Thursday, August 31, 2006

Whose opinion counts for the "consensus"?

I thought I would answer a question that several people have posed to me recently. When determining whether a scientific consensus exists, whose opinion counts? My answer is: look for consensus in the peer-reviewed literature.

As I discussed in a recent post, the scientific enterprise determines whether to accept or reject a claim by repeatedly testing it, and publishing the results of those tests in the relevant journals. Claims that have been repeatedly tested are accepted, with the confidence given that claim proportional to how numerous and rigorous the tests have been. One can determine which claims have been repeatedly tested in the "crucible of science" and therefore accepted, as well as how confident we are in our acceptance of that claim by reading the peer-reviewed literature.

Viewed through my definition, there is clearly a strong consensus that 1) the Earth is warming and 2) that humans are likely to be the dominant cause of the recent warming.

Might a "consensus" position be wrong? Of course. All knowledge is provisional and subject to future revision as new data comes in. However, as policymakers, the scientific consensus is the position most likely to be correct. In particular, strongly held consensus positions (e.g., smoking causes cancer, the Earth is warming) are verly unlikely to turn out to be wrong. Policymakers can do no better than to follow the scientific consensus in formulating their policy.


Anonymous said...

I always considered consensus (when used in a scientific context) as something that arises from tens or hundreds of researchers all doing what they do but then seeing where their little bit of research fits into the bigger picture.

Following this definition (which I know many will argue with) then the question of "Whose opinion counts" is fairly simple.

John Cross

EliRabett said...

I think that John Cross and Andrew Dessler are basically saying the same thing. As a side note, this definition brings strength to the method that Orestes used to demonstrate a consensus.

Dr. J said...

"To me, consensus seems to be the process of abandoning all beliefs, principles, values and policies. So it is something in which no one believes and to which no one objects."
Margaret Thatcher

Very well said.

Andrew Dessler said...

Dr. J-

So you take scientific advice from Margaret Thatcher? If I told you that she believed in global warming, would you now believe it? Since she's apparently a credible source to you, then you should shift your views accordingly, right?


EliRabett said...

Margaret Thatcher has a Bachelor's in Chemistry from Oxford (some would like to forget). Since Oxford requires a research thesis as part of the chemistry bachelor's degree she had some experience of research and research groups.

Dr. J said...

I have no idea what Maggie thinks of AGW, she is not a scientist with research and experience in the fields necessary to qualify for my consideration as a credible source on AGW, but she certainly knows about consensus. It is primarily a political term, like majority, plurality, etc. She is an expert at politics, and knows where it leads and the compromises and deals necessary. I had no idea she has a science degree, but she does seem very sharp and intellectual, so it fits.

Ian Forrester said...

It would appear that Mrs. Thatcher was not fully cognizant of the meaning of the word "consensus" in her quote. She seems to imply that consensus is the same as taking a position midway between two directly opposing views (sort of an average) rather than its true meaning of “agreement of opinion”. Thus a consensus is reached when the views of one side are shown to be correct and unassailable except by a few dissenting voices who usually have no firm proof of their view except that it ”should be right”.

Ian Forrester

coby said...

True. I think what Thatcher is describing is "compromise" not "consensus", which in a purely political arena are probably the same thing.

Peter K. Anderson said...

There is not any 'worth' of 'opinion consensus' at all. There is the SCIENCE applied, and that the application of such is done in a valid manner so to preserve the validly of ALL incorporated theory. These details ARE presented with EACH theory, and ALL these conditionals need to be maintained. This is as each 'theory' is valid ONLY under those situations it is produced within. This is especially true with notice to mathematical forms with and attached to the 'theory'. It is NOT a situation for 'opinion' to platform that there could be a '50% chance of correctness' is only 50% of those 'situationals' are present.

The reality is that the incorporated THEORY is become VOID when those conditions used in its production are NOT present, and there is NOT any 'partial validity' that can be maintained or 'produced' into a 'summation' to give a 'validity number' for the 'final (e.g. greenhouse) theory'. This is NOT a 'validation by political process', is NOT liken-able to deciding 'what is a planet' (as a recent 'conference' determined). Infact 'consensus' has little part to play in validation of SCIENCE at all, some seem NOT to like to notice this situation.

That is as those attempting to platform 'greenhouse issues' are doing so from a platform founded in POLITICS after it was run away from SCIENCE. So it is NOT possible to produce 'validation' for 'greenhouse issues' simply by 'voting', and 'ever has this been so'. These few still have amongst them those who attempt to 'shape discussion' that is 'supportive' of 'greenhouse issues' for 'readership consumption' in the production styles typical of Political Propagandersists.

The 'greenhouse theory' misuses SCIENCE, misinterprets ENERGY and misuses ENERGY presented within the System studied to fabricate PROXIES for Temperature' that related not the Energy presenting the TEMPERATURE of the involved materials, but that ENERGY present that is SEPARATED from that measure of Kinetic Energy. That this 'temperature' is used then to contrive a 'climate change issues' further removes the 'greenhouse consensus' from SCIENCE and into the realms of FICTION.

The problem (basically) is that those Photons that 'IrR energy') are NOT being produced due to any 'temperature' of the surrounding molecules and so aren't representative of 'blackbody' radiation. Infact the energy contained in the cascade of Photons existing within the bounds of the atmosphere presents that non-Kinetic Energy released from those materials after an initial (Quantum Photonic) interaction. These Photons have a separate existence to the molecules about them & don't present any indication of the Kinetic Energy (KE) of those surrounding molecules, whose KE is presented as the VELOCITY of the molecular unit and is measured in style as 'Temperature' (or as Pressure also). Infact the Energy of the Photons within the Cascade is that Energy NOT involved in any induction of KE, yet it is THIS energy that 'greenhouse science' attempts to cite as 'temperature' when using CO2 as a temperature proxy, and this methodology invalidates ALL other supposed 'greenhouse proxies' also.

The 'greenhouse theory/effect' is unable to be produced and there is not any 'wide acknowledgement' of 'greenhouse climate control' unless you only look at the 'greenhouse-wagon' theatre teetering along as it is. It is infact that the 'opposition' mentioned is only within a small group that draw a 'line in the sand' and argue over where it should then be moved. The 'greenhouse theory' or supposed 'effect' has ALWAYS been playing into POLITICAL platforming. So it is NOT needing 'competition' to permit 'greenhouse science' to be totally ignored even, it is built on opinion disassociated even from the known materials actual properties and misuses Energy to present a 'temperature' of the surrounding molecules.

Climate change is natural, with irregular progression, the LIE is in the attempts to overlay 'greenhouse opinion' and label such as 'science'. The PUBLIC will not listen to the 'environmental lie' being platformed in Movies/Novels. It is very easy to understand if one steps away from the 'greenhouse wagon' and looks back at that 'vehicle', it remains a POLITICAL platform where 'advocates in white coats' are STILL advocates.

Validation of Theory within SCIENCE is complex, but it is NOT produced by 'voting' on 'uncertainty'.

Your's, Peter K. Anderson a.k.a. Hartlod(tm)
From the PC of Peter K Anderson

gph said...

consider. The oceans absorb co2 and are becoming acidic. Plankton and fish die and decompose emiting co2. Waste and fertilizers flush into the oceans causing algae bloom which dies emiting co2. The permafrost melts becoming peat emiting co2. This is in addition to industrial emission of co2. All the result of human activity.

Among other problems are melting ice sheets, rain forest decline, fish migrations, increased tectonic plate activity due to redistribution of pressures on the earths surface. Are these symptoms of planet decline? Will we see extinction of major species in the near future - decades? When studied together, are these varibles simply the symptomatic result of over population?

Simply stated, you can't graze but so many cows to the acre. 6 1/2 billion will soon be 9 billion. If we are stressing resources now and crippling the planet - just imagine. gph

Anonymous said...

Global warming or natural cycles is that the real issue, I think not. Politics is business, BIG business. Shouldn't the people of earth be entitled to the cleanest air and water that technology has to offer?