cherry pick mine: The first meaning is ‘general agreement’.
And in science the General Agreement comes about because of the presence of hard and good data. That is what drives scientists individually to general agreement, not as part of a group.

Pat Frank

Merriam-Webster’s Unabridged is hardly cherry-picking Leif. It’s the dictionary ubiquitously presented in public libraries as the definitive source of American English usage.
For more cherry-picking, here’s Oxford English:
1: General agreement or concord of different parts or organs of the body in effecting a given purpose; sympathy. Hence transf. of the members or parts of any system of things.
2a: Agreement in opinion; the collective unanimous opinion of a number of persons.
2b: Also consensus of opinion, consensus of authority, consensus of testimony, etc.
That all said, I fully agree with your comment that, “In science the General Agreement comes about because of the presence of hard and good data. That is what drives scientists individually to general agreement, not as part of a group,” which is pretty much my original point.

Yet on their web-site the have general agreement first. So, you are saying that their website does not reflect their current definition. One would think that the print edition would always lag the web version, but you elected to pick the [possibly outdated] print version over the [possibly up-to-date] web version.

The way scientists themselves use the word ‘consensus’ does not imply any ‘negotiated’ agreement. Each individual scientist makes up his mind without any vote, poll, consultation, or negotiation. So, among scientists ‘consensus’ is not ‘the wrong word’. It is perfectly good. I even gave an explicit example of that.

William Astley

What you meant to say if you understood scientific history is in each case noted above, scientific theory changed as there were multiple observations which we now all agree were paradoxes that were not explained by the ‘standard’ theory believed at the time. It is a fact that there was a delay of decades before standard theory changed and it is a fact that many ignored the paradoxes in question, criticized those who attempted to discuss the anomalies and made the assertion the anomalies created a paradox, and/or created incorrect mechanisms in an attempt to maintain the ‘correct’ consensus theory.
Your selection of solutions (new theories) to attempt to resolve the paradoxes is appropriate as it includes the fundamental physics reason why high altitude regions of the atmosphere are not warming (why more than 90% of the warming in the last 50 years was due to solar magnetic cycle changes) in response to the increased greenhouse gases and the reason why there was a delay in the abrupt cooling of the planet when the solar magnetic cycle decreased and the reason why there is a sudden reduction in the geomagnetic field (ten times faster reduction in geomagnetic field intensity 5% reduction per decade as compared to 5% reduction per century).
There is a physical explanation for everything that happens. There are a multitude of fundamental observations and analysis conclusions that supports the assertion that there is something that inhibits the greenhouse gas affect in the upper region of the stratosphere and that the majority of the warming in the last 50 years was caused by solar magnetic cycle modulation of planetary cloud cover (low level , mid level, and cirrus cloud cover, mechanism affect on cirrus clouds is inverse to the affect on low level and mid level clouds). The greenhouse gas inhibiting mechanism in question does not affect the greenhouse gas effect in the lower regions of the stratosphere. Laboratory experiments that were made to quantify the greenhouse gas effect do not include the variable that inhibits the greenhouse effect higher in troposphere.
If the above assertion is correct the climate change discussions are about to abruptly change due to observational fact that the planet is starting to and will significantly cool. Neutron count in high northern latitudes is the highest ever recorded during a solar magnetic maximum. Solar wind density has dropped by 40%. The solar polar magnetic field is dropping to the lowest value ever measured at this time in the solar cycle. The solar polar field will not recover. If it is an observational fact the sun is in an anomalous magnetic cycle minimum and the planet is significantly cooling the climate war discussions will change. What we are currently observing has happened before.
There is now discussion of crop failures in the prairie region of Canada due to the coldest winter on record in some regions, late spring, heavy anomalous rains during summer throughout the prairie region, and very, very, early snow fall and frosts which is the same ‘weather’ events/pattern that occurred in Europe during the Maunder minimum and that resulted in famine in Europe. It appears unfortunately based on observations that this is a Heinrich event not the 1500 year Dansgaard-Oeschger cooling event which occurred during the Maunder minimum. If solar cycle 24 is the lead in to what causes a Heinrich event, we will need to take action to avoid famine, a 180 degree change in the climate ‘change’ policy.

Ian Schumacher

Good point about ‘consensus’ taking a long time to change and pointing out ignored paradox, especially since we seem to be in the middle of one of these paradoxes right now. 🙂

The solar polar magnetic field falls to ZERO at sunspot maximum in EVERY solar cycle.

Heinrich events are large scale irruptions of icebergs into the North Atlantic, hence not possible during interglacials as there is no source of icebergs.

For the 5 examples listed, you state that “there are people that reject the hard evidence for different reasons of their own, none of them scientific.” Other than the area of Fusion generating solar and stellar energy, I doubt that you have had time to examine all rejections in the other 4 areas to make the categorical statement that NONE of them are scientific.
Yes, for Evolution and Plate Tectonics, one could assert without reading every dissent that “none of them are scientific,” but the history of cosmology surrounding Dark Matter and the Expansion of the Universe involves science-based reasoning on many sides – whether or not such reasoning is correct, remains; but at least the majority of it is not faith-based as in Evolution.

I don’t need to examine ALL the rejections [most of them ludicrous – and I have seen many] if the evidence is hard enough. The shoe is on the other foot. For example, the discussion about Dark Matter goes back many decades with steadily strengthening of the case to the point where continued resistance becomes counter-productive. As I said, there will always be people who for their own reasons will oppose almost anything. Such people cannot be taken seriously.

more soylent green!

Aren’t there also people who for their own reason will support almost anything? Case in point, global warming as the excuse to control every aspect of human civilization?

Nobody is suggesting any regulations or taxes to try to reign in Dark Matter, so it’s a polite discussion. The opposite is true for CAGW

Leonard Weinstein

Expansion of the universe seems reasonable, but the concept of “inflation” as an early stage may be accepted, but still seems unproven to me (it is a hypothesis that seems reasonable, but is not directly supported, it is a plug solution) , and I don’t think the whole story has been told yet. Dark matter is a cop out to explain what they do not understand related to acceleration of expansion rate and some rotation features of galaxies, and use dark matter as a POSSIBLE reason. It still has not been detected, and there may be other reasons for these events. Plate tectonics went against the consensus when it was first described, and for a long while after, but is the present consensus. Your good examples are mostly bad. Consensus is just the majority opinion at a particular time and always subject to change. BTW, the consensus is not pro Evolution, but Creation. I think Evolution is correct, but if you count numbers (even of many scientists) you do not have a consensus.

Your objections are mostly rooted [it seems to me] in plain ignorance. You may [or may not] benefit from reading The amount of Dark Matter is a precise empirical measurement, for example. I’m not here trying to argue against various ill-founded opinions, but rather to point out areas where science has reached healthy consensus on important issues.

Leif, you are putting the cart before the horse. The amount of missing gravitational attraction needed to balance the equations on the gravitational expansion of the universe is know, with a relative degree of precision, but what exactly is the source of that “missing matter” is not known. We can call it “Dark Matter” and “Dark Energy, which is as good a name as any, but it doesn’t mean we know what the word actually means. There’s overwhelming scientific evidence (not consensus, but something much stronger: data) that something is missing, but no consensus whatsoever on what that is. We attach only a few descriptors to dark matter and dark energy, he ones necessary to reconcile the data. Whatever else these things are, is simply unknown, and no amount of consensus on that is possible without a lot more data.
Similar situation with climate science. Consensus is not possible without sufficient data, and with the data, it’s no longer necessary.

That we don’t know what it is does not mean that we should reject that it exists.

Leonard Weinstein

Leif, your comments on my ignorance are very unprofessional. My points were not objections, I was mainly just pointed out the frequent shifting of consensus with time, and the lack of clear consensus where it should be clear (Evolution). Using consensus for anything is a slippery slope. BTW, the article you quoted on dark matter (from 2008) stated that in 5 years (2013) that many more measurements would be made, and increase accuracy. I do not see them. Also, there have been very sensitive dark matter detectors made, and results are negative! We simply do not have all the answers yet. As to the inflation, followed by steady growth, followed by acceleration, do you not see the contradiction here? Why would the expansion switch from one to another? I tell you, the story is not yet complete. We truly know so little about the universe and formation, that it is pure hubris to state we have the answers. Where does gravity come from? What are branes and are there other universes/cosmic foam, etc.? As to your point on healthy consensus, a present consensus supports CAGW. I am a skeptic to that consensus, and I am confident it will be overturned. Who are you to choose what consensus is right or wrong. Only time and information sort that out.

That we don’t know what DM is does not detract from the observational fact that it exists and should not be a catch-all argument for doubting everything in sight. That you don’t see the improved measurements just goes to show that you are not up to date, as I [very professionally] indicated. Newton didn’t know what caused gravity and yet we used his laws to go to the Moon. Here is some information about the progress we have made and here
Cosmology today is a highly precise observational science.

Of course not, and nowhere did I even suggest such a rejection. What is necessary is to form a genuine, testable hypothesis about dark matter and dark energy which can be subject to experiment, detection, or at least compared to the data we have. As of yet, I don’t believe any such hypothesis even exists. At some point, when such theories are developed, scientists will try to evaluate them. The “consensus” at that point might hover around one or several of them as being the most likely to be true. But that consensus is meaningless without hard evidence and data and mathematical support and so on. Once the definitive data is in, the consensus is replaced by a proven theory. So consensus has some value as a way of trying to evaluate an unproven hypothesis, but it’s not the same as scientific knowledge. More a working guide to where to put research efforts.

Dark Matter is an observational fact. To find out what it is, is another matter, subject to all the caveats you list.

No, Leif, DM is not an observational fact. Dark Matter has never been detected. The observational fact is that there is a deficit in all the standard theories that requires some kind of solution. Dark Matter is a proposed solution. But it’s a solution without a working hypothesis that can be tested and proven, much less one that is already observed.
It’s similar in some sense to the aftermath of the Michelson-Morley experiments, which showed no evidence for a cosmic ether. That left a deficit in physics that had a number of possible solutions, but none of them panned out until Einstein came along with GR. But GR wasn’t accepted until its predictions were verified by observational data. Dark matter isn’t anywhere near as advanced a hypothesis as Einstein’s proposals, and it lacks confirmational evidence. The only thing confirmed is that a deficit truly exists, and it is huge. And yes, the deficit is “precisely measured”, but that doesn’t mean that Dark Matter or Dark Energy has been precisely measured, since we can’t detect it at all. We only know how much would be required to fill that deficit. What actually does fill that deficit is not yet possible to say. It may be Dark Matter, or it may be a new theory of gravity that makes that unnecessary. Or both. I’d tend to go with both, but it’s premature to say that we. Btw, I’m not some enemy of DM/DE notions. I just think it’s highly premature to declare them precisely measured facts of cosmology. We don’t even know that they are forms of matter at all, only that something is unaccounted for. That’s the only consensus on the whole matter (pun intended).

No, that was just one of several indications [and the first one to be discovered]. Newer results include the observed fact of gravitational lensing, which allows direct weighing of galaxies, and the height of the bumps of the cosmic microwave background which directly give the ratio of the density of normal matter and dark matter. These are observations and do not point to defects in the standard theories.

Again, that is merely confirmation of the gravitational deficit, not confirmation of Dark Matter. Obviously something is responsible for that gravitational force, and it’s not absurd to assume that it is from matter of some kind. But it’s certainly premature to say that it must be “Dark Matter”, It could also be an indication that gravity doesn’t work as we presume it does, or is even uniform. There’s all kinds of possible answers that don’t require Dark Matter, many of them I’m sure not even thought of yet. Until we know a helluva lot more about these things, and actually detect something definitive, it remains an open question subject to considerable doubt, which is a healthy thing. You seem to be suggesting that doubting Dark Matter is some kind of violation of the scientific method, when it is part of the method itself.

The strength of an argument relies on its capability to predict. The size of the bumps in the cosmic microwave spatial spectrum was predicted long ago from the assumption of the existence of Dark Matter and the assumption that the Universe is spatially flat. Observations much later confirm that prediction which, btw, is independent on any theory of gravitation. I consider the existence of DM to be established. You may dither as long as you like, but that does not change the evidence.

Leif, those observational anomalies used to “confirm” the existence of dark matter only confirm the existence of something that we don’t know about, that creates bumps in the CMB and gravitational lensing, and so. The very fact that dark matter simply doesn’t behave like matter at all (it doesn’t even seem to interact with itself) casts doubt on it being “matter” at all. In fact, the only thing that we can say it has in common with matter is that it produces gravitational fields, and responds to gravitational fields produced by ordinary matter. But since we are hypothesizing some completely new kind of phenomena, there’s no reason to presume that we aren’t just looking at something other than matter that produces gravitation. God knows what. But it sure doesn’t behave like anything we know as matter. It’s “dark”, to be sure, but dark what? Until we know the what, we have no business claiming it’s matter. It may well be, but it’s far from certain. And if we are only looking for matter, and not other things as well, we may be wasting a lot of effort.

For the zillions time. There are not gravitational anomalies. Instead they are direct consequences of Newtonian gravity. And the heights of the bumps in the spatial spectrum of the cosmic microwave background have nothing to do with gravity, but with the speed of sound in the early universe [freshman physics]. You seem to particularly dim [or perhaps just unwilling to learn] with respect to this.

Matter is that which has mass. As simple as that. There is no requirement that matter interacts with electromagnetism [so that we can see it]. Neutrinos are a good example of matter that does not interact with electromagnetism so will always be invisible, but are still matter, albeit with only a tiny mass. Perhaps you deny that neutrinos are matter, or that they even exist.

Let me also point out that in an earlier era, science assumed that heat was an actual substance, a form of matter, called phlogistan. This wasn’t a crazy theory, because heat really did seem to act like a substance flowing from one object to another object. Later research found it was explicable by something else entirely than a fluid substance. The same may well be true of Dark Matter. It may look at first glance when very little data and understanding is available to us, to be some kind of invisible phlogistan-like substance that accounts for all this observational data. But it may turn out to be something else entirely, and not explicable by trying to explain it through the physics of some kind of mass moving through the universe. Sometimes, the realities are hard to grasp or even conceive of, and we fall back into thinking in terms of the conventions of what we know. That seems to be the case with Dark Matter. But the universe keeps proving itself to be stranger than we can think. So we have to re-think what we think we know. I don’t think Dark Matter will be understood without a whole lot of re-thinking.

What Dark Matter is, is irrelevant for the fact that it exists. Just like heat exists, even if people didn’t know what it was.

Leif, cool down. Yes, I know the bumps are assumed to be from sound waves passing through some sort of substance, and that the lensing is assumed to be a result of some form of matter moving through a galaxy. I’m just pointing that these are assumptions about what is being observed, not the actual observation of some new form of Dark Matter. What is creating these anomalies (and I don’t mean just gravitational anomalies, but all of them), is not known. It may be an actual form of matter, or it may be something else that is being confused with matter. Or it may be that it’s something else entirely, and that Dark Matter is as illusory to cosmology as phlogistan was to thermodynamics. Way too early to tell. And it probably won’t become clear in our lifetimes.

The bumps are caused by density differences. Density requires mass, mass is matter. what else is there to discuss?

No, lensing is caused by ordinary [and well-understood] light passing through mass [i.e. matter]. Nothing mysterious here. Your use of ‘assume’ is silly. If I observe the light from a star, you would say that I ‘assume’ that I’m looking at a star. I will say that there is no assumption, that, indeed, I’m observing a real star, not just ‘assuming’ so.

This we can agree upon, except that calling it matter already makes a presumption that it is a form of matter, and saying that we know it to be a form of matter based on the evidence is highly misleading. It’s a useful hypothesis, but not a confirmed one. The confirmation is only that the mystery is a real one that needs to be solved somehow by something new to physics. Presuming that it is matter is like presuming that heat is a substance. A lot of misleading deductions get made that only steer the science in a single direction that may well be the wrong one.

The definition of matter is that which has mass. So you are denying that dark matter has mass, even though it exerts gravitational influence [which we ordinarily use to measure the amount of mass]. I cannot follow you in your particular form of denialism.

The only bumps are created by the ratios of matter to gravitational strength, and between ordinary matter, and whatever it is we call “dark matter”. It doesn’t have to be a form of matter to change that ratio, it merely has to produce gravity. The density ratio and the acoustic anisotropies would still be same. It does not have to be a substance with “density” causing this, only something that is actually not at all “matter-like” would do the trick. Hence, we call it “dark matter”, meaning “something that produces gravity but doesn’t interact with things, or even with itself, the way matter does”. Sort of like phlogistan.

No, the bumps are caused by the pressure of sound waves versus radiation pressure. Nothing to do with a theory of gravity. Again: that which has mass and density we call matter, regardless if it interacts with electromagnetism [e.g. neutrinos]. If you choose not to call that matter you marginalize yourself. Fine with me, there are many like you out there.

The definition of matter is that which has mass.
Yes, but that equation is not one that can be inverted. We cannot say that anything which produces gravity is a form of matter. Not if we are required to invent new forms of matter that don’t otherwise behave like matter at all. It may be that Dark Matter really is a form of matter, or it may be that it’s something else entirely, previously unknown (just as Dark Matter was previously unknown) that creates matter. Again, think of phlogistan, which turns out not to be a substance of matter at all, but a form of kinetic energy. What we call gravity also turned out to merely be a curvature of space. Dark Matter may be something like that, as yet unimagined.

We can say that, and we do. We define the word matter to mean that which has mass [and density], regardless if it interacts with electromagnetism. So, being able to see something is not part of the definition [or concept] of mass. About curvature: “Mass tells space-time how to curve, and space-time tells mass how to move”. Mass is matter, and matter is mass. What Dark Matter is, imagined or not – understood or not, has no bearing on whether it exists. It does. Occam’s razor tells us not to invent new things when the old will do. “Plurality must never be posited without necessity”, and there is no need to posit am unknown thing when good old matter fits the bill.

Ugh, typo. Should read “that creates gravity”, not “that creates matter”

To be more clear, the acoustic anisotropies are a function of baryonic pressure, not any pressure related to Dark Matter, which of course does not interact with anything or add anything to those acoustic signatures but its gravitational effects. So there is no acoustic density to the Dark Matter being observed. Instead, when the baryonic pressure falls below the amount that allows light to escape, it does so depending on the variations in baryonic pressure that we call acoustic sound waves. As it does so, we notice the variations in this escaping light due to the fact that a large percentage of the gravity is NOT found in these baryonic density waves. THere is no sense in which Dark Matter is thought to be a contributer to these waves. It’s density is calculate purely on the basis of its gravitational contribution, not any ability to conduct sound waves, of which it has none.

You are beginning to catch on. What we know is the total density and the baryon density, yielding the dark matter density as the difference between the two. That still does not change the fact that dark matter has mass [exerts gravitational influence – not ‘anomaly’] and is therefore matter and exists. Your denial of this is puzzling, but perhaps typical of an unwillingness to accept modern cosmology. I, for one, do not see the need to invent new concepts when old ones will do.

Yes, I agree. But that is not the issue here. We are talking about gravity, and the possibility that gravity (meaning the curvature of space) can be produced by something other than mass/matter. Certainly we don’t have any other examples of this, but the same can be said for the phenomena being called “Dark Matter’. So both are possible solutions to the problem. It’s not that only some new form of matter/mass could explain this phenomena. So could a new form of energy or force, or a new way of understanding existing and known interactions within the standard model, that produces gravity by means we do not yet know. It’s just as logical as positing a new form of matter that cannot be detected by any other means, and that really does not interact in any other way with either ordinary matter or itself. There is no “fluid dynamics” of Dark Matter being detected in the CMB, but precisely the lack of it. And the measurement of that ratio is a valid way of looking at the gravitational equivalency between this way of generating gravity and the known way (through mass), but it does not otherwise confirm that we are looking at a form of matter/mass. It’s something new, and that means it could also be a new way of producing gravity (the monopoly of mass may be broken here)

Again, you are unnecessarily inventing new concepts, where none are needed. And still, what we call it does not change the fact that it exists [which you deny]. You prefer to think it is mysterious, I think it is not.

We do: neutrinos have mass but do not interact with electromagnetism, i.e. cannot be seen. In fact it was once thought that neutrinos were the dark matter. For various reasons we don’t think that anymore.

Normally I would agree. But the fact that the ONLY thing Dark Matter seems to have in common with ordinary matter is that both produce gravity changes the common sense rostrum of not creating new things. Matter/mass is not the default position any longer, until at least we can find some other commonality between them. That Dark Matter obeys no detectable form of matter-like behavior, and doesn’t even seem to interact with itself, or move as a fluid dynamic that can conduct sound waves, really casts doubt on the classification of it as a form of matter/mass. So it’s not just it’s inability to interact with electro-magnetism that’s troubling. It doesn’t even behave like a substance with mass at all. In fact, I would not be surprised at all if it turned out to be massless, which would account for its lack of fluid dynamics. And thus not even an “it” at all, but something quite different. Phloghistan, after all, is massless precisely because it isn’t a substance at all.

It doesn’t even behave like a substance with mass at all
Yet is is detected by having mass. Your continuing denial of the existence of what is called Dark Matter is wearing thin. I for one do not share your denial. Perhaps you only deny that DM should be called ‘Matter’. I see no reason it should not, defining matter as that which cause the curvature called gravity. The Higgs field is probably responsible for mass/curvature in the first place. You want to postulate an additional mechanism. That is inventing plurality where none is needed.

Another point would be that if Dark Matter has mass, it should also have Higgs Bosons. But since it’s not a form of ordinary matter, how could that be? So even the very hypothesis of Dark Matter seems to imply alternative means of having mass that produces gravity, rather than using the Higgs Boson. Why not eliminate the middle man, and go straight to the gravity-producing mechanism that doesn’t use the Higgs Boson?

That is inventing plurality where none is needed. But do I sense that you accept the existence of what is called Dark Matter, but simply object to the moniker ‘Matter’?

Yes, the moniker “matter” is what troubles me. “Dark” is just fine. As for plurality, when we are dealing with such huge “dark” unknowns, it’s best to have multiple solutions and keep everything open and not create new catechisms that aren’t warranted. I would in no way suggest we stop pursuing the dark “matter” hypothesis, but also look at everything else as well, and not reify it with some sort of false consensus that is really just a fall-back position.

Bottom line: dark matter exists. There is general agreement that it is matter with mass. People are already designing experiments to look for the particles [some even claim to have seen some]. The default assumption must be that dark matter is Matter and not any yet unknown non-matter, non-mass, mystery. Until we get clear indication that Dark Matter is something un-imaginable, we should not assume that it is. It could well be that ALL our theories [General Relativity, Quantum Mechanics, Maxwell’s Equations, etc] are totally wrong, but unless there are some good evidence for that we cannot proceed on the assumptions that everything is unknown and that we are totally in the dark [so to speak]. This is my general objection to your attitude.

I do not deny the existence of some phenomena causing these observations. But since all of the observations boil down to gravitational factors, that is all that we have confirmed – something that creates a gravitational curvature of space. Obviously that could mean that it is something with mass, but it since we see no other signs of matter involved, it could also be something else as yet unknown. Since we have no examples of matter with these characteristics, it is not crazy or superfluous to hypothesize that there are other ways of producing gravity than we as yet know about. Nor is it a form of denial of any facts.
Neutrinos also interact with the weak nuclear force. They are also directly detectable and have been detected countless times. Their mass is still a matter of theoretical equation-fitting, required by the current standard model but not detected as of yet. And it’s not at all your standard form of mass. It’s even been suggested that it doesn’t use the Higgs Boson to fulfill its mass requirements under the standard model. So that too is actually a factor in favor of the notion that there’s plenty of room there for other solutions other than the standard “dark matter” hypothesis. Of course, I just remembered that there is no standard dark matter hypothesis at all. It hasn’t even gotten that far.
It’s hilarious for you to say that there’s no mystery about Dark Matter, when you also admit you have no idea what it is. Except, that somehow you know that it must be a form of matter. The cognitive dissonance is huge in this one.

But such alternative mechanisms already exist. They are not wholly outside our imaginations. You brought up neutrinos, so surely you are aware that one of the leading theories about neutrino mass is that it is the result of majorana fields, rather than the Higgs Boson. In fact, there are major scientists trying to test this right now, just as some are seeking to find dark matter. So it’s not some kind of universal consensus as you are trying to make it out to be. If dark matter is something like neutrinos, then its gravitational force may come from something even more esoteric like that.
I don’t mind your claiming that matter/mass is the default position for first looks, but since we are in wholly new territory, there’s no reason to assume that the default is in any way correct. I would be willing to bet that this whole matter will lead to a major new phase in physics at some point, similar to the disruptions of GR and QM, both of which did not rely on some kind of default. My friends in the field, who have much better credentials than you, are even more out there in private than I am. And I’m talking about a fellow who designed the detector for the LHC, and pretty much every other detector out there. I’m actually pretty conservative on this. These fellows have been of the view that the standard model and GR are broken, and can only be fixed by radically new thinking. Of the kind that won’t come from folks like you.

So, now we are appealing to authority… Fair enough as experts usually know more than most other people. Physicists working in the field are allowed to speculate, that is how progress in made. The rest of us have somewhat less freedom in that regard. You started out by denying that the phenomenon called Dark Matter existed. The name we give it is not material. Ever since the 1930s the phenomenon has been called Dark Matter [Dunkle Materie]. There is general agreement that Dark Matter exists. Most physicists accept that it is Matter and many are searching for the particles involved. At the same time, it is important to pose ‘what if’-questions and see where they lead, but those are not meant to overthrow the generally accepted paradigm. Sometimes they do, but that is very rare and I don’t think that is the case here. Some people, including, it seems, you are conflating the probing at the borders of the known with a licence to throw away all solid progress already made.

Of the kind that won’t come from folks like you
And apparently not from the 263 authors of
Dark matter is an established fact [as much a fact that is usually required for being a ‘fact’.
The density of Dark Matter is found to be 5.41 times that of baryonic matter. [section 3.3]

My general impression as an outsider to the field is that there’s something of a discontinuity between the astrophysicists and the particle physicists on the question of dark matter. Most of the people I know are particle physicists, and they are much more skeptical of these deductions from astrophysical observations. It would seem natural that you are more in touch with the astrophysics community, and so naturally agree with their assumptions and conclusions. My personal impression is that the astrophysicists are painting themselves into a corner, but that’s not a big problem except for them, and they seem happy with it for now. Truth will out eventually, one way or the other. Thanks for the conversation, however heated it may have gotten.

Physicists also had precise calculations of the density of the cosmic ether before Michelson-Moreley. And I bet they had some good numbers on the characteristics of phlogistan long ago also. Making deductive calculations from unproven premises makes for hilarious after-party embarrassments.

Robert B

Science is where you have repeated the work yourself. Everything from collecting the data to the checking the maths. We keep forgetting this because its impractical to repeat everything and this is where consensus becomes important.
Most sceptics are sceptical because they did check something that was part of the consensus and it was found to be dubious. This makes the consensus irrelevant.

Probably just shows examples on confirmation bias. Most skeptics are not capable of checking anything.

David A

Robert B
September 9, 2014 at 9:06 pm
Leif Svalgaard
September 9, 2014 at 9:10 pm
Leif, how did you come to this assertion, Did you do a scientific study? (If not perhaps you should yourself check before making such an assertion) If so I hope it was better then the Cook study.
Do you really think most people are incapable of reading a global T graph and seeing no warming, and at the same time finding out that there is no increase in hurricanes, droughts etc.; an endless list of failed predictive disasters?

Just looking at other people’s graphs does not qualify as a ‘study’ in my book.

I don’t know about you, Leif, but for me EVERY scientific truth is valid until proved otherwise.
After all, this is the meaning of skepticism, isn’t it?
The trick is to supply evidence.
I do not see one in climate science yet. I do see a lot against the CAGW theory, though.

I disagree. Consensus based on hard evidence is worth exactly zero compared to the hard evidence. And no amount of consensus bypasses the need for hard evidence.
Btw, not one of your examples relies on consensus for validity and dissenting scientific views do exist (even when having less support than those mainstream for a variety of reasons). Inform yourself.

Sometimes the hard evidence is simply ignored and that is where consensus becomes important. Hard evidence without consensus is worth exactly zero.

Ian H

Dark matter is a very odd choice. We don’t know much about it at all. It really is just a fudge factor to get Einstein’s equations to generate the right answer. How can we have consensus about something we don’t understand? Indeed it is entirely reasonable to hold the position that Dark Matter may not exist at all and if we just fixed up Einstein’s equation the need for it to balance our equations would disappear.

This has nothing to do with Einstein’s equations. The observational evidence for DM does not rely on those. And as for not knowing what it is: we happily use Newton’s equations about Gravity, even though he refused to speculate about the cause or reason for gravity.

richard verney

There are two distinct differences between the examples cited by you and climate science.
First, in the vast majority of your examples, no scientist in the field would claim that the science is settled in that field, and most scientists would readily accept that there are large lacunas in our knowledge and understanding of that field of science.
Second, they are not used to dirve political ends, and not being used to impoversih society and keep the 3rd world un developed.
Whilst I would not be impressed by consensus in the field of climate science, I would have no problem in their being consensus in a field which is in its infancy, if it was kept to being the back water that that science is, and was not being used to drive political ends.

Leif writes “Consensus that is based on hard evidence”
The case for dark matter is one based on circumstantial evidence, not hard evidence.

Dark Matter is an observational fact. We lack the theory, but we know the presence of DM from its gravitational effects. I consider that hard evidence. An example: we observe a spectral line of a certain element in the light from a star. That is hard evidence that the star contains that element even though we have never held a piece of the star in our hand.

I think you missed the point. We have the evidence – but not the substance. Dark matter is a holding name for what has not been discovered yet. That is the point. it may be unicorns. We know something should be there from the evidence, but have not ‘discovered’ it yet.

There is confusion here. Dark Matter, like Gravity, has been detected and exists and we know rather precisely how much of there is. We do not know what it is, as we did not know what Gravity was before 1915, but to deny the hard observational evidence is just plain silly. But there is much other silliness around as well, so one should not be surprised.

The “effects” of dark matter have been detected. Dark matter itself has not been. So we know more about what it is supposed to do, than we know of it. The distinction is critical. Long before the neutron was “discovered” the properties were described and quantified. We knew it was there, but had not yet “found” it. Dark matter is the same way.

Pat Frank

Poor analogy, Leif. We can measure atomic spectra right down here on Earth. So far as I know, there is no direct detection-level data for dark matter.

What is an observational fact is that the galaxies move as if there were more mass there than we can detect. Its a compelling argument but your understanding on “hard evidence” is way off Leif.

no, the galaxies move according to Hubble’s law, not requiring more mass, nor dark matter. Galaxies rotate in a manner consistent with DM and the existence of clusters of galaxied does the same, but the amplitudes of the bumps in the spatial spectrum of the cosmic microwave background determine the amount of DM [i.e. non-baryonic matter] regardless of how the galaxies move. The amount of gravitational lensing shows us the amount of DM and its distribution in space, again regardless of how the galaxies move. It is becoming tedious to point this out again and again. Perhaps this is a result of the new threading of comments that scatter comments among several different threads.
Here is a review of the evidence for DM:
“The existence of Dark (i.e., non-luminous and non-absorbing) Matter (DM) is by now well established [1,2]”
The emphasis have [because of the strong consensus] moved from whether DM exists to what DM is and how one might go about finding out.

The Bullet Cluster is a particularly good piece of evidence for the existence of Dark Matter:
Of course, as with all evidence, there are people who deny the evidence, sometimes with ingenious arguments which usually do not sway serious scientists. You may be able to google some of the more silly ones.

Again, Leif, these gravitational anomalies only prove that something is creating a gravitational anomaly. It’s circular reasoning to say that this hard evidence that Dark Matter exists, since that’s just the name we are giving to whatever is causing the gravitational anomaly. Of course “Dark Matter” exists, if that’s they very way in which it is defined. But that proves nothing more than that there’s a gravitational anomaly that must have a cause of some kind. If we have no idea what “Dark Matter” is, other than something that creates gravitational anomalies, we have not further advanced our understanding of those anomalies. If that’s not true, please tell me what more is understood by calling that cause “Dark Matter” that we didn’t already know from the anomaly itself. I’m not being facetious either. I’d really like to learn something here rather than just having this circular argument about nomenclature.

Again, the bumps in the cosmic microwave background that shows us how much dark matter there is is not a gravitational anomaly, but have to do with propagation of sound waves. Perhaps it comes down to defining what ‘matter’ is. A generally accepted definition [the consensus if you will] is that matter is what has mass, and therefore has a gravitational effect: gravity = mass = matter

Leif writes “no, the galaxies move according to Hubble’s law, not requiring more mass, nor dark matter. ”
Wow. replace “move” with “rotate”. You should have understood that from its context Leif. This conversation is fruitless.

It isn’t consensus when the evidence is overwhelmingly present anyway. It’s consensus when the evidence is tentative and in question, but scientists feel the need to come to some kind of conclusion in any case, that’s not warranted by the evidence, but is necessary for some purpose outside of science.

That is not the way ‘consensus’ is used among scientists. For an example:
Consensus means that the evidence is so good that even people who earlier disagreed strongly, now accept the finding as a fact.

I’m talking about the way “consensus” is used in climate research, or in general political discussion, which these days amounts to the same thing. When the evidence is overwhelming, there’s no need for a consensus, because the evidence speaks loud and clear.

In science there is still need for consensus because some people refuse to accept the hard evidence, e.g. for Dark Matter. The danger is that the political aspect of ‘consensus’ will pollute its scientific meaning [for people who do not know the difference]

Lief, there is no “hard evidence” for DM/DE. There’s hard evidence for a deficit that something must be out there filling in, but DM/DE is merely a proposed solution to that deficit, not a confirmed one. As I said above, the consensus is that the deficit is real. If there’s a consensus that DM/DE is what fills that deficit, it’s not something based on hard evidence, but on not having any better ideas. When/if DM/DE is actually detected, confirmed, and understood, then there’s no need for a consensus anymore, it’s just a fact. As I’ve said, my guess is that there will need to be a major revolution in physics before any of that can happen, just as with Einstein’s GR. And that will wipe away most of the current notions about the whole issue. It might even make DM/DE go away entirely, or completely change our concept of what fills this cosmological deficit.
As I also said before, the “consensus” on things like DM/DE is mostly about scientists deciding where to put their research energies and monies. It doesn’t mean these things are established truths, only that they are where the most productive research is likely to come. I’m not at all opposed to that way of using a “consensus”, and I think research into DM/DE is a fine use of money and brain power. But let’s not put the cart before the horse.

As explained in another comment, the ‘deficit’ is just one of several pieces of evidence. I am sometimes amazed at people’s wish to avoid learning something. We are in a Golden Age of discovery right now, and yet, you will not take the trouble to inform yourself. Go figure.

Leif, your logic is very similar to that of warmists. Yes, we have warming, and yes, GHGs have radiative properties that can produce warming, therefore the warming is produced by GHGs. Unfortunately, this presumes that nothing else could be responsible for the warming.
With Dark Matter, it’s even worse. Yes, we have a gravitational deficit, not just at the universal level, but at the galactic level, and no none form of matter that could fill that deficit, so it must be an unknown form of matter. Let’s call it “Dark Matter”, and declare we have discovered and confirmed and measured it. But since we don’t even know what Dark Matter is, and have never encountered it elsewhere, it could literally be anything, and doesn’t even have to be a form of matter. It’s just something that produces gravity. But rather than saying we just discovered something that produces gravity without being a form of matter, we choose to conceptualize it as “Dark Matter”. Not unreasonable, of course, but hardly convincing. Another example of the humility scientists need to acquire when it comes to their claiming to know how the universe works. We are very, very early in the scientific pursuit of knowledge about these things. Show some of that humility for a change.

Again, you are not up to snuff. DM is not a deficit but an excess and the evidence for its existence does not depend only of a theory of gravity.

Leif, your grasp of the issue at hand is what is lacking. By “deficit” I did not mean a lack of gravitation, but a lack of sufficient matter in the universe to explain the gravitational forces observed. That deficit is explained by the hypothesized presence of Dark Matter.
And clearly we don’t have an adequate theory of gravity if it requires the presence of undetectable matter (not to mention undetectable “Dark Energy” to explain its observable effects. We should hardly be surprising.
And by undetectable, I don’t mean to deny the observations of these gravitational anomalies. I mean the fact that we can’t detect something here on earth or in nearby space that supposedly constitutes over 80% of the matter in the universe. Is there a plausible theoretical explanation for the absence of these gravitational anomalies in our corner of the universe? Again, I don’t ask that rhetorically, but for real edification of the issue. Because if we could detect it here on earth, and study its nature, and then make extrapolations to distant phenomena as you have stated, that would be a genuine confirmation that we are really observing a new form of matter.

Again, the observation of the bumps [caused by ordinary sound waves] in the spatial spectrum of the cosmic microwave background tells the ratio between the amount of dark matter relative to that of normal matter and does not rely on gravitational anomalies of theories of gravity.

Exactly. As usual in science, what we have here is a consensus of scientists as a consequence of the consensus of evidence. Only robust counterevidence, and a robust alternative theory, can overturn that. Conspiracy theories, stolen emails or a 200 million hit count don’t do much to change this scientific fact. (it may confuse public opinion though… and that’s the point, of course)

David A

Failed predictions in conjunction with failed climate models however do. And desperate money grubbing academics and scientists cannot change that.

I see. Research grants are an economic power that dwarf the vunerable and fragile multi-trillion dollar fossil fuel industry. Predictions have been pretty good, BTW (Rahmstorf 2011), even if not perfect. We’re talking about real science, of course, which is NOT the case of ‘skeptic’ predictions.

You write

You are joking, aren’t you?
There is no evidence for man-made global warming; none, zilch, nada.
If you can find one jot of such evidence then publish it because you will then certainly be awarded at least two Nobel Prizes.
Three decades of research conducted world-wide at a cost of over US5$billion per year has failed to find any such evidence. Ben Santer claimed to have found some such evidence in the 1990s but that was soon found to be an artifact of his selecting a short sequence of data from the middle of a data set.
The Climategate emails that were leaked as part of Climategate – including the leaked emails from me – were not “stolen”.
In so far as there is a “consensus of scientists” then it has to be the Oregon Petition which refutes the global warming scare because attempts to obtain similar numbers of scientists to support the scare have all failed.

Empirical evidence of CO2 increasingly retaining infrared in the atmosphere… CO2 isotopical composition indicating fossil fuel origin… Yes, if you discard all the evidence, there is none left. Zilch, nichts, niente, nada.
Oregon petition is a great project. There are few scientific petitions that include Hawkeye from MASH and Geri Halliwell. And come on, you don’t debunk science with a petition. You thought you did?

Your reply to me says in total

Come on, even a third-rate internet troll usually manages to do better than that!
The increase to atmospheric CO2 concentration may or may not be anthropogenic (i.e. a result of human activities) or natural in part or in whole
The direct indication of the isotope data is that at least two thirds of the CO2 is NOT of “fossil fuel origin”.
For sake of argument, assume the increase to atmospheric CO2 concentration is entirely anthropogenic, then there is no indication of CO2 increasingly retaining infrared in the atmosphere.
Assume that CO2 is increasingly retaining infrared in the atmosphere, and that does NOT mean there will be an inevitable and discernible increase to global average surface temperature anomaly (GASTA). There could be a change to lapse rate or alteration of thermal transport rate(s) around the climate system.
Yes, if you tell lies as evidence then you can pretend some evidence exists for anthropogenic global warming.
I repeat, if you can find any evidence for anthropogenic global warming then publish it because you will then certainly be awarded at least two Nobel Prizes. Three decades of research conducted world-wide at a cost of over US5$billion per year has failed to find any such evidence.
The Oregon Petition is not science. I said it is not science. It is an answer to untrue propaganda such as ‘Cook’s cooked 97%’. You lie when you pretend I said otherwise. And it is a foolish lie because people only need to scroll up a few inches to see what I did say,

Strong words, man. Much more like someone who wants to intimidate, than someone who’s confindent on the findings of his published work – E&E, of course. Please give Sonja my best.
Since we emit roughly double as much carbon than the amount that stays in the atmosphere, where does all our carbon go? And what is the misterious natural source of carbon that became incredibly active exactly when we started emiting a lot of carbon?
Does your paper address these questions?

Yeah, didn’t think so…

I repeat, if you have managed to find a jot of evidence for man-made global warming then state it because nobody else has managed to find such evidence.
But, of course, being unable to provide any evidence – as trolls always do – you try to hide your failure to provide any evidence by changing the subject to silly questions and ridiculous insults.
Almost all the carbon circulating in the carbon cycle is in the oceans and during each year the oceans release then sequester several times more CO2 than the total of all CO2 emissions from human activities. You say you cannot think of where the carbon emitted from human activities goes and that is not surprising because yoju have yet to demonstrate an ability to think.
At issue is what the level of carbon dioxide in the atmosphere would be in the absence of the human emission. Without that knowledge we cannot determine what – if any – effect the emission from human activities has on the amount of CO2 in the air.
And your trolling does not and cannot alter the fact that there is no evidence for man-made global warming – none, nada, zilch – which is why you have not presented any. Pointing out your failure is not “strong words” and is not “intimidation”. It is an invitation for you to ‘put up or shut’: provide some evidence if you have found some.

Man, why so shy of sharing the results of your own paper? Are the best arguments in it ad hominems like your post? Thought so. A troll’s attitude, by the way. Psychological projection is a common trait among deniers. Paranoia about conspiracy theories too.
Increase in downward longwave radiation, and its decrease at the top of the atmosphere are direct evidence of the enhanced greenhouse effect. The frequency spectrum analysis of this rediation point to increase of greenhouse gases as the cause, mainly CO2 (disagree?). Our own emissions are more than enough to justify all observed increase in CO2. You didn’t even deny that (do you?). You just point vaguely to the ocean as a place where all our carbon went – and presumably that’s where all the atmospheric carbon came from (right?). Exactly when we started emiting our own CO2. Right.
So, summing it up:
– all our carbon went to the ocean.
– the mean ocean started releasing a lot more carbon when we released ours – but the atmospheric CO2 is not human in origin. The ocean just wanted us to look bad.
No wonder it just got to be published at E&E.

No And each of these theories had to overcome an existing consensus. But Darwin’s theory, for example, has proven wrong in several details, despite a consensus.

more soylent green!

Many of us are unaware Darwin’s theory of evolution has been proven wrong. Why does it persist as a scientific theory? Can you provide some proof?
BTW, I’m aware of much legitimate criticism of the theory, but none that rise to the level of disproof. Macro-evolution in which dinosaurs evolve into birds, is extremely difficult to scientifically “prove” [a misnomer, I know] because of the spotty nature of the fossil records. It’s also hard to show how complex organs, such as the human eye, evolved from simpler tissues.
RELATED: I don’t know of anybody who has created computer models as proof of evolution, either.

more soylent green!

You make some very good points. However, in climate science, term “consensus” has been abused. Disagree with one or more points of contention with legitimate scientific criticism and you will be dismissed and ridiculed because there is a “consensus.” “Consensus” is used to avoid debate and avoid discussing issues which make climate scientists and global warming activists uncomfortable. “Consensus” is used to ridicule and squash dissent.
How many times have we heard — “It’s settled science. There is a consensus.”
Consensus which persists dispute contrary hard evidence is an insidious problem.

Consensus might well be “valid” if it recognizes empirical evidence, but it is neither necessary nor sufficient for supporting the validity of an hypothesis. It is simply be an emergent social reality (among interested scientists) that may be employed as an authoritarian short cut in an argument. And, let us not forget that someone with the last name of Svaalgard persists in pointing out that sunspot data is problematic and that “consensus” generalization based upon misperceptions of the reliability of that data are therefore quite wrong. Should we reject his explanatory work simply because it contradicts a consensus? I don’t think so.
There is a “consensus” that the planet is warmer now than during the depths of the Little Ice Age, and for that matter far warmer than at the depths of the Wisconsinan glacial. There also empirical evidence that the planet is cooler now than during the early Holocene, and also good empirical support for highstands of sea level during the Holocene that are ignored by the “consensus.” There was also for a time a consensus that AGW appeared to be a reasonable hypothesis based upon Arrhenius’s laboratory results. In contrast, the models of the IPCC reflect a “consensus” that the world presently must be warmer than the available real-world data show it to be. Indeed, the deviation between the ensemble of models and empirical data now appears to be statistically significant. That “model consensus” is therefore mistaken. The mistake could be minor – simply over-emphasis or mistaken sign on the influence of CO2 on weather. It could however be major: important elements left out of the physical model of weather, or even a mistaken physical model of how weather emerges. So, it would seem that the AGW consensus may well be as faulty as the “consensus” regarding the influence of sunspots and solar maxima on weather.
Consensus is a vox populi fallacy and is irrelevant in science. All it tells us is what a large number of people think; not whether they are right in what they think or not.

‘Consensus’ does not mean that the subject is necessarily true. but only that most scientists have stopped arguing about it and accept the subject as a basis for further work. Without such consensus most work will be disconnected. Scientific consensus results when the evidence becomes strong enough that objections are marginalized. There is no ‘negotiation’ taking place. So ‘consensus’ means something else than what most lay people think. It is like the word ‘theory’. In science, that word means ‘a shorthand for a large body of facts’ and is a description of our knowledge about the subject, while to most lay persons it means something that is uncertain and hardly supported by evidence, almost akin to mere opinion. Scientific consensus is good just as scientific theories are good.

Leonard Weinstein

Leif, there are several stages to ideas: Guess, hypothesis, theory, and law. The difference is large amounts of supporting DATA and total lack of falsification. When an idea becomes a theory that is supported by much data, and especially when it rises to the level to be called law, you can say a scientific consensus has been reached, but after the fact. The theory or law does not become enabled by counting heads, but by the supporting evidence. Even laws can be overturned (Newton’s by Einstein, and Einstein by quantum mechanics), although they may still be useful in limited ranges. If scientists are so biased that they object to a well established theory or law, they need to falsify some factor. Consensus plays no direct part to this. A consensus forms on a theory or law after it is established, it does not cause it to be valid. Many consensuses are later overturned. The only point to accepting a theory or law is strong supporting evidence, and lack of falsification, not a consensus (which is more apolitical response).

Sir, although not a “scientist” in the sense of peer reviewed published papers etc., I must point out there are a considerable number of scientists whose credentials in physics, astrophysics, astronomy, biology, and other sciences who seem to have rejected the “hard evidence” with what appears to be sound scientific reasons. Skepticism of current “consensus” science should not be limited to “climate science” at all, nor should the Cathedral of grand poohbahs be allowed to shunt evidence of alternative explanations of, e.g., currently observed physical astronomical events or conditions aside for the sake of invested careers. The current state of astrophysics is entirely a mathematical construct which seeks to invent wilder and wilder explanations to fill the gaps in observed reality- just like the global warmists. Astrophysics models continue to fail, while mathematicians continue to scribble new equations to justify their “theories”. The red shift was called into question nearly 80 years ago, along with the great god Einstein’s work, but the Cathedral marches on with the white coated priests pontificating for their worshipful audience.

Leif Svalgaard: I don’t know enough about the Expansions of the Universe, Dark Matter, and Fusion to answer your statement, but I was taught what is science, defined by the scientific method, and evolution—you need either to change the methodology of science, as taught by Dr. Richard Feyman, Dr. George Gaylord Simpson, Dr. William S. Beck, et al, or change the definition of the Theory of Evolution, as taught by Dr. George Gaylord Simpson, Dr. William S. Beck, Dr. Stephen Gould, et al, in order to make Evolution a scientific theory. Absent changing one or the other, Evolution cannot be a scientific theory. Simple logic teaches that.
Evolution is a theory, but not a scientific one.
Yet there’s a consensus that evolution is a “scientific fact”, a consensus built up the same way as that for CAGW—refuse to debate, take editorial control over the “scientific journals” and refuse to publish papers by those who don’t toe the line on Evolution, if a professor use his influence to prevent people who don’t believe in Evolution from getting advanced degrees in science or at least make it more difficult, again as a professor or dean hire only true believers as professors and fire any non-believer who might have slipped in, call those who don’t believe “ignorant”, “anti-science” and a spate of similar epithets, and so on. This is a manufactured consensus, not one based on the evidence.
As for Einstein’s Special Relativity, there were good objectors to his theory based on good scientific reasoning, but they were marginalized as well. For example, Tesla found that Relativity and Quantum Mechanics predicted different results than what he was finding in the lab. Dr. Thomas G. Barnes from UTEP, after retiring, redid the math for the 1911 experiment and found a mistake—one of the values used in the formulae was incorrect. The corrected value was discovered decades after the experiment. When he plugged in the corrected value, it significantly changed the results such that had the corrected valued been used in 1911, Special Relativity would have failed.
“Consensus” has gotten a bad reputation because of its misuse in examples as above.

NZ Willy

Leif Svalgaard stated: “Consensus that is based on hard evidence … examples are … Expansion of the Universe, Dark Matter, … Plate Tectonics.”
I must, Cassandra-like, point out that each scientific discipline has its area where things are unclear. Today’s science has marvellously come up with a new technique for dealing with the unknown: they quantify them, and give them a label. In astronomy, the unknown factors are “dark matter” (ie, 90% of matter is missing) and “dark energy” (~80% repulsive energy missing). All it actually means is that these are the quantifications of the discrepancy between theory and observation. Note that “dark matter” does not have to be matter at all — so for Leif to state that “dark matter” is “hard evidence” is, well, waaay out there.
But it gets worse. Consider thermodynamics, a picturesque science which all science undergraduates enjoy and which imbues them with purpose, as enthalpy and entropy combine to give a perfect model of energy conservation, a thrilling experience for the impressionable — until you realize that entropy is just another form of dark matter — simply the gap between experiment and theory. The fact is that scientists have no effing idea where the lost energy goes, so they quantify it and call it “disorder”. It’s just another quantified label which could have been written as “qwertyuiop” (as Feynman might say).
Ptolemy could have quantified the discrepancy between his orbitals and the observed orbitals with “dark orbitals” of 10%, and held Copernicus at bay (ignoring Aristarchus for the mo, who uncovered all this 2400 years ago). We could be living in a world of “dark orbitals” today.
Lastly, Leif, plate tectonics, which were consensus-like denied for 50 years. No use parading them now as an affirmation of “hard evidence consensus”. I consider Leif as a glorious bright light of science, but in the big scheme of things, it’s all relative.

Using gravitational lensing [look it up] we measure the total mass of a galaxy, regardless of what it is [baryons or dark matter]. So we do not make up a fancy name for something mysterious. The mass is there. Using the spatial power spectrum of the cosmic microwave background we measure the ratio of the amount of dark [non-baryonic] matter and normal baryonic matter and find that there are 5 times as much of the former as of the latter. These findings are not made for the purpose of patching up some theory, they are observational facts.

NZ Willy

What you mean to say, Leif, is that the gravity is there — or its equivalent which bends the photons’ paths. We can conjecture mass as the originator — but it’s not ordinary mass, so it could be non-baryonic mass, or something else altogether. Maybe an extra dimension bends those paths. We don’t actually know the reason.

The simplest explanation and the one that fits the other evidence is that it is just ordinary mass, so we go with that. It is like when Neptune was discovered: something was gravitationally tugging at Uranus; one could dream up all kinds of unknown unknowns for that, but it turned out to be just ordinary attraction from a mass. When we observe stars wobble we conclude they have planets although we cannot see them.

NZ Willy

I agree with your analogy, but “dark matter” isn’t “ordinary mass”. It is new physics promulgated in 1998 — an “unknown unknown”, to use your phrase. We don’t actually disagree here — except that you think of “dark matter” as a form of matter. It’s unnecessary to be so specific. What is “matter” anyway? If it is “whatever makes gravity”, then you are right. If matter is defined as baryonic, then “dark matter” isn’t matter. Since it comes down to the term, we’re back to Feynman’s “wakalixes” of which he says “there’s no knowledge coming in. It’s just a word”.

Perhaps this will clear up your thinking
If something that mass it is matter. Try to kick a stone, the bigger the stone [more matter, more mass] the more your toe will hurt. ‘Matter’ is not just a word. Your toe will tell you.

But Leif, the gravitational anomaly observed in these instances is not being assumed to come from some sort of missing matter as we know of it, but of an entirely new form of matter that is otherwise undetectable and which had never been observed or even theorized to exist to explain any phenomena here on earth. When Uranus’ gravitational anomaly was observed, scientists did not have to theorize an entirely new form of matter to explain it, merely a previously undetected mass of ordinary matter – Neptune. So that analogy falls apart.
I suppose it’s fair to say that theorizing a wholly new and undetectable form of matter to explain the observed anomalies is marginally simpler than pinning the cause on some even weirder form of space-time twisting or a new form of electromagnetism, etc., but that depends on one’s point of view and subjective notions of what’s simpler. But that hardly makes it true and verified by the mere fact of the anomaly itself. Simpler exaplanations are not necessarily valid. A cosmic ether is much simpler than GR, but it happens to be false.

That dark matter has not been predicted to occur on or near the Earth is not really true. We have measured the density of dark matter in the solar system, and the 2nd bump in the CMB spatial spectrum was predicted more than 40 years ago, long before it was actually observed. And the analogy with Neptune holds. To be ‘matter’ it is not necessary to be baryonic, and Neptune was actually later observed [although nobody has held a piece of Neptune in his hand – which seems be your criterion for existence]. With the intense search going on for dark matter, it is only a question of time before we figure out what it is. There are already claims of detection, although most people in the business think the claims are premature.

Lief, as much as I respect your posts, please provide even a smidgeon of hard evidence regarding Dark Matter. The reason people reject this specific “hard evidence” is because there isn’t any. There is a lot of hand waving and Sherlock Holmes references, but belief in the prevailing Dark Matter thoughts is akin to religion, not science.
Have Fun!

Robert Boyd

Consensus is fine just as long as it is not promoted as if it was evidence. Evidence is the root of consensus not the converse.
And that is the problem.

Lsvalgaard, 9/18/14 @ 7:20 am: I have stressed again and again that the experimental evidence drives the consensus. The examples I gave are examples of the hard evidence it takes to convince scientists that there is a consensus.
Several aspects of science, missing in your mental model of science, are evident in these two lines.
(1) You can’t quantify any consensus, therefore it does not exist scientifically. A consensus among whom? Those who publish in compliant professional journals? The members of some professional society? The people who work on the same floor with you? The people who dutifully obey the positions of experts, their supervisors, or their editors? Assuming a consensus might be significant and hence interesting, then for any consensus one might actually quantify, who comprise 100%?
(2) The problem is not what drives a consensus, but what you suggest the consensus might drive. A consensus is not “hard evidence” to drive any model, no matter how the consensus was formed. No model exists in science which makes an appeal to a consensus. The best models, the one’s with scientists’ names attached, are those that break with a consensus, and indeed the journal narrative that goes with the model may feature what was heretofore the accepted model, flaws or not.
(3) Your “hard evidence” is undefined, beyond your implication that it is empirical. The “hard evidence” of science comprises facts that fit model predictions, where fit is measured in probability. Science doesn’t care what scientists or laymen feel or believe, or what it takes to convince them of any position with respect to a model. Those are the purview of Education and Psychology.

1) You can’t quantify any consensus
Of course I can. Just count the people
2) The problem is not what drives a consensus,
Consensus is driven by hard evidence. Consensus among experts is important for scientists that are not experts.
3) Your “hard evidence” is undefined
Hard evident is very well defined, namely as that which compels a consensus.

By including ‘expansion of the universe’, ‘dark matter’, and ‘fusion generating solar and stellar energy’, your definition of ‘hard evidence’ must include ad hoc mathematical assumptions.
A general consensus can be reached in science, because scientists may generally agree that a given theory is accurate. However, consensus cannot be simply injected into a theory as new evidence in favor of the theory.

I’ve worked on validating FDA processes – there is no consensus, it is either validated or it isn’t. Why can’t we have the same for something such as global warming science. Could it be that corruption, money and power are involved in the process?

The problem with the soft sciences is that they are not based on predictive value. They are based on explanatory value. Do they explain “why” something happens, then they are considered to have value, even though they have zero predictive skill.
This same approach has followed over into Climate Science, where positive examples are considered proof, without stopping to consider that you can find an infinite number of examples to prove something to be correct, no matter how wrong it is. What proves it wrong is the single false example..

The why of something has and always will pervade science. Quantum theory for example. The quantum mechanics were mostly figured out by Einstein’s late years and Quantum entanglement was described by theory through math that few still can completely grasp. And experiments confirm entanglement to the highest levels of achievable experimental verification today. But Einstein’s suspicion of quantum entanglement as “spooky action at a distance” still remains since it conflicts with General Relativity. The lesson is, Being able to describe a phenomenon should not be confused with understanding its deeper implications to understanding.
Thus we search today for deeper understandings of what controls Earth’s climate to provide a remarkably stable climate over at least 600 Mya since the last supposed snowball event. Biologists like myself are constantly amazed at the ever growing realization of the complexity of molecular events and layers of regulation that occurs in a living cell. Cellular life has been evolving into ever higher levels of feedback complexity for ~4Gya as an evolutionary response to maintain fitness.
But Earth’s climate system has been evolving shortly after the cometary bombardment era ended ~4.2Gya. The Earth has possibily evolved a very robust and complex set of layered feedbacks (that Venus or Mars never could attain) for early climate stabilization, and as solar output has slowly increased. That insight is the basis of the Gaia hypothesis. Now I don’t see Gaia as a living thing, in the sentient sense of life, but the complexities of all the air, ocean, CO2, bio-geotransforming geology, tectonics, geo-weathering of uplifted rock over hundreds of millions of years, means that even despite the hard perturbing impulses of bolid impacts, vulcanism, continent rearrangements, and orbital insolation variations, means likely Earth can take a lickin and keep on tickin’. Although we like to consider ourselves as having dominion over the Earth, Man’s CO2 pulse is but a whisper in Gaia’s ear. And we live in a nice quiet galactic neighborhood, a unitary stable star, and a most fortunate planetary arrangement whereby Jupiter is our playground big brother.

Because science is done by people and it takes people to interpret data. The popularity of this web site makes it pretty clear that different people interpret the same data differently. We don’t have a god or a computer that can do it for us. So we often rely on the development of agreement or consensus. Additionally, there are thousands of independent tests for the climate change hypothesis, i.e., it isn’t a single yes/no test. People are required to synthesis and integrate data from many different fields. Then there is the matter to degree…

I find that ArsTechnica, using a favourite term of Bible scholar R. M. Price, is a “stuck-in-the-middle-with-you” site. The consensus is always a result of patient, deliberate refinement of ideas and theories. The only “known unknowns” are those which can only refine the consensus and never overthrow it. Yes, you can question the consensus, but only where the consensus says you can, and only with its gracious permission.
Needless to say, the consensus always has a double standard. Agree with it and you are rational, enlightened and good. Disagree with it and what qualifications you have will never be enough, and what qualifications you don’t have will be the only reason why you are wrong.
The site also has an article called, ‘Is there a creativity deficit in science?’:
The irony is probably lost on them.

There is no creativity deficit in “Climate Science” for sure. Imagination abounds over there.

Thanks! I know your meant that as a criticism but it does a lot of creativity to be a scientist. And I know few people as creative (or talented) as John Cook.

One gets the reputation one deserves . I have always been struck by the fact that historically the consensus has usually been wrong. Once again I’ve been struck.

in point of fact, it is hard to find examples from history where the consensus has ultimately been proven correct. About the only thing you can say for sure about a consensus is that it is almost certainly wrong, and will be proven to be so in the fullness of time.

Social consensus about ideas, sure, we are often wrong, have always been, will always be. But it isn’t all that common that broad consensus in modern science is wrong, in part because it is pretty rare. A few examples of very strong consensus about major theories are plate tectonics, evolution by natural selection, the germ theory of disease, and the coding of the phenotypes of organisms by DNA. That said, I agree in narrow subfields of science, people (being people) do convince themselves of ideas that are pretty clearly falsified.

John Bruno says:
Consensus is pretty rare, and a few examples of very strong consensus about major theories are:
Am I misunderstanding? It’s not clear. But all those are examples of the consensus being overturned, not examples of the consensus being correct.
I have no doubt whatever that the consensus supporting catastrophic AGW will turn out to be just as misguided and wrong.

George Morrison

So, dbstealey
You’re suggesting that AGW is like the old theories of static continents, creationism, deity-imposed disease, earth-centric universe? And the new evidence-based-overthrowing-paradigm is along the lines of “To everything, turn, turn, turn. There is a season, turn, turn, turn.”???
Carry on. Seriously, carry on. Clown.

disease, earth-centric universe?

* * * * * * * * *
dbStealey is being too kind on AGW. Anthropic Global Warming should be compared to the Witch Mania.
Witches are so called on account of the blackness of their guilt, that is to say, their deeds are more evil than those of any other malefactors.They stir up and confound the elements by the aid of the devil, and arouse terrible hailstorms and tempests.”
There are also natural harms which in some manner depend upon the conjunction of heavenly bodies, such as dearth, drought, tempests, and similar effects of nature.”
Malleus Maleficarum, part 1, question 2 (1486)
George, you gullible clown: How much of the global non-warming of the past 17 years do you attribute to human activities, and how much do you attribute to “nature”?
What’s your favorite peer-reviewed excuse for “the pause”?

Problem with consensus…is why there had to be a consensus in the first place
Obviously the science doesn’t hold up, or there wouldn’t be one….
…people form a consensus because they have too much invested in something…for it to be wrong
It’s very hard to disprove a consensus…..obviously, because there was no proof in the first place

Lat, consensus is derived from the lack of confidence, and justification of such, in a position, and a fundamental desire for company/support in such matter. Hierarchical scale in the psychological department if you will in the end.
In science, I refer to it as the Lemming principle. There is a definitive positive feedback when funding “income” is involved… The paritipants adapt and follow, for good reason.
Insert “Jerry Maguire” show me the money video here.

David L. Hagen

Needed: Independent Verification and Validation
Since it “only takes 1”, when will Congress loose NAZA’s Independent Verification and Validation Facility onto global climate models?

Welcome to NASA’s Independent Verification and Validation (IV&V) Facility, home of NASA’s IV&V Program. Located in the heart of West Virginia’s emerging technology sector, NASA’s IV&V Program was established in 1993 as part of an Agency-wide strategy to provide the highest achievable levels of safety and cost-effectiveness for mission critical software. NASA’s IV&V Program was founded under the NASA Office of Safety and Mission Assurance (OSMA) as a direct result of recommendations made by the National Research Council (NRC) and the Report of the Presidential Commission on the Space Shuttle Challenger Accident.

The Right Climate Stuff provides initial V&V efforts on IPCC and finds its models lacking.

Willis Eschenbach

The lack of V&V of the models which are being used to justify billion-dollar climate decisions is scandalous.

W. Agree. The longer this goes the more clear it becomes that it was never about climate science, or even the weather equivalent of engineering. (Although hats off to the National Hurricane Center in Miami. Keep narrowing that cone of uncertainty.)
Sort of fun to watch the wheels come off the bandwagon.

Bill Illis

What is the consensus then?
– Is it CO2 is a greenhouse gas?
– Is it CO2 will produce a warming planet?
– Is it Man’s additional CO2 has increased temperature by 0.5C and 0.25C is natural?
– Is it that increased CO2 will result in +3.25C by 2100?
– Man is ruining the environment.
– 48 other statements.
How can there be a consensus when nobody knows what the consensus is?
What is recorded in the Minutes of the meeting as the consensus?

Come now Bill, the consensus has been repeated many times and is very simple: “Man is responsible for some of the warming of the climate in the last century.” It is very simple and unassailable. It is impossible to refute.

David in Cal

Right, but the climate hucksters encourage a misstatement of what the consensus actually is. President Obama, among others, was fooled into believing that the consensus said more than it actually does. Note that the consensus says nothing about man having a big impact or about climate change being harmful.

Don’t forget the second and most important part: “And therefore government policies and laws globally restricting access to and increasing the cost to consumers of and tax revenue associated with energy must be adopted, with exceptions for those employed with state and parastatal organizations.”

Pat Frank

It’s easy to refute, Dan. Just calculate the physical uncertainty intervals for climate model projections. They’re off the page.
No one can say that any of the warming is caused by humans. No one can say that none of it has been caused by humans, either. The science cannot support any definitive statements in any direction.
No one in the AGW camp, in short, knows what they’re talking about. And no one at all anywhere knows enough to say anything quantitative about the effect, or not, of small changes in GHGs upon the climate.

Ian Schumacher

It’s not impossible to refute … quite possible man isn’t responsible for any warming since the very small amount of warming we have had so far is well within past natural variation changes seen in that past (that occurred without any influence from man what-so-ever). It’s my opinion that man ‘probably’ has had an effect, but it’s far to strong to say “impossible to refute”. Way way too strong.

Pat and Ian, It is IMPOSSIBLE to refute. Saying we do not know for sure how much man is contributing is not refuting it. There are obvious examples of where man affects local climate such as Urban Heat Islands where cities can be 10 degrees warmer and there are examples of man contributing to the expansion of deserts. To claim these local climate changes have absolutely zero affect on global climate is not logical. It may indeed be very small but it will not be zero.

Pat Frank

Dan, your “impossible to refute” is identical to total lack of knowledge. It’s equally IMPOSSIBLE to refute that invisible pink unicorns dance on my lawn every Easter. But so what? Will you put out bowls of milk for them, anyway?
There’s zero evidence that AGW is happening, that humans have had any effect on global climate, or that anything unusual is going on with weather. What steps are rationally warranted in response to zero evidence?

Mike O

The problem with consensus is that it can never be proven wrong. Any direct observation to the contrary must not be correct because the consensus believes otherwise.

As explained below, it certainly can be proven wrong (or overturned) but that isn’t the right way to think about it. It isn’t a hypothesis. It is really more of a straw poll about how scientists in a field have interpreted the available evidence.

John Bruno:
Please define the “consensus” in climate science.
Be precise.

Jim Clarke

Talk of consensus in climate change science is a really misleading, because there isn’t one and never has been. Oh…I guess there is consensus that CO2 is a greenhouse gas, and if increased while all else is held equal, will produce some warming, but that is it, and that is nothing. There is no consensus on any other relevant aspect of climate change! It’s a myth, pure and simple.
So writing essays on the importance (or not) of consensus in science, with climate change as the backdrop, is completely off base. It lends to the fallacy that something significant has been agreed upon by the vast majority of relevant and capable scientists in the field of climate change. There is no such agreement.
Whenever the word ‘consensus’ comes up in a discussion of climate change, I simply point out that there is no consensus on anything important. If they disagree, I simply ask them to tell me what it is. That usually ends the conversation in my favor.

Jim, your comments prove your point. That there is a consensus about climate change is a demonstrable fact. You may disagree with it and it may be wrong, but your hypothesis that there is no such agreement is easily refuted.

D.J. Hawkins

Oh, goody! Please provide a bullet list, since you are one of the gnostic few.

Jim Clarke

John, my comment was that there is no consensus on anything important. There is no consensus on anything that makes AGW more than a scientific curiosity. The consensus that does exist is trivial in a social/environmental context. The consensus that does exist is meaningless in policy discussions.
Its like having a consensus that ‘water is vital for life’ as the basis for a discussion of a flooding problem. Sure, everyone agrees with the statement, but it is completely irrelevant to the matter at hand.
Activists are passing off the trivial consensus that CO2 us a greenhouse gas as equivalent to a consensus that CO2 emissions are equivalent to a major calamity facing all of humanity, and that is simply a lie.
Here’s another analogy: Everyone agrees that clean oil in your car engine is a good thing, so your mechanic uses that ‘consensus’ to argue that you must come in and have your oil and filter changed every morning or your engine could lock up while you are rushing a pregnant woman to the hospital and the baby will die. Then he asks if you want a dead baby in your car or will you do what he says. Finally, if you don’t agree, he calls his friend the police officer, who agrees to point a gun at your head each morning until you go get your oil changed; all based on the irrelevant consensus that clean oil is good for your car engine. Would you support the actions of your mechanic based on such a consensus, or would you rationally point out that the consensus doesn’t support his arguments at all, and is therefore irrelevant?
The scientific consensus on CO2 is irrelevant to the ISSUE of CO2, yet is practically the only argument activists have to fallaciously support the notion that we face a climate change crisis.

Alright, the debate is over, the issue is settled, we’ve taken the poll and consensus has been reached.
It is obvious the GPS on all three brands of smartphones cannot be wrong, so we are taking this bus around the “Road Closed” sign and through this thick fog across the bridge we know is there to the climate science conference. Any dissenters believing that false news alert can get off now and go home, we don’t want your kind at our conference.

Joel Grey, Lisa Minnelli – “Money, Money” number in Cabaret. Excellent!

Leon Brozyna

In science, if the talk is of consensus, then you’ve got neither.
In science, if there’s agreement on a theory, it’ll hold until there’s a better theory. Agreement does not equal consensus; it just means you haven’t come up with a better theory.

Actually in the context under discussion here, agreement and consensus mean the same thing. What is meant by “the climate change consensus” is simply that there is overwhelming evidence that greenhouse gas emissions are warming the plant. A large majority of scientists believe that. Some obviously are not persuaded by the evidence, but they are in a very small minority. I agree that doesn’t necessarily mean they are wrong.
The consensus isn’t testable or refutable because it isn’t a scientific theory. It is simply a quantitative approximation of whether the scientists in a given field believe the balance of the evidence supports a theory. It is the theory that is testable and falsifiable. And it is plausible that new evidence could come along a overturn the theory of anthropogenic climate change. Unlikely given the massive weight of the evidence but possible. Ill try to respond to a few other commenters to explain what agreement and consensus are in science.

John Bruno says:
They are also warming the ‘planet’. But that is not nearly enough of an answer. The real question is: HOW MUCH are they warming the planet?
To date, there is no empirical, testable evidence measuring the fraction of a degree of global warming [out of the total of about 0.7ºC of global warming] that is attributable to human CO2 emissions.
Does Mr. Bruno understand that? There is NO such scientific evidence. No measurements have been made that quantify the degree of warming specifically due to human emissions. There is always an unverifiable assumption that human emission cause warming. But there is no empirical, measured evidence.
Since there are no such empirical measurements showing just how much global warming is due to human emissions, the AGW claim is nothing more than a conjecture; an opinion. Science is nothing without measurements.
However, there are empirical measurements showing that changes in atmospheric CO2 are caused by changes in global temperature. Again, there are no such measurements showing that changes in CO2 are the cause of changes in temperature.
So, what is that vague, nebulous “consensus”? And why is it directly contradicted by real world measurements? If the climate alarmist crowd cannot answer that question, and if they cannot show specific measurements quantifying the amount of global warming due to human activity, then why should anyone pay any attention to them?

Steve Reddish

John, I don’t think anyone has an objection to the concept that a majority of scientists might judge that a particular theory is confirmed by the evidence at hand. The objection is raised when those in support of a theory try to suppress those who wish to present evidence contrary to that theory, using the justification that “disbelievers” are defying the consensus. Blocking contrary evidence becomes particularly heinous when both the evidence supporting the theory, and the evidence supporting the claimed consensus, are discovered to have been falsified.

Pat Frank

There is zero evidence that GHG emissions are warming the planet, John. The reason there is zero evidence is that climate models do not have the resolution to reveal the climatological effect of small changes in GHGs.
Look in the literature. There are no physically valid, accuracy-revealing error bars on any climate model hindcasts or forecasts. At best, you get inter-model variance — model precision. Precision reveals nothing about accuracy.
Climate model accuracy-reflecting error bars are huge. Models are therefore non-predictive and non-explanatory. They cannot resolve the effect of GHG emissions, and cannot reveal their effect, if any. That means zero evidence.
Copious data posted here at WUWT have shown over and over that nothing in the climate observables — storms (type, intensity, frequency), droughts, floods, winters, summers, or whatevers, reveal anything historically unusual in the dynamics of the modern climate.
Nothing resolvable from theory, nothing observable in fact: where’s the “overwhelming evidence”?

The “overwhelming evidence” is the problem part. What evidence? There is consensus that the planet is warmer than it was during the LIA. Analyzing the available temperature data from that span tells us nothing at all about the cause of the warming – nothing. There is also quite sound evidence from ice-core data that we could predict that as the planet warmed, atmospheric GHG content must increase and even forecast the timing of the increases. That is simple physics and causality points from temperature increase TO GHGs increase, not the other way ’round.
The AGW hypothesis demands a rejection of Occam’s Razor to assert that warming in the last 50 years is somehow different than warming in the preceding 150. If you read the Climategate material, it is quite plain that the “Team” considered the available empirical record to be the biggest stumbling block to a beautiful theory. Otherwiuse there would no discussions concerning how to get rid of Medieval Warm Period. The authors did not show concern regarding the LIA because the warming following it was consistent with their hypothesis. But the LIA is quite as much a problem from a theoretical view point as the MWP was.

There is really no need for “97% consensus” to prove that global temperatures have been slowly rising since the last ice age, or that greenhouse gases and aerosols in the Earth’s atmosphere have raised surface temperatures above the expected black-body termperature. The temperature record and the known laws of physics are sufficient to prove (or disprove) this.
But, so far, there has been no compelling proof that manmade CO2 has caused or will cause the climate ‘catastrophes’ we read about everyday. So the “97% consensus” is desperately needed as a “proxy” for the missing “compelling proof”.
What’s that you say? ‘Every climate disaster reported by the MSM is a compelling proof of CAGW’?
No. That’s proactive journalism, not science. Like a self-feeding frenzy of shark-bite reports.
“If you believe that elves make the rain, every time it rains you will see proof of elves.”
If you are taught that manmade CO2 causes catastrophes, then every climate disaster will seem like proof of CAGW.

If I am not mistaken, average global temperature has been decreasing since the end of the Holocene Climactic Optimum about 3500 BCE.

George Morrison

You are correct, sir!

The global temperature since the last ice age has had its “ups and downs”, but overall it has risen since 12,000 years ago, a proposition of great certainty, which needs no ‘consensus’ to prop it up. That was the simple point I was trying to make.
The “devil is in the details”, of course, and so a very detailed temperature record, correctly accounting for all of the ‘optimums’, is much less certain, and subject to much controversey, as we all know too well.

“Climactic” ?

September 9, 2014 at 5:40 pm

This is an “end point” fallacy. Depending upon the chosen end points in a time series you can show trends in any direction. In this case you also jump from one geological period to the next with acknowledging the transition. The sole reason for the historical separation of the Holocene from the Pleistocene was that it was clearly warmer in the Holocene. Within the Holocene period, the temperature trend has been a level to cooling one, not a warming one.

Ok, I guess I didn’t pick a clear example to make my point. We’ve been warming since the last ice age, but cooling since the optimum in 3500BP. It would have been more clear if I had said that we’ve been warming since the LIA. Thanks for your comment.

in 3500BP since 5500BP

The fact that a large number of scientists have felt and still feel the need to research whether or not there is a consensus on the concepts of AGW indicates the matter is questionable.
In my opinion they are premature in trying to reach a conclusion.

In Science it doesn’t matter who present an argument/a thesis or how many scholars/experts supports the same. Authority is no safe criterion of credibility. It only takes one proving the Authority/group of “experts” wrong to falsify a thesis. Thus the number of scholars/scientists/experts arguing for a thesis is of no value at all.
While it’s possible in Mathematic Science to prove for example Fermat’s Last Theorem (proof presented 1994) that’s an exception in Theories of Science. Over all a thesis can’t be proven right only be proven wrong. For each argument presented it takes a close analyse to find all needed premises for the argument to be considered “true”/valid/sound. If one single part of the needed premisis doesn’t “hold water”, the argument is to be considered non-valid.

Owen in GA

Very true. Most of the basics of Mathematics were proven to support some observation in Physics. The mathematical proof was needed to show how to get a reliable prediction out of the physical theory.
Now the mathematicians do sometimes lead the scientists by exploring some “nonsense” space and driving through the theory to its proof, and only later does some physicist looking through the mathematics literature see that this “nonsense” space is actually some phase space projection of a problem they are trying unsuccessfully to solve.
But again, science comes down to how to calculate a future state with enough specificity to be able to place instruments to record the event and compare. This is repeated with different elements of the prediction until the theory fails (ie prediction does not match measurement) or the researchers run out of imagination on ways to test the prediction.
That doesn’t mean that 50 years from now some other researcher will devise a test that shows the theory fails, human ingenuity is a very individual thing after all.

Owen in GA

I also need to learn how to hit two enter keys between paragraphs or start using < p > tags.
[Reply: Yes, please. In the mean time, single paragraph broken down. ~mod.]

That’s not quite right. Mathematical theories (“theorems”) are not the same as scientific theories.
The correctness of a mathematical theorem, given a set of axioms and definitions, can be proven or disproven absolutely (i.e. proven fully or not at all). There are no “half-proofs” in mathematics. So there are “proof systems” that use rules to validate theorems from axioms. Also, proofs of mathemetical proposistions can be obtained by building “models”, such as truth tables.
But no such absolute proofs exist for making predictions about real-world phenomenology. We can build theories based on observation, and test them against existing data, or make predictions, then wait for them to come true (or not). But there are no absolute guarantees that a theory that has been making successful predictions (e.g. “The Sun will rise again tomorrow”), will continue hold in the future. (In mathematics, such guarantees are absolute, given a set of definitions and axioms.)
In science the best we can do is assign confidence values to our favorite theories, and perform diligently to gather data and run experiments to prove or disprove them (if we are honest).
So, some science theories generate very high confidence (“The Sun will rise again”). Others (“CAGW”:) have little confidence or none.

Not true. You might use Chebychev or any other known theory for your confidence value. That doesn’t prove your confidence value to be true.
Please go back to basic Mathematic Statistic theories. For those who never studied or never understood I suggest Huff, How to lie with statistic all published so called science by scholars/experts believing in CO2 to be a threat have used fallacies more than once in their studies.
Only the scholars studying the sun have up to today presented papers that’s sound science using mathematic. I am not agreeing with their conclusions every time, but that’s an other thing as long as neither I nor anyone else proven their thesis wrong.

> Not true. blah blah blah
Looking at your response below [there’s no ‘reply’ button on your post]. I can’t see which of my statements you think is ‘not true’.
The rest of your response is Babble. I suspect that you are either 1) an mischievous troll 2) or computer-generated nonsense. Good luck with assigning confidence values to math theorems. That will definitely improve the rigor of mathematics. Maybe.
In either case, you have failed the Turing test. No sign of intelligent life here, we’re moving on.

“Consensus” is a serious problem for science. The scientific method provides a system where an individual who is right can formally challenge the many who are wrong. Consensus works against this.
The human being is an animal, a mammal, a primate. We are a social animal and our basic social structure is tribal and hierarchical. This leads to a dichotomy between our base instincts to tribal conformity and the intelligence of the individual. The scientific method has provided a system to minimise the problems associated with this dichotomy in the modern technological age. “post normal” pseudo science and the “climate consensus” have seriously compromised this.
As sceptics, some readers may be fooled into thinking that the tribal urge to consensus does not effect them. It effects most of you too. Allow me to demonstrate –
I say –
”Global warming due to human emissions of radiative gases is a physical impossibility. 71% of the planets surface is ocean, a “selective surface” with radiation absorbed at depth and emissivity asymmetric with absorptivity, not as the 97% claim an near blackbody with emissivity and absorptivity close to unity. This means that without atmospheric cooling, regardless of DWLWIR, the sun alone could heat the oceans to 80C or beyond. The net effect of our radiative atmosphere over the oceans is cooling.”
You think –
“That can’t be right”
But why?
Because a lot of people say otherwise?
Have you personally checked the the difference in apparent emissivity of water under different background IR levels? Probably not.
Have you personally checked whether incident LWIR slows the cooling rate of water that is free to evaporatively cool? I’m guessing not.
Have you personally checked what change differing depth of SW absorption makes to the equilibrium temperature of transparent materials? Not likely.
It is far less challenging to run back to the safety of the “sceptic consensus”. “CO2 is a “greenhouse gas” that should cause some warming but is being offset by negative feedbacks”. Back to the safety of the tribe.
Now you know why the alarmists push the “consensus” propaganda so hard. It works. Even on most sceptics.

The Skeptic

It’s so great to know that the consensus is always right when it comes to science.
So here we are, on our beautiful little flat planet, with the sun, moon, and stars all revolving around us, unable to fly, let alone break the sound barrier…

I have a problem with this part of the essay:

When asked about this book, Einstein retorted with this:

Surely simply finding three naysayers or even one naysayer isn’t enough to disprove Einstein. They have to put forth some sort of an argument proving him wrong. I doubt your 3 out of 100 could disprove climate science, because I don’t believe it is any more disprovable than God.

> I have a problem with this part of the essay: …
>” If I were wrong, then one would have been enough! …
What Einstein is saying is that valid scientific theories are “falsifiable”. So, if one of his theories makes an incorrect prediction, it would take only one person to observe and report this. Thus falsifying the theory.
So there were hundreds of papers written in the 1930’s, but none of them were able to make any observations or conduct any experiment that falsified Relativity. It would only take one such observation or experiment to “ruin” Einstein’s theory. But none were found.
That doesn’t mean Einstein’s theory was therefore “proved”. It just means it has not been falsified. Yet.
But, in religion, most of the important propositions (existence of God, Heaven and Hell etc) cannot be directly observed, therefore cannot be falsified. Therefore it is a belief system, beyond science.

You put the burden of proof on the wrong people. What the climate alarmists are saying is that something is happening now that has never happened in the past. That is the extraordinary claim, and that extraordinary claim is what must be proved by evidence. There isn’t any evidence that support the idea of a catastrophe due to global warming.

Climate “science” is easy to disprove, by anyone. Just follow these two simple steps:
1. Examine prediction.
2. Compare prediction with observation.
97% of “climate science” = disproved. It’s easy.

You really mangled the Einstein quote, so I’ll take the rest of your comment with a lump of salt.
“Consensus” stops at the very first step of the Scientific Mehtod. It is a conjecture, nothing more. Conjectures are akin to opinions. A consensus is an opinion.
After conjecture comes hypothesis. To be accepted by scientists, a hypothesis must be able to make repeated, accurate predictions. AGW cannot do that. Despite many $millions spent on GCMs [computer climate models], not one of them was able to predict the most significant event of the past twenty years: the fact that global warming has stopped.
Therefore, both the models and the entire ‘consensus’ are demoted to the status of a conjecture. They failed the most basic test of a hypothesis: they cannot accurately predict anything.
Finally, it does not take “three naysayers” as you so pompously phrase it. All it takes to falsify a conjecture or hypothesis is one fact.
There are numerous facts that falsify that conjecture. Einstein would have a field day with it.

What those appealing to the authority of the consensus of opinion seem to miss.
Is just that, It is Opinion.
This group hug would be unnecessary if they actually had some science to share with those who question their opinion.
Climatology AKA Climate Science is an oddity, somehow in this bizarre world, opinion is the evidence.
Data is not welcome.

I dont miss that. It is just opinion.

George Morrison

[snip – taunting rant from “rustneversleeps” who has been banned here -mod]

4 eyes

And I want to know exactly what is agreed upon in this consensus. dbstealey asked above and I can’t see an answer. I certainly wouldn’t say I agree with something that I could not accurately describe. Just tell me what the consensus is and I will go away.

Since they mention Michael Crichton, here is another quote from him.
Joe D’Aleo uses this in his article “Data Games” currently on
The source is:
“Environmentalism as Religion”

Einstein’s comment ignores whether one or more of the papers in the collection were right.
If he were a Climate Scientist I would have to say it was an excellent propaganda statement.

Paul in Sweden

If a ‘Climate Expert’ can and has meant simply a psychologist that can recite the mantra of the global warming industry; what value is a consensus of such ‘experts’.
<Distribution for Endorsements —
possible for endorsements. I think the only thing that counts is
different story.
Conclusion — Forget the screening, forget asking

Paul in Sweden,
That is a damning Climategate email!
The OISM Petition actually got the names of more than 31,000 professionals with degrees in the hard sciences, including more than 9,000 PhD’s. That email appears to be an alarmist attempt to fabricate something to compete with it.
But they could never get legitimate names, like the OISM Petition did. OISM was very straightforward: CO2 is harmless, and it is beneficial to the biosphere. More than 32,000 scientists and engineers co-signed that statement, which is the true “consensus”. No alarmist petition has come anywhere close to the OISM’s numbers.

The number of people in the USA that qualify to sign the OISM Petition numbers about 2.6 million.
30,000 / 2,600,000 = 0.01154 less than 1.2% of the people qualified to sign.
So, 98.8% of the people qualified to sign the OISM Petition have not done so.,
Now apply your same numbers to the climate alarmist clique.
See? By any measure, the OISM Petition represents the true “consensus”. They have far more legitimate signatures than any alarmist petition was able to get:
The alarmist contingent tried to get ‘apparent’ support going into Kyoto. They failed, but not before trying to unethically game the system:
possible for endorsements. I think the only thing that counts is
[source, Climategate emails]
Well, OISM checked. They vetted every signature they got, and they got more than 9,000 PhD’s — all of them with degrees in the hard sciences. So even by cheating, the alarmist crowd could not come anywhere near the OISM’s numbers.
Better run along back to whatever alarmist blog you got your misinformation from. You need some new talking points.

Ian Schumacher

I only read the first part, but from my reading of science history that first part is true. Einstein did not create special relativity ‘from nothing’. There were already several papers on it. Why his paper got ahead and the other didn’t, who knows. Was his summary more clear, more complete? Did he add something that made everything fit better? Was the scientific communities collective consciousness simply ‘ready for it’ when he published. I don’t know the details, but I kind of suspect the last one.
Still he went on to show that this was not a fluke and I don’t think any one can dispute that later on he really did break new ground.

Great book!

I agree with Einstein, in physics, it’s unimportant. In climate science, which is backwards and in deep trouble, it is important. That should worry all of us. I dont mean to imply there is no trouble in physics, and a good part of that trouble comes from the misunderstanding of Einstein. Einstein in 1905, was not the Einstein of 1920.
But the media needed an icon as did the physics establishment and that icon is a big problem in physics.
Much of post quantum physics is happening online these days and when someone says something ‘not even wrong’ it will get piled on, but elsewise, argument rules and not consensus!

consensus said the sun rotated around the earth, people were eventually willing to learn and admit they were wrong.
don’t expect the warmers to ever admit that due to funding.

Argue in general about consensus all you want here, the important thing is that a consensus was found from 12,000 scientific papers AND IT IS TRIVIAL and MEANINGLESS to the debate BUT the claim of consensus has been morphed into something it is not.
It’s typical re-re-re definitions of terms that is purely political.
I think it’s more useful to accept the ‘consensus’ and every time it’s brought up to show what IT ACTUALLY IS rather than to go off on tangents about the general validity of any consensus, what the scientific method is, the number of papers ‘refuting’ climate change, etc.
The latter just makes non-skeptics eyes glaze over, the former hits them squarely between them. Focus, people, focus.
Make sure that hits home first, then carry on with everything else.

Ian Schumacher

It is bait and switch for sure. Get consensus on what almost everyone agrees is ‘likely’ and then pretend you have a consensus on something completely different.

Gary Pearse

Almost all here has ‘consensus’ wrong. By its nature, a consensus on something scientific means there is considerable uncertainty. If it is a dead certainty (the earth goes around the sun), a consensus on it (a show of hands) is meaningless. Now in a complex political situation, where there is no way of knowing whether such and such is the best course of action, or best strategy, it is argued, and there is give and take, compromise, and finally they arrive at what individuals can live with as a course of action, even if not any of them are fully satisfied by it. Yes, the irony of all this talk about consensus is that it means the best they can come up with under the circumstances. Probably among the team, they are close to unanimous on the science – 97% probably. The climategate emails showed the creation of the consensus. Hey they punished those (and still do) who step out of line. They had a consensus on what to do if a journal published a paper not certified by the synod, for example or what to do if one of the unchosen asked for data.

Owen in GA

But the Earth-Sun System actually both orbit their mutual gravitational center. Flatly the Earth does not orbit the Sun, but the center of mass of the system, as does the sun. The fact that the sun is so much more massive that the center of mass is inside the sun (but not its center) is of little relevance So the consensus you propose would be wrong. (OK, they actually both orbit the center of mass of all the objects in the solar system, which wobbles around due to the various orbits, but is always inside the sun’s volume.)
See what consensus gets you–there are always skeptics and heretics.

Exactly the point Salby makes in his talk in the UK.

John Of Cloverdale WA, Australia

Peer Review: You scratch my back and I’ll scratch yours.

I pick Einstein over Mann every time.

Ian Schumacher

It just occurred to me that the ‘CAGW’ team is full of nothing but mediocrity, while the ‘skeptic’ team has several super stars on it’s side. Let’s see Hansen, Mann, Schmidt, Santer, Romm – mediocre science all the way down. I can’t think of a single ‘superstar’ scientist on the CAGW side (that is actually know for their outstanding ‘science’ not their political activism) That versus Freeman Dyson, Richard Lindzen, Nils-Axel Mörner, William M. Gray, Henrik Svensmark, Christian Schlüchter and many other *leading* experts in their field.

The further “climate science” advances, the more it is apparent how little they really know of what is really out there.
“Consensus” is a group of self-accredited climate experts huddling together in the cold forest in the dark of night, seeking safety in numbers from the marauding Zombies of Denial and ever-prowling Koch Conservative Werewolves, as they eagerly take turns warming their hands with the thermal emissions from a single carbon-neutral solar panel.

Ben Of Houston

It’s a bait and switch argument. Consensus about methods or standards is very different than consensus about conclusions.
If the consensus is that it takes 5 sigma difference to prove X, and my data shows only 2.5 sigma, then my data is rejected. I can get better data or better measurement and increase my confidence to gain acceptance.
However, if the consensus is that the world is warming catastrophically, and data shows that it is not, then consensus cannot be used to refute the fact that it is not catastrophically warming. Refutation must be done with facts

In my opinion, what we have here is some confusion between what a consensus is and what is happening in climate science. As Leif said, consensus has enormous meaning in science. The confusion here is that what we see in the field of climate science is not a consensus. It is a determined effort by a small number of activists to create the perception of a consensus. This is an entirely different matter from having an actual consensus.

Dave Worley

Yes, there has to be something specific upon which to base a consensus. Where is a theory published upon which a consensus is in agreement? If the same theory were referenced in a preponderance of climate papers, then we might have a basis for consensus.
For the time being, what they agree upon is vapor. They are all over the map!

There appears to be a consensus on the consensus of consensus on this site; and no consensus on the consensus. (I don’t know what it means either – thanks Gary P.) How do think tanks that outperform computerized results reach a “decision”? Where is the pea?
Of topic slightly, but read the “Alchemy of Air” on how science gets perverted. Nothing new.

Wow – just wow.
So you’re saying the big oil money has swayed the Right away from your consensus.
You do realize that’s a load of crap, right? I mean, BILLIONS of dollars spent manipulating journals, media outlets, end the education system vs. what, $200k spent by “Big Oil” against the consensus?
Looks to me like it’s a question of common sense and reality vs. an absolutely ridiculous and easily debunked LONG since disproved hypothesis… but one that won’t die. There is no “science” about this, since the “science” is completely AGAINST the “consensus”. It’s only about politics, power and money. Only.

Alan McIntire

As to actual scientific issues, like evolution, the expansion of the universe, fusion in stars producing most of the elements in existence, consensuses arise naturally. Those facts don’t directly affect our lifestyles or politics.
Global warming, as an abstraction, wouldn’t affect us either, but when people use those issues to argue for forced lifestyle changes and political action, the subject is no longer science but politics.

Doug Proctor

The consensus issue is a real headscratcher when there is no dispute that the last 15 years of temps has not followed almost all of the modeled profiles. The narrative only holds if you say the next 15 years will counter the last 15 so-as to bring the 30-year average into IPCC agreement.
CAGW exists only in the extremes. Somehow this part of the story has become disconnected from the observations to-date. There is no part of the narrative that says extreme weather happens under the current temp rise, yet every strong weather event is said to be CO2 related.
What we have to have is a quick temp drop. I sense the eco-green is worried that this will happen in the next 18 months, before some Green treaty can be nailed down.

I think we have a consensus that we all disagree here!

[trimmed. Again. Stop it. .mod]

Consensus is only a problem when it is used (or misused) to trump facts.

The alarmist crowd refuses to define “consensus”. It means as many different things to them as an elephant does to six blind men. What the alarmist crowd wants to explain to skeptics is: “Shut up!”
“Consensus” is simply a bludgeon used to shout down scientific skeptics — who have the alarmists on the ropes. It is deliberately vague. Because if they specifically defined ‘consensus’, it would be promptly deconstructed for the nonsense it is.

Thats the winning definition:
Because, shut up!

I have a rule for life, “Don’t believe everything you know”. In other words don’t be closed to new ideas, information, proof, evidence, and even truth. Most of what science has known over the entire span of recorded history was later proved untrue or incomplete, though most of those ideas were accepted by the consensus. That being true, it would be incredibly arrogant indeed to think that everything we know right now is true. How is it possible that somehow, right at this moment, everything we know is true? That is very improbable statistically. I submit that there is nothing special about this moment in time, and that most of what we know is also untrue or incomplete. Therefore, “don’t believe everything you know” because that will close your mind to new information, ideas, and truth. Consensus means nothing to me except as a measure of the popularity of a certain theory.

Willis Eschenbach

Consensus on what? For example:
Most informed climate scientists think that the world has been warming slowly, in fits and starts, since the Little Ice Age a few centuries ago. So there is consensus on that.
On the other hand, there is very little consensus as to just WHY the world has been warming slowly, in fits and starts, since the Little Ice Age a few centuries ago.
In other words, claiming that there is a “consensus on climate change” is meaningless without detailed specifications.
The most unfortunate and in my opinion most incorrect consensus is the idea that the global temperature is a linear function of the forcing. Even skeptics believe in that sleight of hand … which is why I describe myself as a heretic rather than a skeptic. I hold that the temperature of the earth is maintained by a host of emergent thermoregulatory phenomena … and while to date I’m only part of a small consensus of the select far-seeing few, I have my hopes …

Ian Schumacher

Thermoregulatory? The ‘regulation’ only seems to work at top where climate is astonishingly stable. It’s fine with letting us fall into an abyss of cold though. Otherwise of course I agree. One only has to look at the (apparently) ‘open system’ during ice ages where temperatures fly around wildly to appreciate the narrow well-regulated band at the top where they hardly move at all (implying an obviously very strong negative feedback).

A good point Willis, there are many consensi (consensuses?). About the only thing that is agreed is that it warmed over the last 150 years and a totally unconnected assertion that CO2 in a closed unchaotic test tube can cause warming? The connection between these assertions are speculative at best.
Personally I agree that there are clearly non linear saturation effects operating in the climate, cloud and thunderstorm emergence being two of them. Whether they play a limiting role on the climate – well that is the question isn’t it.
On the consensus, I think the problem here in climate science is trying to assert that there is one, against the overwhelming evidence that there really isn’t one. Instead of admitting they ate all the cookies, the climate scientists have enlisted all their brothers and sisters in order to convince mummy that there are invisible cookies in the jar. The single biggest problem in climate science is that it’s staffed by environmentallist, aberrent personalities that desperstely want to “save the world” – that’s what attracted them to it, it’s science with a cause, science with passion, and that’s the failing – objectiveness has gone out the window and they are pointing at an empty cookie jar pretending that there are invisible cookies in there that noone except the annoited can see.
For example the oft repeated claim that the West Antarctic shelf is melting from climate change, an effect that would cost about 15W/m2 which is only 20 times the energy Hansen said was available from global warming (0.6W/m2). It may be melting, but on the energy numbers, it’s not from CO2 – invisible cookie, it might exist, but its definitely in someone elses jar.

ferd berple

it is a nonsense to suppose a dynamic system such as climate will respond linearly to forcings. what other natural system does? Are there any?
there is perhaps a case that the response will be near linear for very very small changes, simply because a very small increment in a non-linear system can be approximated using a linear function. But this doesn’t mean you can stick these small linear increments together and get a straight line.

Pamela Gray

In educational and social research (yeh, I know, taint science), consensus is nearly the only game in town. And it shifts. Is it slow to shift? You bet. Too slow for me? Yep. Too slow for parents? Yep. But the research results are not iron clad. There is no litmus test for educational outcomes or social interventions (and here I mean interventions related to social skills or interventions related to group think problems like the Jim Jones thing). So do we throw the baby out with the dirty water?
Consensus is a part of science and is abused. What part of that surprises anyone? At issue here is the idea that one bad apple (or is that 97) spoils the brew so you throw the whole baby out. Not good. An equally opposite reaction to a problem is seldom productive.
To reason with moderation is the high ground.

The bad guys in Chricton’s great book were corrupt environmentalists and lawyers and stupid Hollywood types.
So the sssay is a lie from the get go.
No different from the work of most climate fear promoters, actually.
And as to consensus, Feynman, Einstein, and other pseudo-scientists all promote the idea that consensus is bad science.
What a disgusting defense by Arstechnica and the rest of the climate kooks and apologists.

“It’s impossible to attribute superior or lesser intelligence to conservatives or progressives…”
Global warming was a global IQ test with results permanently recorded on the Internet. The Professional Left from one side of the planet to the other failed.
Can you name a single prominent “progressive” who has not permanently shamed themselves with AGW advocacy? You can scrub like lady Macbeth, you can even use the sandpaper, but the putrescent stain of AGW advocacy is permanent and the shame of vilifying sceptics in an attempt to silence the truth will burn forever.
Either our radiative atmosphere (excepting pressure) has a net cooling effect on the surface or it has a net warming effect. Black or white, right or wrong. There can be no “soft landing” for the hoax. Your fellow travellers will not be slinking off to a UN sponsored “BioCrisis” or a manufactured fresh water crisis. Sceptics will never forgive and the Internet will never forget.
You have taken your political pot-shot and said “back to the science”, so I will take one last political shot and leave it. The so called “progressives” have made the greatest political blunder in history. When the SS Leftardula was taking too long to get to port Fabia, along came the SS Global Warming, with it’s powerful pseudo science engines, and every last fellow traveller jumped ship. Now you have hit the iceberg of truth and are sinking with all rodents. There will be no escape. Sceptics have smashed every lifeboat and the Internet has welded every hatch shut. Down you go…

Heh. The smartest Leftist in the world, yes, Noam Chomsky, has this to say
He also thinks that the world is still warming. Hasn’t checked in 17 years obviously.

Of all the “progressive” blatheratti, there is a special joy to be had in the utter destruction of Chomsky’s drivel. His reputation was built on years of bleating that evil conservatives and capitalists were “manufacturing consent”, but the crushing reality is that his fellow travellers and their useful idiots were the ones provably “manufacturing consensus”…
Moaning Noam, hoist by his own petard. Delicious 😉

Gentle Tramp

Konrad said:
“Can you name a single prominent “progressive” who has not permanently shamed themselves with AGW advocacy?”
Yes, for instance: Prof. Fritz Vahrenholt, Co-Author of “The neglected Sun” is a member and former politician of the leftist German party SPD. Also Helmut Schmidt, a former German chancellor from the same party, is an outspoken skeptic in this matter.
But it is fair to claim that there are more CAGW-Believers on the left political side than on the right. However, there are many CAGW-Followers from this political corner as well, at least in Europe. Thus, the “Right/Left-Division” is not a very helpful category here; it’s rather a question of “independence of mind”…
Further, it’s to hard to say, the state of believing in CAGW should be an absolute test of IQ, because many intelligent people have simply not enough scientific knowledge to make their own assessment about the validity of this hypothesis. It’s more a test of their ability resisting the social pressure of conformism.

For the record, I have never yet met a “progressive” that can’t quote some Chomsky, and they ALL think Chomsky has increased their understanding of the world and improved their lives. But that’s okay, I am also aware that many “progressives” are unaware of what they are, and some even think their “progressive” outlooks have any validity beyond mere echos of anti-Vietnam sentiment from the 60s.

Wow – that just slid by with no comment. Someone advanced the theory (never observed) of evolution as some consensus fact, others raised objection, and nobody came to the rescue of evolution-as-fact.
Things are looking up amongst this group of scientifically minded ppl. Projecting backward is pretty much the same as predicting forward.

Artificial selection has produced a vast array of canine freaks, the majority of which wouldn’t stand a chance of surviving and reproducing in the wild.
Even if, like Darwin, you had no understanding of the genetic code behind the mechanism, you would have to acknowledge that selection pressures from the environment shape the organism over multiple generations. The only difference between artificial selection (“eugenics” if you prefer ) and “natural” selection is the part of the environment that does the culling.
A mere 100 years of domestic canine “improvements”:
You don’t need consensus to be convinced of evolution: you just need to look at the mountains and oceans full of evidence. That’s probably why people who think evolution is the explanation best fitted to the evidence don’t invoke “consensus” as an “argument.”
Evolution is the 2nd most successful theory in science.

In the same way that “climate change” is used as shorthand that isn’t properly specified, a lot of times “evolution” is treated the same way.
“Evolution”, to a creationist, is the specific assertion that the species of man arose from monkeys in a defined step by step fashion.
“Evolution”, to a layman, is the assertion that species magically transform in positive ways in response to the environment, starting with amoeba from Fantasia, working their way up until they reach the pinnacle of humans.
“Evolution”, to a scientist, is the assertion that through the mechanism of natural selection, a separated group of a given species can genetically drift through mutation and selective pressures to the point where the original group (not subject to the same pressures or the same mutations) no longer can breed/produce viable offspring with the separated group. Whether or not the separated group is “better” is a question nature doesn’t care about – the group doesn’t need to be stronger, or faster, or smarter, it just has to have avoided the particular selective pressure that killed off the other competing genetic lines.
So really, when we talk about “evolution”, we *really* mean “genetic drift and selective pressures” – both of which, as you rightly point out, happen with “artificial” selection (nature doesn’t care *where* the selective pressure comes from – calling one “natural” and one “artificial” is a trope of hubris).
As for why the theory of genetic drift and selective pressures is scientific (as compared to the pseudo-science of AGW), is that genetic drift and selective pressures is *falsifiable*. The trivial example of the falsifiability is to find a modern rabbit in the precambrian, which would demonstrate, if found, something miraculous like time travel or an alien seeding our planet hundreds of millions of years ago. Another example would be finding an organism which never has any mutations during genetic reproduction, ever. The most thoroughly sci-fi-ish example would be finding such a never-mutating organism, that has sufficient genetic code to express an infinite variety of phenotypes with the same genotype, adapting phenotypically to selective pressures without ever changing genetically.

Alan – the subtitle of The Origin of Species” was “The Preservation of Favoured Races in the Struggle for Life”.
That is a fact.
What is also a fact is our horrible history of eugenics arose out of this hubris – leading from England to USA and from USA straight to Hilter and the Final Solution, and all of the forced-sterilization programs from the powerful onto the powerless in the USA and across the globe – mostly focused on dark-skinned inferior people.
Fact. Fact. Fact. Fact. Fact.
This view of evolution as some revelation saving us from the terror of religion is a huge, horrible faith-based myth.
Of course, since I am white, this obvious “fact” of evolution doesn’t affect me or my people. So, essentially, your comment is accurate – for me and my kind.

Well somebody mentioned the consensus on Dark Matter as example of where consensus is “perfectly valid [and necessary]”.
A few months ago I travelled on the train where I had the pleasure of talking to a physicist who had worked at CERN. So I asked him for an explanation of the Higgs field, and his opinion about Dark Matter. I mentioned my conviction that a magneto-rotational instability could explain the rotational properties of rotating disks of matter in space. He expressed his conviction that MOND would explain it.
Neither of us believed in Dark Matter.
Maybe he was a bad physicist.

Both of you were pushing Convictions. That is not science and thus both of you qualify as bad physicists in my book.

Rubbish, you of all people should know. You yourself have your convictions that the solar signal is too weak to explain global warming – that is a “conviction” and you might be right, however someone else like me might say “Well it is not altogether proven that emergent effects across all wavelength of light are similar and that a vatiation in the spectral distribution of light may have a significant effect” perhaps my conviction is right Leif. A conviction is simply an alternative belief, an alternative hypothesis, alternative hypotheses cause science to advance. You are a bad scientist if you dont have them

No, I don’t have any convictions. I do not have the conviction that the solar signal is too weak to explain global warming. The data tells me that, regardless of what I may want to believe. And I don’t have beliefs about this. If somebody can show me that the signal produces a significant response above the error bar, I’ll accept their analysis, but so far nobody has.

Leif – is this true? Do you actually think you don’t have any convictions? You’re not just pulling our legs?

I don’t have any convictions about science. I have lots of convictions about many other things, like freedom, honesty, etc.
In science, data trumps conviction, so better not have any. Follow the data.

Dark Matter is a conviction as long as it has not been found.

Well, it has been found, all around us. 80% of the matter of the Universe is Dark.

God would be Matter or Dark Matter or both?

I don’t think so. Dark Matter responds to gravity. Your god is probably above that 🙂

Actually Leif, I think you do. You think you are following the data, but you don’t know all the mechanisms that link solar influences to weather. Your interpretation of the data is therefore ignorant of the transfer functiom between solar and terrestrial weather. You hold the belief that solar influences are too weak to explain climate change in spite of your ignorance about a large chunk, that is what happens between the sun and the temperature emerging on earth. Rather than assert that you don’t know for sure, but it appears to be true, you proclaim full knowledge that the solar influence is certainly too weak – I claim you know too little to say that with any certainty because science lacks knowledge of all the mechanisms. That makes your declaration a belief (or conviction), it may be probable, but it is by no means a fact.
As a scientist one should be aware of the progression of competence
Unconcious incompetence – we don’t know what we don’t know
Conscious incompetence – we do know what we don’t know.
Conscious competence – we think we know what we know, but we are still working on it.
Unconcious competence – we know for sure and use it without question
Where are we currently incompetent about the Solar influence on the weather? Almost everywhere. For example the top of the sunspot cycle has major electrical effects on the ionosphere, how does that influence our environment?

Before one begins to think about mechanisms and unknown unknowns there should be a response to be explained, and as far as I am concerned, there is no response, there is no clear indication that the solar signal has a significant climate response. Lots of claims, but none that survive scrutiny.

So God is energy ? Dark energy or just energy ?

Leif Svalgaard
September 10, 2014 at 12:05 am
Okay, you say it has been found. Is it neutrinos, WIMPS, MACHOs? Which one is it?
Leif, you don’t even notice that you mistake a bundle of competing sub-hypotheses of the Dark Matter hypothesis for evidence.

ferd berple

or that our theory of gravity is incomplete.
has anyone ever shown us a single particle of dark matter? or is dark matter a hypothesis to explain the differences between gravitational theory and observation?

Dark Matter is not a product of our Theory of Gravitation. That we don’t know what DM is is not an objection. Newton clearly stated that he did not know the cause of Gravity, yet gravity certainly exists. You may benefit from a study of about how to measure the density of baryons versus that of DM, which does not depend on any theories of gravitation.