Proof vs. Doubt
Often in a discussion you'll see people dismissing scientific findings as unproven without ever getting close to formulating something to support their claim that the science isn’t proven.
An important thing to take into account is the context or meaning the word "proven" is used in, because there's a subtle difference in the meaning, depending how the word is used in different situations.
As a lot of philosophers of science have stated, in a certain way a 'positive' proof is something that simply doesn't exist or at least cannot be proven ‘absolutely’. Even when a proof survived plenty of verifications and failed attempts to falsify it, it still doesn't mean the proof in the future cannot be proven 'wrong' any more. In other words, there's simply no way telling if a proof will be standing till the end of times or not; because theoretically there's always the possibility it will be proven wrong somewhere in future.
This idea that a positive proof at the very fundamentals maybe doesn't even exist could lead into dismissing every form of scientific conclusion as being 'unproven'. Of course this thought isn't compatible with how every day science works : science uses, one way or another, some kind of 'positive' proof as a mean to support a conclusion (do notice the context I'm using the word 'positive' in, I'm not saying the proof itself has to be 'positive').
Yes, scientists have to be aware that every proof can turn out to be wrong at some point in the future. But this notion doesn't paralyze science because a 'positive' proof isn't discarded by expressing nothing more than the thought that it could be wrong. Nor is it rejected on grounds of the notion at the heart a positive proof doesn't exist. Rejecting a proof on such grounds would imply rejecting science.
One has to make a clear distinction between the "philosophical" meaning of the word proven and the concrete daily use of the concept (positive) proof.
From a "philosophical" point of view, an 'unproven assumption' vaguely has the sound of a pleonasm in it.
In some fields of science, you can have a nice mathematical proof, but in most earth sciences, a proof often will consist of estimates based on some sort of assumptions. The scientific question regarding the assumptions made, is whether those assumptions have been built up the way they should. Or have been ‘proven’, to call it differently. Such a positive proof which will only become 'unproven' by demonstrating some sort of flaws in it. In a debate, often you’ll see a skeptic getting stuck in lots of insinuating and suggesting things could be wrong. Which, as just stated, doesn't disprove anything.
I like this quote (certainly with Inhofe's "650 scientist SAY that" list) which can be found in the first chapter of IPCC's AR4 :
Indeed, when Albert Einstein was informed of the publication of a book entitled 100 Authors Against Einstein, he is said to have remarked, ‘If I were wrong, then one would have been enough!’ (Hawking, 1988); however, that one opposing scientist would have needed proof in the form of testable results.In discussions, I’ve noticed often skeptics will express an unwritten law that says that whatever the facts are, there may not be any actions imposed by governments. By claiming there's no consensus, and constructing lots of doubt about the scientific certainties, skeptics like libertarians are able to convince themselves there's no need for action on the subject of AGW because there's no proof there actually is an AGW.
Such (eventual) governments actions are not rejected because science is wrong, but because of a vague idea of doubt it could be wrong or unproven, so there's no need to act (yet)
Lobbygroups have understood very well that by creating such doubt amongst the public is a very useful way of preventing any actions on whatever the subject will be taken because there'll be no support for such actions amongst the general public.
This tactic of manufacturing doubt has been given some attention on this blog before. As said in that previous post, the aim of the skeptics-lobby was to create confusion about the views of the scientific community. And with success. It's a tactic first used by the tobacco-lobby when they attacked scientific conclusions about the relation between tobacco and cancer and has been further refined ever since.
Daniel Engber describes it as follows in his paper "the paranoid style in American Science"
This corporate strategy of "manufactured uncertainty" has become only more refined in the last 40 years. According to former Assistant Secretary of Energy David Michaels, whose startling new book, Doubt Is Their Product: How Industry's Assault on Science Threatens Your Health, comes out this week manufacturers routinely hire "product defense" firms to challenge scientific findings and stave off government regulation. Scientific consultants are brought in to dust off and reanalyze data sets, group and regroup subject pools, and dream up confounding variables-all so that a given study can be discredited as inconclusive or, worse, labeled as "junk science"The way to reach such doubt is easy, and whether the arguments are any good isn’t important at all because : throw enough dirt, and some will stick.
Because of all the lobby work, a lot of people have the impression there’s a lot of arguing going on within the scientific community itself whether there actually is a human induces global warming. Now it is clear there’s no unanimity, but the AGW is much more supported than the general public often thinks.
Professor Naomi Oreskes, a science historian, did have a closer look at how scientists themselves think about anthropogenic global warming in a paper on "The Scientific Consensus on Climate Change" For this, she did a random scan through peer review literature. Her conclusion is very clear :
This analysis shows that scientists publishing in the peer-reviewed literature agree with IPCC, the National Academy of Sciences, and the public statements of their professional societies. Politicians, economists, journalists, and others may have the impression of confusion, disagreement, or discord among climate scientists, but that impression is incorrect. (2)No matter how hard skeptics have tried to create the illusion scientists disagree themselves on the topic, the Oreskes paper makes clear there's little controversy within the scientific community.
Of course the fact there's a consensus by itself by no means proofs anything. The only conclusion which can be made is the idea that publishing scientists don't agree on the topic is wrong. Or in other words, it’s does indicate there’s a lot of noise produced by a certain lobby, noise that isn’t represented within the scientific community itself. Which demonstrates how powerful the lobby's tactics have proven to be…
The case of Simple logics
During discussions, often I see people with little or no scientific background debating the subject of climate change as they seem convinced just a little "common sense" definitely is more than sufficient to join a debate on a scientific issue.
Also, I’ve seen people express a firm belief that a logician can help finding fallacies scientists aren't able to see. They are convinced knowing the ancient Greek philosophers can help finding flaws in climate science. The case of Aristotle vs IPCC.
The important thing they completely fail to see is that having no scientific background and without having sufficient knowledge on the topic; you probably won't even understand the arguments used, the result being 'simple' logics won't bring you far in finding fallacies. Also, a layman will often fail to incorporate the science that is not mentioned in the article, whereas this science usually is necessary to make a valid judgment on the subject.
Actually, a lot of lobby arguments consist of cherry-picked conclusion, where the flaws aren’t in what they wrote, but in what they didn’t write. While everything written in the article can be 100 % correct, the paper can be wrong. Not having the background makes it impossible to detect such faulty science.
Earlier I’ve written, half-mockingly, that "common sense" is the thing every scientist fears coming out of the mouth of the layman, because way too often "common sense" equals "nonsense". The layman will often fail to detect a certain process with as a result the layman’s simple logics will demonstrate nothing more but the layman's lack of knowledge on the topic.
As an example, an argument I've heard several times being used is that CO2, because it's heavier than O2 should be 'hanging' lower in the atmosphere than more lightweight gasses like O2. There's one thing this simple logics fails to see though: the fact there's turbulence in the atmosphere resulting in a fairly good mixture of the different gasses, making the lower atmosphere rather homogeneous. Only at very high altitudes (> 80 km) there indeed will be a separation depending on the molecular weight. Not knowing this extra factor made the"common sense" fail. The common sense was simply ... too common
UPDATE : Mike Kaulbars of the excellent greenfyre blog wrote a post dealing with some more fallacies and logical flaws in often heard arguments : Have you stopped debating your climate science? Well worth reading !