Continued from here where I said:
A friend of mine sent me a long article from The Guardian, “Denialism: what drives people to reject the truth.” To me, the article is a long, intellectual justification for name-calling.
and
I don’t agree that climate change is necessarily an urgent problem. The key word is “necessarily.” It might be urgent. I’m just not convinced on the basis of what I know of climate science. There are people who know way more climate science than me who disagree with my view and people who know about as much as those people who agree. But I’m in a charitable mood and I’m willing to later stipulate that it is an urgent problem needing radical actions in order to discuss whether the radical actions that are proposed are good ones. I will argue that many are not—using science a facts to back up my claim.
I think I might qualify, according to Keith’s criteria, as a climate denier, just as he might qualify, according to my criteria as an asshole. But I am not denying anything. I am not refusing to consider any reasoned argument based on facts. And if I question an explanation, or offer another explanation, I will do it based on facts. And I think he’s well-intentioned so I won’t call him an asshole. But if you call me a denier, I reserve the right to call you one.
I don’t think it’s possible to be entirely neutral. We all walk around with our own Bayesian priors. I have read claims of impending disaster for more than forty years, starting with Paul Ehrlich’s “Population Bomb” in 1968. The book, widely hailed, predicted mass starvation in the 1980s. Then there was the Club of Rome Report “Limits to Growth” in 1972. Whenever they’re made a prediction of dire consequences it’s turned out to be wrong. And decades of prior doom-saying has turned out wrong. So if you come to me predicting doomsday, my prior is that you’re wrong.
But I am very willing to update my prior based on evidence. And update my prior that I correctly understood the claim that I had concluded was untrue. And I am aware of the ever-lurking problem of my own confirmation bias and my own susceptibility to other cognitive errors. So I am extra careful to give “the benefit of the doubt” to arguments that do not support my prior, and less weight to those that support it.
(And by the way, I do think that’s the right stance to take unless you are a cognitive bias denier or a Bayesian reasoning denier. And by the way, Bayesian analysis is not the only tool I use to evaluate arguments and evidence. There are problems with Bayesianism. Every tool has its limitations. Including some of the methods of science.)
So, back to the article’s argument. I agree that people sometimes deny facts because they don’t want them to be true and that is because they are aware of the consequences of their being accepted as true. It’s pretty clear to me that Holocaust deniers are motivated anti-semitism, not a quest for truth. They call themselves revisionists, not deniers. But who cares. They don’t merely deny the Holocaust, they explain the “evidence” as part of a plot by the lying Jews. And some say: there was no Holocaust, but if they had been it would have been a good idea because Jews are always up to no good. The reasoning: Jews are always up to no good, therefore in this instance, Jews are up to no good. QED.
People who deny the Armenian genocide are different. They mostly agree that a lot of Armenians were killed by the Turkish government. They disagree on the number, but they’re within the same order of magnitude, unlike the Holocaust deniers who either believe the whole thing is a fabrication, or reduce the number by more than an order of magnitude. The dispute about the Armenian genocide is whether it was a genocide or simply a fuckload of Armenians getting killed. It’s a genocide if the Armenians who were killed were killed solely because they were Armenians. It’s not a genocide if a million (plus or minus) Armenians were killed because they got in the way during a war for territory and because the Armenians were (mainly) the opposite side to the Turkish government. Turkish government denies it was not genocide because they claim to be nice people and partly because they have said that they know that if they accept that it was genocide their admission will be followed by a claim for money damages.
People who are 9/11 deniers are in yet another category. They call themselves 9//11 truthers and call the rest of us deniers. Whatever. They point to evidence that it was an inside job, engineered by the US government to manufacture an excuse to attack Afghanistan and Iraq and pass the Patriot Act, and we who don’t believe that are the real deniers. I have not studied their evidence but I have looked at it and revised my prior, but only very slightly. I think they are wrong.
Almost all of the people who reject Darwinian evolution do so because of its conflict with a foundational belief: that the Bible is true and inerrant. If someone points out that one part of the Bible is obviously inconsistent with another, they will do a lot of difficult intellectual work to “prove” that there is no inconsistency. When they reject evolution they not “denying” the evidence. They are simply pointing out that it conflicts with the Bible, therefore it must be wrong. QED.
To characterize them as ignorant for not evaluating the evidence that the Bible is true versus the evidence that evolution is true is to misunderstand them. Their belief system is axiomatic—like mathematics, not evidentiary and explanatory, like science. The inerrancy of the Bible is not a conclusion reached after considering evidence. It is an axiom. The axiom. An axiom is a statement that is assumed true, without proof. In an axiomatic system you accept the axioms, and then go on and reason from there. Since the Bible is true and inerrant, then every argument that seems to show that there is a contradiction MUST be false. We just need to discover how it is false. Because it must be. Otherwise, it would be in conflict with the axiom.
You don’t have to agree to the inerrancy of the Bible to call yourself a Christian. And people who see the Bible as a metaphor can use it to lead pretty good Christian lives. But for those who do, and accept as a matter of definition that a Christian is one who believes in the inerrancy of the Bible, then you can’t be a Christian unless you accept that the Bible is inerrant. And why would anyone choose to believe that? Because it’s true. Because Axiom One says that.
So people who accept the Axiom of Inerrancy don’t deny evolution. They don’t have to. It can’t be true that species evolved on the paleontological timescale because there is no such time scale because the Bible does not allow for it. QED. There also can’t have been a Big Bang. Same reason. QED.
It’s not that they disagree with the physical evidence that is consistent with the Big Bang theory. Or the evidence in the fossil record that is consistent with Darwinian evolution. It’s just that according to their understanding of the Bible, the universe was created by God, not too long ago. So their explanation of the existence of the fossil record is not “evolution” but “that’s the way God created it.”
And some will claim that their explanation is more consistent with science. We can’t do an experiment to see whether the Big Bang is true, or that humans evolved from non-human primate creatures. So what technique of science can we use? How about Occam’s razor, which says: given two competing explanation, always accept the simpler one. On the one hand there’s an explanation involving a big bang, Population I stars made of hydrogen that go nova and produce the heavier elements according to a theory of nucleosynthesis; later generation stars that coalesce with planetary systems that contain these elements; chemistry that gives rise to replicating life forms by an as-yet unknown chemical process. Once we have self-replicating chemicals, Darwinian evolution explains how we get the full panoply of living systems. But it’s all very complex. Physical constants have to be exactly right for it to work out.
On the other hand, here’s a simpler explanation: God made it that way. So Occam’s razor says accept that explanation. Why did God make it that way? You might as well ask “Why was there a Big bang?” Or “Why were the physical constants the way they were?” Question after question. Problem after problem.
Why not be a good scientist and choose the simplest explanation: “God made it all.” Or are you an Occam’s razor denialist?
And among people who are very knowledgeable about evolution, there is strong agreement on the fundamental mechanism: “replication, variation, selection” but disagreement on many of the details. Some subscribe to a theory called “group selection.” Some subscribe to a theory of selfish genes. But then how do you explain altruism? So one can accept the theory of evolution and yet disagree with many details. So if we have one group of people who accept “group selection” and another that does not, can one group be called “deniers?” And if so, which one. The answers: of course we can call them names. But it’s not going to help us understand reality. And anyone can call the group that they want to discredit the denier group.
Same thing with climate change. Anyone who understands the fundamentals of science can understand the basic ideas. Climate does change. Science has produced records of those changes. People can debate some of the details but not the fact that climate does change.
Here is a chart showing climate change over a period of 450,000 years.
The data is from the Vostok ice cores. The climate history in the Vostok core records is consistent with other records—both for shorter and for longer periods of time. So I am not cherry-picking the data to refute clear and settled science. I am using science to make an argument about what reasonable people should agree on, and what they can disagree on and still be reasonable people.
The red line is temperature. The blue is CO2. Let’s focus on temperature and CO2 since that’s what the debate is mainly about. The present is to the left, the ancient past is to the right. So the most recent temperatures in the record are the top left of the red line. To see the evolution of climate as time moves forward, you go from right to left.
What you can see is that climate changes. You can see temperature and CO2 varying for 450,000 years with no humans around for most of it and with no significant human impact for all but a tiny bit. We can see temperature varying over a range of about 12 degrees Centigrade from higher than today to way, way colder. And we see carbon dioxide varying very substantially and in phase with temperature.
So almost none of this change is due to humans because, for almost all of that time, humans did not exist or did not have much impact. So what can we learn from this? Climate does change. It changes substantially without humans. What shall we call climate change that doesn’t involve humans? Let’s call it natural variation. There is natural variation in carbon dioxide and there’s natural variation in temperature. And they are correlated. Science shows this.
Now the conflict.
Some people believe that all of the climate change that we see today is human-caused. That’s the same as saying that NONE of it is due to natural variation. How could that be true? We have records that show climate change through natural variation for millions of years. For NONE of today’s change to be due to natural variation and ALL due to humans then either something must have happened to cause natural variation to stop or some supernatural agency has weighed in. I don’t think God has gotten involved. And I have not heard anyone suggest that natural variation has stopped. So I’m going with “some part is natural variation.”
But 100% natural? Also unlikely. We know that humans are spewing large amounts of carbon dioxide into the atmosphere. We have well tested theories of physics that tell us that increasing CO2 will increase temperature. So some of it is human-caused. How much?
I’ll go into that in the next post.
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