Climate change is a large pile of perverse partial differential equations and soul-withering thermodynamic modelling. It cannot be understood in layman’s terms, let alone popularized. This, I believe, is the core issue. Skeptics quite rightly want explanations that they can understand. We should give them such explanations. But we can’t. They don’t exist.
Original Finnish version: here
This idea was inspired by a blog posting in which a well-known Finn compared faith in climate change to a religion. [Finnish only] The posting was actually fairly neutral, although the author has elsewhere profiled himself as a climate skeptic. The article has been heavily lambasted by the Green community here, perhaps rightly so. Yet, I decided to turn the question around: what if he is correct, at some level? Among people who believe in climate change, how many understand at a deep level how climate change actually happens?
Here’s my provocative claim: none. Even more provocative: climate change scientists don’t understand either.
What does it mean to “understand”?
The operative word here is “understand”. What does it mean? A clichéd definition is that one only understands something if one is able to explain it to any layman.
Problem: no one is able to explain meteorology to any layman. No one is even able to explain it to himself. I believe I have some background to claim this. My minor subject at university was meteorology. My MSc thesis and PhD thesis were both partly related to meteorology. Yet, I’ve never actually “understood” meteorology.
I passed all the exams and was able to do most of the exercises. Yet if someone had asked me what I was doing, I probably could not have answered. There was no real need to do so; at the professional level, meteorology, like any other hard science, is mostly about doing the calculations.
What kinds of things can’t we understand?
Here is a concrete example. We know that it’s hot and rainy at the equator; dry at about 30 degrees latitude (for example, the Sahara at 30° North, the Kalahari at 30° South); and rainy and miserable at about 60° latitude (Finland). This is related to the so-called Hadley cell; air rises at the equator, subsides at 30°, and rises again at 60°.
The general principle is well known from observations. What causes it? A simple primer might be an eight-page summary from UWM, which has fifteen equations of which most are partial differential equations. However, it is too simplified to be considered a full explanation. In other words the model is too complex to be understood, yet too simple to be accurate.
I recall a personal anecdote related directly to the Hadley cell. With a few other students, I tried to find out “why” the air subsides at exactly 30°. Why not 15°, or 45°? We could find no one in the department of meteorology who could give a simple answer. Most likely, no one can. The explanation is in the equations somewhere, but it can’t be understood.
The Hadley cell is a simple and concrete phenomenon in climate science, almost a trivial one. If even such a simple phenomenon requires professional physics studies to be understood, and even a professional physics student cannot understand it, then how could a layman?
Can people learn to understand?
The climate-change-as-religion article had an important point [translation mine]: “First, the changes in the forecasts. It was easy to believe in climate change in the years when Finland had warm winters. The cold and snow [of recent years] had to be added in later by hand — or at least that is the impression one gets. To be credible, scientists need to make a forecast that over time would prove to be accurate, without a need to tinker with it all the time”.
Indeed. This is a perfectly reasonable thing to ask for. But it cannot be done.
Climate models, like all long-term weather forecasts, are probabilistic models. Such a model might forecast that there is a 30% probability of thunderstorms in southwestern Finland. Since thunderstorms are highly local, this forecast can be correct, yet it can be “wrong” everywhere. It is perfectly feasible to have three days of thunderstorms in a row in Turku, while Salo 50 kilometers away remains bright and clear all the time. The forecast is correct, but no one realizes it.
There is an excellent article on long-term weather forecasts (Finnish only) written by A-J Punkka, a meteorologist. He describes the same thing from the perspective of farming (translation mine): “A sesonal forecast says nothing about daily changes in weather, and in particular it says nothing about the real weather extremes. The forecast can thus be perfect, but a severe (but short) period of frost at the beginning of the growing season can damage crops badly”.
Punkka seems to be an optimist though: “The single most important factor behind the problems may be the fact that people have not been trained to understand these new types of forecasts, and are not used to them”. Perhaps people could over time be trained to understand what the scientists are saying?
I doubt it, even with respect to ordinary forecasts. People might understand the extremes. If the Finnish Meteorological Institute forecasts four years in a row that the midsummer holiday will be warm and sunny with 90% probability, and every time it snows, clearly there is something wrong with the forecasts.
Yet, the pain already begins at this point. Assume that FMI forecasts that midsummer in 2014 will be warm and sunny with 90% probability. Assume it snows instead. Did the forecast fail? No. One year gives absolutely no information about the forecast. FMI forecast a 10% probability that the summer would not be warm and sunny; perhaps 2014 simply was the one year in ten when that happened.
How would one explain this to a layman? It’s not possible. I couldn’t even explain it to myself. Even though I know all the facts, and understand the statistics, I would still end up cursing the clowns at FMI for ruining my midsummer celebration.
What’s the problem: heuristics
The human brain is not built to understand probabilities; it is built to survive in the wild. The mind uses heuristics, simple models that usually work, but have nothing to do with abstract calculations of probabilities. The dry but fun book by Kahneman&Tversky is full of examples. Even professionals in probability cannot handle abstract probabilities in real life, if they are unexpectedly faced with them.
People have a right to demand explanations that they can understand. In fact, one sign of a healthy society is that people demand understandable explanations rather than mindlessly obeying. It is tragic that such understandable explanations don’t exist in the absolutely crucial area of climate change.
What is to be done?
I have no idea. Perhaps it would help if we who do believe in climate change would admit that there is an “element of faith” in our belief. None of us has personally gone through even a small part of the scientific literature. In reality, we have to trust that the gurus who compiled the IPCC report knew what they were doing.
But is this “blind faith”, as denialists might call it? Not really. Anyone can get a PhD in physics, follow the literature, and try to understand the modles. Even though the processes cannot be “understood”, the mathematics can. All the information is available in principle, even if no one has a full grasp of all of it.
Also, science is a self-correcting process, and relies on constant criticism and reworking of theories. If a theory does not conform with the facts, it will eventually be changed. Of course, this means that scientists have to tinker all the time with their models — which is the accusation that was thrown. It is a no-win scenario.
I have also observed the scientific world from the inside, spending a few years in academia. The experience gives me a refreshingly cynical reason to believe that the scientific community is playing with open cards. As a general rule, scientists are so fractious and paranoid that a conspiracy would not remain secret for more than a few hours. If someone is given an opportunity to stab his buddy in the academic back, he will do so without hesitation.
The pettiness of the academic world is a key reason why I really cannot believe in a conspiracy, at least an organized one. This pettiness may however be difficult to communicate to the general audience.
Still, to the larger question — what to do when it is impossible to produce explanations that people have a right to expect — I have no answer.
Original Finnish version: here
Other posts on the environment (Finnish only): here.
