What does scientific terminology mean?

[Pangloss]

[copied by swansont: This came up in another thread]

 

No, I disagree. Whether global warming is caused by humans is something that can be analyzed and discussed using science, and while you claim it to be a perfectly defendable position, there is a decided lack of actual scientific defense of the position, in the threads I've seen. The calls for evidence to back that position up are scientific ones, not politically correct ones. The arguments against AGW are generally bad scientific arguments — logical fallacies and inexcusably poor scientific practices, and in some cases, out-and-out misrepresentation.

 

This is a good example of what I'm talking about, so I appreciate that you brought it up. You've done something above that even the IPCC couldn't do -- determine factually that global warming is caused by humans and declare the debate over. Millions of scientists can't do that, but here at SFN it's a proven fact that cannot be refuted. That's awesome. Can I get in on it when we publish?

 

... and you don't see a problem with that. Well okay, good on you, but I do. Sorry. Like I said, I don't think it ruins the board, because I've watched you hear people out on the subject and require that responders be polite. But I do think it colors and reduces the quality of discourse on the subject when we have adopted a foregone conclusion that isn't even accepted by the scientific community.

[swansont]

I copied this over because I think it points out some of the peculiarities of scientific terminology. It is NOT intended to get into a debate about the particulars of global warming or any other finding of science; the emphasis here is what is meant by words like "fact" and "proven" in the scientific lexicon.

 

This is a good example of what I'm talking about, so I appreciate that you brought it up. You've done something above that even the IPCC couldn't do -- determine factually that global warming is caused by humans and declare the debate over. Millions of scientists can't do that, but here at SFN it's a proven fact that cannot be refuted. That's awesome. Can I get in on it when we publish?

 

The IPCC did come to that conclusion in their latest report; the weight of the evidence is that GW is real and caused by humans. Nothing I said was meant to imply that such a finding is not challengeable, nor that it would be impossible to refute. Scientific debate is never over — it always needs to be tested. What I was saying is that the arguments that had been presented here were seriously deficient.

 

When scientists write reports or papers and present their results, they try and quantify their certainty. Science isn't deductive and 100% certainty, or having things be "proven," is not possible, and the vocabulary that is generally used reflects that. There are many examples of scientific terminology having very narrow definitions as compared to the everyday use of a word — one need go no further than the use of "theory" to see how that gets misused and abused.

 

Similarly, here. The IPCC report says (from http://en.wikipedia.org/wiki/IPCC_Fourth_Assessment_Report)

 

"Warming of the climate system is unequivocal."

"Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations."

 

They define terms for quantifying certainty and uncertainty in the introduction:

 

Where uncertainty in specific outcomes is assessed using expert judgment and statistical analysis of a body of evidence (e.g. observations or model results), then the following likelihood ranges are used to express the assessed probability of occurrence: virtually certain >99%; extremely likely >95%; very likely >90%; likely >66%; more likely than not > 50%; about as likely as not 33% to 66%; unlikely <33%; very unlikely <10%; extremely unlikely <5%; exceptionally unlikely <1%.

 

Notice how there is no "100%." There never will be, because of the nature of science. The term "proven" won't show up, because the implication of that term is from deductive reasoning. (Of course, detractors of different scientific findings use this to exploit the terminology outside of the science arena) So even though "proven" and "fact" aren't presented, it would be incorrect to conclude the opposite — that this was somehow not demonstrated, or the scientists are completely unsure of the causes. The scientists have determined the finding to over 90% certainty.

 

So these scientists have made a determination. If you want to challenge this, or any other scientific finding, go ahead and do so (in the appropriate area of the forums), but logical fallacies (like equivocation and strawmen) do not count as scientific challenges.

[Mr Skeptic]

As opposed to "political terminology" where "absolutely certain" can mean "less than 50% probability", and where "theory" can mean "wild-assed guess" or "scientific law" depending on which is convenient at the moment.