I'm not super excited about "expert" opinion. An expert, to quote Niels Bohr, "Is a man who has made all the mistakes which can be made, in a narrow field." A jet engine mechanic is an expert if none of the planes she works on experiences engine failure. A scientist is, almost by definition, not an expert. This is especially the case when experiments cannot be carried out. For instance, we cannot instantiate 1000 earths, vary their CO2 content, and then observe what happens. We can only model, and modeling is based on assumptions, or "alternative facts." Almost everything controversial today (e.g., drug policy, economic interventions, climate change, etc.) falls into this quasi-scientific realm. I'm not sure that there is a quick way to reach a consensus on such issues other than by having all of the interested parties slug it out in public over an extended period. I also believe we must be careful about overzealously applying the precautionary principle to the point that policies that are objectively not working become sacred cows (e.g., the War on Drugs).
Whenever I see 'expert status' debated at universities, where it is debated and criticized a lot, my alarm sirens go up. You can split hairs about what really constitutes an expert for many hours, I've even been to conferences about this topic. But funny Niels Bohr paraphrases aside, it's in reality very simple and not problematic at all who constitutes as an expert:
- Experts have 20-40 years of experience in a particular field within their discipline. Young scholars or those belonging to the academic middle field need not be counted as experts. (They may still be experts, but that doesn't mean you should resort to them for providing expertise.)
- Experts have 20-40 years of continuous publications in peer-reviewed international academic journals about the subject matter, or have been working in the field for that time in a senior role in non-academic fields (e.g. race driving, casino security, etc.).
- Experts are recognized as eminent scholars by the majority of fellow scientists who also work in the field, whether they agree with them or not. Not just scholars or average scholars, eminent scholars.
- The expert's discipline is an actual science and their field of expertise is in fact a subfield of that discipline. Fields are much narrower areas of specialization than disciplines. (Hence, priests are not experts about 'what's good', astrologers are not experts in astronomy and mechanical engineers who muse about special relativity are not experts about special relativity.)
- The expert is given the intellectual independence and has sufficient access to the evidence needed to provide his expertise.
These criteria really suffice to weed out all the pseudo-experts of the world. That's because most if not all pseudo-experts are either laymen or crackpots from related disciplines, and in any case are not recognized as eminent scholars from people of their field. Someone can be an expert without satisfying these criteria, Richard Feynman on the Challenger catastrophe, for instance, but if you want to make sure, the above criteria suffice.
Last but not least, nobody is forced to believe genuine experts, but he should also be prepared to defend his points of view as well as a genuine expert or be regarded a stupid assclown if he doesn't.
If a racing driver loses too many races, she'll eventually have to leave the field. If a casino security person presides over too many unexpected losses, he'll eventually have to exit his area of endeavor. Their expertise is under constant pressure. A scientist isn't exposed to this same pressure, nor should she be, because failure is part of the experimental process. Thus, I think "scientific expert" is a contrast in terms unless it specifically refers to one's ability to conduct the scientific method (i.e., controlled experiments) within a given domain.
For instance, consider James Hansen. There is no doubt that most climatologists consider him an expert in climatology. He ticks off many of the boxes on your list. That's fine, but the climate models he presented to Congress in 1988 don't match observations since that time [1]. That's not to say climate change (née global warming) isn't happening, but that it is happening differently than originally predicted. This nuance is lost when "expertise" is accorded to the modeler. It is lost even more when we start talking about a 97% "expert" consensus that humans are causing climate change.
Perhaps treating "experts" like predictors and somehow attaching a coefficient of determination to each one would ease my concerns.
An expert with a 50% error rate is a coin. A scientist with a 50% error rate is still a scientist, and perhaps an eminent one at that.
When tens of "expert" climatologists with an error rate of say 5% in their field testify in support of a policy that eliminates thousands of expert miners, geologist, etc. with error rates of say 0.01% in their fields, you're going to have resistance. That's a huge perceived inequality in terms of ramifications and consequences.
http://www.hopesandconcerns.org/
I'm not super excited about "expert" opinion. An expert, to quote Niels Bohr, "Is a man who has made all the mistakes which can be made, in a narrow field." A jet engine mechanic is an expert if none of the planes she works on experiences engine failure. A scientist is, almost by definition, not an expert. This is especially the case when experiments cannot be carried out. For instance, we cannot instantiate 1000 earths, vary their CO2 content, and then observe what happens. We can only model, and modeling is based on assumptions, or "alternative facts." Almost everything controversial today (e.g., drug policy, economic interventions, climate change, etc.) falls into this quasi-scientific realm. I'm not sure that there is a quick way to reach a consensus on such issues other than by having all of the interested parties slug it out in public over an extended period. I also believe we must be careful about overzealously applying the precautionary principle to the point that policies that are objectively not working become sacred cows (e.g., the War on Drugs).