Is it science?

One of the things I like to ponder is how to decide whether something is science or not.  An attempt to come up with a clear demarcation criterion is Karl Popper's, which gets more widely distributed as being "If it isn't falsifiable, it isn't science."   I'm not sure what he said himself, but philosophers tend to write books on these topics, rather than short sentences, so I'll guess that some details are lost in this version.

The question arises here because a recent question at the question place (yes, Robert, that's exactly what it's for) mentioned Popper.  I'll give a different response and discussion here.  (Same conclusion*).

For some cases, Popper's falsifiability criterion works well.  Religion is not science.  There is no observation, experiment, or test that will tell someone that their religion is wrong.  No matter what you observe, the religion can accommodate it.  Same thing for mathematics, actually, as it isn't necessarily concerned with observations.  Unfortunately, those (theology and mathematics) are the only two areas which can lay claim to absolute Truth (of a sort -- mathematical truth is only about mathematical things).  Science is left with only approximate truth -- the theory seems to work pretty well, the observations are pretty reliable.  But not absolutely reliable, and not absolutely perfectly.

For others, though, it's more difficult.  In the later 1800s, astronomers observed that the planet Mercury wasn't where it was supposed to be according to Newton's laws.  Its point of closest approach to the sun (perihelion) was moving by 43 seconds of arc per century too much$.  If Popper's criterion were correct, astronomers and physicists should have immediately thrown out Newton's laws and gone looking for something else.  Instead, some patches were suggested -- like a planet 'Vulcan', orbiting even closer to the Sun than Mercury, in just such a way to cause Mercury to behave as observed.  But it was never observed.  Eventually, Einstein proposed his theories of relativity to expand on Newton's laws.  Among other things, they explained why Mercury wasn't where Newton expected it to be.

For climatology, Popper is not so much relevant, or at least doesn't pose very much difficulty.

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Not even wrong

Wolfgang Pauli is said to have responded That's not right. That's not even wrong. to a paper.

"Not even wrong" is a good summary of a number of psuedoscientific things. I was reminded of this by a document that wanted to toss aside most of the last 100+ years of science on climate. I'm not going to dwell on the document itself, but it seems worthwhile to look some more at the 'not even wrong' flags.

But first, the term itself. If I said 2+2 = 5, that'd be wrong. If I said 2+2 = kumquat, we're over to not even wrong. One form of 'not even wrong' is that the answer has nothing to do with the question. This shows up often in blog comments about climate where a question like "Has the temperature risen in the past 100 years?" is met with responses like "It was warmer 70 million years ago", "You're just trying to take away my SUV", "It's all natural." Not even wrong -- the response has no connection to the question.

Different version is to start with a falsehood and then draw whatever conclusion you'd like. ex: "Meteorologists don't allow for urban heat island effect, therefore there's been no real warming the last 50 years."

Nonscience and pseudoscience

One of my interests is pseudoscience. There are a couple of lines I like to draw, between science and nonscience, and between nonscience and pseudoscience. I think science is a good thing, pseduoscience is a bad thing, and nonscience can be anything in between.

Let's start with science. Ultimately, my philosopher friend tells me, it is an impossible job to cleanly define science such that everything which is science is inside the line you draw, and nothing that isn't science is inside. Ok. So I have some fuzzy boundaries for inside vs. outside. Some things might move more cleanly inside, in time, and others will start fuzzy and then move outside. For the most part, though, the fuzziness doesn't cause me problems.

Inside science we have things where people are trying to understand the natural universe, using sharable methods and data, and is subject to further testing. Each of those elements is important. Science is about understanding. Making use of your understanding (say to build a better computer) is engineering. This is one of the many good things that isn't science. Science is about the natural universe. If you're discussing the nature of God, whether there is one, etc., you're over in theology, not science. If you, say, have an experiment where only you can get a certain result, and if I stood next to you and looked I wouldn't see what you did, then you've left science. The most difficult part, for both scientists and non-scientists, is the last -- whatever your conclusions and understanding are today, you have to be open to new data that will cause you to revise yourself tomorrow.

This last is perhaps the quickest method to find pseudoscience. The related point is, in science you don't start with your answer. The flat earth and young earth sites over in the 20 links game all start with their conclusion that the earth is flat, or young, and then assemble whatever arguments they can, however contrived and ultimately dishonest, to support their conclusion. A useful question, then, is "What evidence would cause you to change your mind?". If there's none, the person isn't interested in the science.

Having divided to science and nonscience, keeping in mind that 'nonscience' is not a slam, it's time to think about pseudoscience. I've got a shelf or two of examples on my bookcases at home. Essential to being pseudoscience is that the authors/fans/... have to claim that they are indeed doing science. Baseball, painting, theater, plumbing, ... are all good areas and aren't science. But it's also the case that none of them claim to be science. In baseball, I think the designated hitter rule is bad. This isn't a matter of science; no evidence you present will (at least nothing I've heard in 40 years on the topic) change my mind. But no problem, it isn't science.

Where we get to the pseudoscience is with the claim that it is science, even though it fails to be science. So, for instance, it is possible that the earth really is flat -- if we're being scientific we have to be open to the possibility that tomorrow we'll get a batch of fresh information about optics, gravity, etc., that will lead to the conclusion that the earth is flat after all. But the flat earthers are maintaining it in spite of the fact that there is not such evidence now.

Perhaps my favorite pseudoscience is biorhythms. It's something that could have turned out to be science. The problem only being that when it didn't, the believers didn't stop believing that it was. The idea here is that your body has certain rhythms (which it does in some things) that could predict whether you were in better or worse shape, and more or less accident prone. We're ok so far -- the topic is natural universe, the data are sharable (did people have more accidents, when were they born, where were they in their biorhythm(s), etc.). But when it came down to comparing the observations to the predictions, it failed. There were some problems with the idea (ex: how did the body maintain such a precise timing of the rhythms over a lifetime?), but if the predictions accorded with observation, that's ok. Just means more research is needed, this time to answer those questions.

I first read about this in the 1970s. At that time, one of the books mentioned that there really was a lot of data in support of the idea, but it was in a steamer trunk on a ship that sank during World War II. Bit puzzling that with almost 30 years since the sinking the proponents hadn't managed to find more data, but I was younger then and it didn't strike me as odd as it should have. In the mid-1990s, I looked again (forget the reason) and a recently published book was repeating the steamer trunk story. Come on! Another 20 years on, 50 years after the event, the fans still hadn't managed to find new data. This is 'the dog ate my homework', not science. If a process that is supposed to be going on today can't be supported with observations today, you've lost the 'sharable data' part of being science.

Pseudoscience is unfortunately common when you start looking for information about climate. On the other hand, most of it is fairly easy to identify, being not even as close to science as the biorhythm business.

Climate is always changing

The subject line is a comment that surface surprisingly often in the literature of folks who want to deny that climate is changing, or if it isn't, that any of it is due to human activity, or if it is, then it will be good for us. Whatever. The science of interest here is the notion of climate change, how fast, how much, how often, and the like. The human side of concern ... we'll get to a bit of that as well.

As we look through the period where we have thermometers (the last 100 or so years) recording temperatures, we see that there are indeed changes from year to year (though a year is too short really to call climate) and decade to decade (a better period to average over). But this includes the period of significant human activity (the now 6+ billion of us), so doesn't necessarily tell us a lot about what the climate does without human effects.

For longer range, say the last 600-2000 years, we have climate proxies that tell us about climate without being thermometers. Tree rings and ice cores are two such sources of proxies. When we look here, we see that climate does change decade to decade, century to century, and even millennium to millenium. The changes are small, tenths of a degree for the global average (and the longer a period you average over, the smaller the changes). But they're observable and present.

Even longer term, we still have ice cores (to 800,000 years ago), and then also start looking at marine sediments (to about 100,000,000 years ago). We see here that climate still changes, even on 10,000 to 10,000,000 year time scales. A very large change, 5 C or so global average, is associated with the northern hemisphere ice age cycle. About as much is associated with the start of the Antarctic ice cap about 35 million years ago.

The exact causes for the changes are a subject of study with some good answers and some not as confident. They include carbon dioxide (greenhouse gas) changes, orbital variations (the earth's orbit isn't exactly constant), continental drift, and land surface changes.

So what do we need to consider as humans with human interests regarding climate? As scientists, we want to understand everything, through all of time. But as citizens thinking about policy, we can look at a few things. One thing is, although there have been large changes to climate before, humans weren't around for it, certainly not 6+ billion of us, many living in large cities near the ocean. Another is, these large climate changes were also associated with large extinctions. We might not want to cause climate change sufficient to drive a large extinction. During the glacial to interglacial warming 10-18,000 years ago, global human population was likely only a few million, and were largely nomadic. So when climate got bad in one area, they simply moved (or died). Today, with 6+ billion people occupying the earth in stationary cities, it'd be difficult to move out of the way if climate got bad where you were.

Perhaps the strongest indicator of our time scale of concern is human life. If change were to be small over 70 years, we might not be concerned as little would be different between our birth and death. More quickly, we might want to ensure that there was reasonable stability between the time our kids were born and the time they reached adulthood, 20ish years. Given the two, 'a few decades' becomes our time range. Cities also point us towards the few decade time scale -- it is on this scale that urban infrastructures are built and rebuilt. If changes are slow enough that 'all' we have to do it rebuild the city further inland over the next 50 years, for instance, then relatively simple practices could get us there (but this would require some consideration on how to carry it out, as people who live now in the area marked not to be rebuilt might object!).

So, while I'm very interested as a scientist in, for instance, the 100,000 year cycles of the ice ages (my first scientific paper was on it), it's just too slow to be a concern to me as a citizen. As a citizen, I'd as soon that scientists did understand the 100,000 year cycle -- the more that is understood, the more likely that good estimates can be made of the futures. But the estimates that matter are those for the next few decades to maybe a century or two.