Consensus an a narrow sub-discipline of one area of research (maize genetics, say) and consensus on the broadest cross-cutting quesiton ever encountered in the history of science (AGW) are two different things entirely

Astute observation. Yes, AGW is a fundamental paradigm change in science and has consequences for the whole of society. It’s as significant as Copernican or Darwinian theory and must not be accepted as true based on the esoteric “knowledge” of a handful of scientists.

Has anybody actually surveyed every (peer-reviewed) paper with respect to climate change to assume to know that there has been an affirmative consensus by way of the literature? Is this a reasonable way in which to assume a consensus? My impression is that many climatologists and climate researchers rarely provide an assertion either way in their papers.

“¢’‚¬? Margaret Thatcher
http://www.learn-usa.com/transformation_process/~consensus.htm

Meteorologist Likens Fear of Global Warming to ‘Religious Belief’
With respect to science, the assumption behind the [alarmist] consensus is science is the source of authority and that authority increases with the number of scientists [who agree.] But science is not primarily a source of authority. It is a particularly effective approach of inquiry and analysis. Skepticism is essential to science — consensus is foreign,” Lindzen said.
http://www.marshall.org/article.php?id=265
Climate Alarm- Where Does It Come From?
http://www.marshall.org/article.php?id=264

I would ask you, John: when you face a medical decision, do you attempt to see what the bulk of experts in the field say should be done and then follow that course of action? Or do you follow the Crichton/Iraq example, and assume they must be wrong and do the opposite? I happen to believe asking the smartest people we can find for their consensus view remains a good choice, which is why we do it all the time. I think you’re right that a consensus isn’t worth much “in the absence of cold, hard, evidence that has been checked and audited and replicated,” and that’s what’s happening now.

I think there’s a false dichotomy in your argument. I am not a contrarian (despite John Hunter flinging that absurdity in my direction). It does not make sense to me to disregard what experts are telling us, providing that the evidence presented has be tested and replicated. A scientific consensus without verification is a confluence of opinion – it does not equal a single empirical data point.

But history has thrown up many examples of scientific consensuses that were wrong, and despite being wrong, continues to disregard and suppress the truth using political power. Scientists, especially modern climate scientists, are very blind to their own prejudices and biases on occasion, and are loathe to accept their own error. For this reason alone, Kuhn remarked that science advances “one funeral at a time”.

Scientific consensuses are at best stop-gaps for knowledge we do not yet have, but they are not knowledge, and left to themselves, rapidly turn into political quagmires. I used the example of the Iraq War as a classic example that expert consensuses do not mean that anything is there, and in my view Bush threw caution to the wind, when caution and waiting for solid fact would have been better.

So it is with the Kyoto Protocol and the nature of this “scientific consensus”. It is a confluence of opinion in the absence of unambiguous evidence. If the Kyoto Protocol is actually about reducing climate change, why is it so ineffective? If climate models are so accurate, why can’t they predict something, instead of being used to rewrite the past? Why does climate science feel it can behave in a partisan and political fashion and yet scream in horror when real partisans and politicians get involved? Why do some climate scientists feel it necessary to constantly misconstrue or malign other researchers based upon their supposed links to fossil fuel companies rather than deal with evidence in a professional manner?

When I talk to scientists about Einstein’s Theory of Relativity, I get chapter and verse on its mathematical robustness and its 100% empirical record. No consensuses are invoked, and I am encouraged to ask tough questions about its implications without anyone impugning my possible links to shadowy Newtonian thinktanks.

Getting back to your point, when faced with a medical crisis, I rely on experts. But if large amounts of money are involved, then no-one is immune from error and checking and auditing of types of treatments, types of drugs, dosages, surgical success is a requirement of all modern healthcare programs. I rely on a consensus of experts to tell me what the consensus is, but also to rigorously check that that consensus continues to be backed up by unimpeachable empirical data.

Getting back to MBH98, I see an untested and unvalidated study which flies in the face of most studies carried out before and quite a few since, being written into a bureaucratic and unneccessary review of the state of climate science and being unjustifiably promoted as the “consensus view” – then when someone checks the method and finds very large flaws, the screaming begins.

Ultimately I suspect Crichton is confused and thinks of himself as a scientist and historian of science instead of his truer nature – a marketeer of science.

According to Kuhn, normal science “is predicated on the assumption that the scientific community knows what the world is like”…”normal science often suppresses fundamental novelties because they are necessarily subversive of its basic commitments.” Paradigm-based research is “an attempt to force nature into the preformed and relatively inflexible box that the paradigm supplies.” Kuhn adds that most scientists are engaged in mop-up operations, much of which is intended to stifle dissent for the prevailing paradigm.

I often hear people say things like “the vast majority of credible scientists believe global warming….” and I think “so what?” Does AGW theory “explain all the facts with which it can be confronted”? If so, does it matter how many scientists believe it? If not, does it matter how many scientists believe it?

The vast majority of climate scientists believed Gilbert Walker was wrong about ENSO. The vast majority of geologists believed J. Harlan Bretz was wrong about the Missoula floods. The vast majority of geologists believed Alfred Wegener (a meteorologist, for goodness sake!) was wrong about continental drift. I could go on and on…

I only wish we could excise the phrase “the vast majority believe…” from our collective vocabulary because it doesn’t mean squat! I suspect Dr. Crichton would agree.