Saturday, November 15, 2014

Global Warming and the Controversy: What is Scientific Consensus? Continental Drift as Example.

    One common way of attacking the mainstream of climatology for its "global warming consensus" is to claim that consensus is just that sort of authoritarian "group think" that Galileo confronted in the Inquisition.  A companion claim is that mainstream climatologists have abandoned "the scientific method".  Some of those who say they have a case against AGW are likely to say that they are practicing the true "scientific method" and anyone who doesn't accept their experiment(s) or studies as decisive must be rejecting the scientific method.  They may also delve into the mainstream studies.  Global warming dissidents (who rarely sound to me like true skeptical thinkers) often cite studies by scientists who would be surprised to learn that anyone is saying their study disproved AGW, so it is often not scientists, but "science critics" claiming the scientific method has been abandoned by mainstream climatologists.  One person with whom I recently argued (on Facebook) said "When I went to college and took experimental psychology, the premise of experimentation was to challenge existing theory" and later "There is a scientific experimental process ... propose a postulate, select your population or test material, identify and isolate variables, run your test, draw conclusions, repeat, publish, then stand up to challenge."

    In my previous article, "Finding Your Invisible Elephant. A Science Requires, and is Shaped by, a Tractable Subject Matter" I argued that a hallmark of a mature science is that its methodology can be led in unexpected directions by the set of phenomena it studies, and much of the methodology does not fit that simple description.  Different sciences lead to different methods, although I believe all sciences use the classical scientific, or experimental methods on occasion, just not exclusively.

    Astronomers, who try to tell us what the universe consists of, turn their very high tech telescopes to the skies, and go bit by bit over the database of images.  They say "this looks like one of those", and if on closer and closer observation, it looks more and more like one of those, they are kind of relieved, and kind of disapointed, because this isn't the day they see something that nobody else knows about.  If they can't identify a thing, they will try to do "whatever it takes" to arrive at some understanding.  Some facets of "whatever it takes" will consist of choosing populations ... isolating variables, etc. but consider how we got here.  Does poring over vast amounts of data looking for something interesting fit that paradigm?  To me, no, I don't see how it does.  And then when they have something mysterious, the next step may be to get someone with a very different sort of telescope to take a picture of that spot in space, and pore over it and see if it in any way makes sense.

    In the late 18th and early 19th centuries, biologists were almost exclusively devoted to collecting and examining specimens trying to fit them into a sort of "family tree" of life, even though they didn't have the evolutionary theory that said it was kind of a literal family tree, but on closer examination of how all the specimens fit together it seemed more and more natural to think of it as a kind of tree.  Somehow they got an insight that some variations were more essential than others, so that species that varied in those ways were not just different species (two leaves possibly on the same twig), but different genuses or families ... I.e. on different branches.

    There is a wonderful case study in Miriam Solomon's book Social Empiricism, of how over several decades, a consensus was reached on continental drift i.e.  plate tectonics.  Specialists in far-flung fields had a stake in the theory, first put forth by a German geologist and meteorologist in 1915, but not taken very seriously for a couple of decades.  There were geologists studying the formation of mountain ranges, paleomagentologists who studied variations in the world's magnetic fields over millions of years (there are some very specific local patterns, especially as it turns out, around the deep trenches of the oceans).  There were paleologists with data to consider about the movements and evolution of species across different continents -- how did they get from one continent to another (the idea that continents far apart were once in close contact helps explain many of these patterns).  And there were geophysicists, who would have to explain in terms of physics, just how it could happen. Those in some specialties soon found facts to support the idea, while others for a long time found very little supporting evidence in their fields.  As a result, the different fields came to accept the theory one by one, some lagging by a decade or more, even in some fields writing satirical poems about the believers in continental drift.  Oceanographers were among the last converted, but then became major contributers to the theory as they made discoveries about the ocean bottom that helped explain it or were explained by it.

    This kind of process is really what is meant by scientific consensus.  It is not groupthink, but different specialists deciding whether their field supports a theory or not, and as long as one specialty holds out, those who feel convinced of the theory remain uncomfortable, wondering if those other specialists, whose work they don't understand so well, know something that we don't.  When scientists in all these diverse began to regularly produce discoveries that helped explain or were explained by continental drift, there was a consensus.  Note that even the Nobel prize winner in one field may have to rely on abstracts of papers in another field, and believes in the general competency of the other field, even when they are in disagreement -- not that some people don't violate that atmosphere of civilized respect occasionally, but it is the general rule.

As long as a proposed theory leaves one or more major disciplines skeptical, general science publications will tend to say the matter is controversial.  It is generally only when the last discipline(s) are convinced that their field can confirm the theory that these publications say there is a scientific consensus.

    I began to read science seriously around the time when continental drift became a settled question in science, when plenty of older books and articles still referred to it as controversial.  I've watched the growth of consensus about global warming not terribly closely, but the process looked very similar (to me) to that of continental drift, moving from "this is a theory that some scientists have" to "still controversial" to "scientific consensus".

    Any single paper or piece of evidence for global warming should not convince one, and some wouldn't provide any argument at all without combined with other bits of evidence.  Scientists look for many demonstrations from many different angles, and keep looking even after they are convinced.  Likewise, any single anti-AGW argument/demonstration is not going to turn the world around.

    The papers I've received from non-believers in global warming have generally looked flawed to me.  The author, certain that he has made a great demonstration of something may claim his work singlehandedly disproved AGW, and might -- I think only if out of touch with the real science community, be convinced that scientists have become corrupt, and are no longer working according to "real" scientific principals, but I see no sign of that.

     It has never been the case that the most recent paper determines what is believed in a field.  If there is a contradiction than at least one piece of the puzzle must be flawed, but it could as easily be the latest one as some older one (or maybe to accept the latest demonstration, one must reject vast numbers of older ones).

Claims of Ideologically Driven Global Warming Agenda Seem at Best Greatly Exagerated.  One Example to Consider: Judith Curry

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