Since Skeptical Science published the Pac Man of The Consensus Project, the benign word consensus has stirred a surprising amount of controversy. I had already started drafting this post before, as I had noticed that consensus is an abomination to the true climate ostrich. Consensus in this case means that almost all scientists agree that the global temperature is increasing and that human action is the main cause. That the climate ostriches do not like this fact, I can imagine, but acting as if consensus in itself is in bad thing in itself sounds weird to me. Who would be against the consensus that all men have to die?Also the Greek hydrology professor Demetris Koutsoyiannis echoes this idea and seems to think that consensus is a bad thing (my emphasis):
I also fully agree with your statement. "This [disagreement] is what drives science forward." The latter is an important agreement, given a recent opposite trend, i.e. towards consensus building, which unfortunately has affected climate science (and not only).So, what is the role of consensus in science? Is it good or bad is it helpful or destructive, should we care at all?
Credibility
In a recent post on the value of peer review for science and the press, I have argued that one should not dramatize the importance of peer review, but that it is a helpful filter to determine which ideas are likely worth studying. A paper which has passed peer review, has some a-priory credibility.In my view, consensus is very similar, consensus lends an idea credibility. It does not say that an idea is true; if formulating carefully a scientist will never state that something is true, not even about the basics of statistical mechanics or evolution, which are nearly truisms and have been confirmed via many different lines of research.
You could thus say that peer review of an article, is a first step on the credibility ladder. The longer an idea holds, the more people have invested more time in studied it from many different angles, the more credibility an idea gains. A consensus among the people that actually studied the problem is stronger than a consensus among people that did not. In this respect, I value the IPCC reports, where groups of experts described our current understanding, a better information source on the consensus as the counting of scientific articles performed in The Consensus Project. Most of the scientists acknowledging the climate consensus, will not have studied the problem in much detail.
Credibility, makes the probability that a theory is wrong smaller. Consequently, it also makes the honour of finding a problem larger. There is nothing more beautiful for a scientist as to destroy a consensus, no better way to show that you are a good scientist. In principle, the bigger the consensus, the better. However, the bigger the consensus, the more difficult is will also likely be to find a problem with it. Thus you need some confidence if you go after a big one. It is likely smart to build your scientific career on a mixture of problems with varying degrees of difficulty, only trying to destroy century old theories is a high-risk strategy. Often it is possible to first build up evidence for a smaller question, before you go for the big kill.
Just as an expert can ignore peer-review and simply judge ideas from the non-reviewed literature himself, there is no reason whatsoever to respect the consensus opinion in the field you are working in. If you have a good idea and strong arguments why the consensus is wrong, go for it! If a new idea requires the consensus of one or even neighbouring fields to be wrong as well, the situation becomes complicated. That would require a lot of study to become expert in those other fields and quite likely in the end you will not find the hole you need in their consensus. If you have nothing else to work on or the consequences would be enormous, by all means try it, but I would not prioritize pursuing such an idea.
Dikran Marsupial summarises this section very well:
... the existence of a consensus is not scientific evidence of anthropogenic climate change (and nobody is claiming it is), the consensus is a result of the scientific evidence of anthropogenic climate change.
Standing on the shoulders of giants
It is a bon mot that we can only see so far because we are standing on the shoulders of giants. This foundation, an indispensable network of interlinked ideas, is the consensus of the preceding research. Not all of it is right, it does not have to, it should help in finding new fruitful questions that in the end help us understanding the world a little better.If you want to add a new piece to this network, you may have to destroy a piece of the old network because it does not fit. The more "consensus" you would have to destroy, the less likely it is that your new idea will turn out to be an improvement. By the way, often you can also do something completely new, improve methodologies, find interesting consequences of known theories, etc. Thus often there need be no conflict whatsoever.
I have always wondered why the climate "sceptics" often claim that CO2 is of minor importance as a greenhouse gas. That would mean that either quantum mechanics or the radiative transfer (RT) equation should be wrong. The RT equation is so basic, that it if were wrong, also much of astronomy, remote sensing by satellites and many laboratory experiments would be have been based on the wrong equations. That is quite a consensus the destroy. Not impossible, but highly unlikely, especially by someone with almost no expertise in any of the fields.
It may take a bit more thinking to realise their importance, but my advice to the ostriches would thus be to look at climatic feedbacks, they are unique to climate science and thus have much less consensus behind them and are consequently much more likely to be wrong. Strong negative feedbacks have the potential to make the global temperature increase due to CO2 very small, which is all a climate ostrich needs. My personal favourite feedback would be the cloud feedback, Roger Pielke Sr. would probably mention land-surface feedbacks.
Encouraging dissent
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Obey, photo by Peat Bakke, CC2.0 license. |
Dissent in itself is neither good nor bad. Ideally a scientific paper should be so strong that even if someone initially held the opposite opinion, he can only agree that the article is right. In this respect, you should strive for consensus. In praxis, you will often need multiple papers to build up a case and answer criticisms you did not think of in the first paper. Thus in praxis there may be a phase with dissent, but I do not see it as something to strive for as a scientist.
Still, humans have a tendency to seek consensus and to copy opinions of high-status individuals. To counter this tendency, the scientific community should explicitly encourage dissent, naturally without relaxing our quality standards. Dissent, just for the fun of it, with unfounded arguments and rookie errors only hinders science.
Science and society are two very different realms. In a democracy it is much more important to encourage dissent. In a democracy there is not just one truth, different people have different interests. Even if the interests of everyone would be the same, the kind of questions that need to be negotiated are too complex to be proven optimal. Science done right, on the other hand, splits up problems in sufficiently small questions that have a clear answer. (This is also why governments by experts are bad, experts are not able to deal with this ambiguity, think in terms of one right answer and not experienced in building coalitions with groups of different interests.)
In science dissent is a sign that there is work to do. In a democracy it is the natural state.
Climate ostriches
Interesting is that that consensus is not opposite of dissent. As HotWopper noticed the climate ostriches do not agree about much:WUWT deniers can't agree about what is happening to the climate (it's the sun, it's natural, it's not warming, it's cooling, we're heading for an ice age, it's thunderstorms, there is no greenhouse effect, it's cosmic rays, it's warming, it's not warming, it's ENSO, it's an ice age) - but when it comes to conspiracies they all agree that climate science is a hoax! A conspiracy! A scam! A SECRET scam!
While every ostrich seems to have its own alternative hypothesis, that is there is no consensus, there is also no dissent. Like a pack of wolfs the regulars at WUWT attack people who dare to claim that the global temperature is increasing and that humans are the main cause. However, if one of pseudoskeptics makes an obvious mistake, e.g. a clear misquotation, no one will criticise this, there is no sign of dissent.
If the climate ostriches would like to develop a better alternative hypothesis, which I doubt after reading WUWT for over a year, it is time the ostriches allow for dissent and start discussing the strengths and weaknesses of their ideas and not just the stupidity of scientists and scientific ideas.


















