Thursday, 1 May 2014

My expert prediction

As I have noted in the past, scientists excel at projecting an image of wisdom. Since the general public rarely meet an actual scientist and see what they are really like, they have no reason to believe otherwise. So why don't people trust what scientists say? What happened to good old-fashioned blind faith? Are you seriously telling me that all those charlatan medieval priests pulled off a more convincing act than modern scientists? It surely can't be enough to simply deliver to people your pronouncements from within imposing architecture while wearing long robes, in order to poison their minds, take all their money, and bugger their children.

And, no, it's not because the scientists say things people don't want to hear, or repel them with alarmist predictions. Yeah, right. When the climate scientists say, "Please ride your bike more often or the weather will get bad," that's just too much to handle. But when a priest says, "Don't drink, don't gamble, don't screw, or you'll burn for eternity," everyone cheers and flocks back next week, crying, "Please, take all of my meagre income, my immortal soul is more important than mere sustenance, and are you sure you don't want my youngest son for your bare-bottom choir?"

There are many wise scholars of human history, culture, and psychology, who can offer a host of plausible explanations for why scientists don't get universal respect and adoration, but I would like to suggest one aspect of the problem that they may be reluctant to mention: it could be precisely the continuous chattering of these experts that gives real scientists a bad name.

When most people think of an expert, they mean someone who appears on a television panel discussion and makes confident predictions that are invariably wrong. Political experts told us in 1988 that Soviet communism was a permanent reality that we just had to get used to, and in 1990 they told us that Russia had a glorious democratic future ahead of it. Economic experts told us in 2007 that not only was property a fantastically safe investment, but we should also take advantage of all of the cheap mortgage options that were so readily available. It's not that there is something flaky about political or economic experts. The problem is that they are making predictions, and as deep and wide-ranging as their knowledge may be of political history and economic theory, or economic history and political theory, predictions are hopeless. Studies have shown that expert predictions are indeed better than those of non-experts, but the numbers are hardly inspiring: a random guess is correct 50% of the time, and the experts are correct 51% of the time (with a margin of error of 2.3%). Many people assume that the same is true for scientific experts.

But those were not scientific predictions. A good scientific theory is built from the results of reproducible experiments, and makes predictions that are confirmed by further experiments. If I tell you that the sun will rise tomorrow morning, that is based not just on the fact that it has risen on every single morning that anyone has bothered to pay attention, but also a mathematical model of the Earth's orbit around the sun, and the Earth's rotation, that is derived from an understanding of gravitation that has been rigorously tested and confirmed for hundreds of years. So I can tell you not just that the sun will rise tomorrow morning, but also what time it will rise in your neighborhood. The risk in trusting this prediction is negligible, assuming that I did not do the actual calculation myself. If someone is stupid enough to argue that it works differently, we could make ourselves a tidy fortune betting against them. (Amazingly, there do exist such dolts.)

On the other hand, I cannot so confidently predict that the sunrise will be followed by a broadcast of the BBC World Service. At the risk of upsetting die-hard British imperialists, I'm afraid that the BBC is not governed by a fundamental force of nature. It is instead run by a collection of people whose work may at any moment cease due to a surprise managerial decision, a collapse of government, or the revelation of a child-abuse sex scandal. These outcomes are not at all predictable (with the possible exception of the last), and a bet that the BBC World Service News will play at 6am tomorrow is fraught with just a little more risk than the previous dawn wager.

These fine philosophical distinctions are usually unimportant, because we know that non-scientific experts can be easily identified as the people who turn up on TV and argue with each other over whether Ukraine will be part of Russia by next Wednesday. On the other hand, scientific experts beaver away in complete obscurity, and do not need to be identified at all.

Now we get to the problem of climate change, where everything is turned upside down. Now the scientists have emerged blinking from their labs to go on television and argue with all the other experts. Given a good scrub and a new suit, they are difficult to tell apart. Even more confusing, they too are now making predictions that will affect economics and politics. And most disconcerting of all, they are missing their usual scientific guarantee. They have made models of what will happen to the Earth's climate if human activity continues unchanged, but humanity hasn't yet completed the experiment to verify that the models are true. Given the fallibility of human beings and the mischievousness of nature, there are sure to be many aspects of these models that are not true.

In this situation the correct scientific advice is obvious. It is this. "Please continue industrial activity at exactly the same level until the year 2300, so that we can properly calibrate our models. Then we would like you to revert to a pre-industrial, pre-agricultural, hunter-gatherer society. Don't worry, this may require no effort at all. Remain this way until all traces of modern civilization have left the land, oceans and atmosphere, which shouldn't require more than a few thousand years, although if you could spare ten million that would be really great, because there may be some crucial species that we'd like to re-evolve. Then could you please reconstruct all of your cities and factories and highways and commercial jet airliners, and we will predict for you the effect on the climate over the subsequent century. At that point we expect to know for sure exactly how human-made climate change works. Ideally we would like to repeat this experiment several hundred times, but we wouldn't want to try your patience."

For some reason people refuse to adopt this proposal. I don't know why the scientists don't just throw up their hands in despair. They would be entirely within their rights to conclude that any species that will not follow standard scientific procedures does not deserve to survive anyway. But instead they have done something quite different. They have asked themselves a wise and noble question, which is: "What would a Hollywood hero do?"

A Hollywood hero would take the laughably limited data to hand, concoct a brilliantly clever explanation of what's going on, and then declare, "I've got a plan! Everyone follow me! Trust me, I'm a scientist!" And their plan would work, and everyone would be saved.

This is what has happened with climate change, but on a scale where there are thousands of hero scientists. They have frantically collected all the data they can get, and made as much sense of it as they can, and announced, "Quick, follow us! This is our only way out!"

Unfortunately not everyone has followed the script. "Well, well, well," say the politicians and policymakers and pundits. "This is highly unorthodox. We're not sure whether we should follow you or not."

Should they? You can guess what my opinion is, and I'll explain why next time. It might even be the end of this interminable succession of posts on climate change. But don't bet on that prediction.

Next: Free thinkers, blind sheep, and bloodletting.


  1. ”…it could be precisely the continuous chattering of these experts that gives real scientists a bad name…”

    Sounds reasonable. I followed your there do exist such dolts link and found myself reading this: “The Principle” features… commentary from prominent scientists including George Ellis, Michio Kaku, Julian Barbour, Lawrence Krauss, and Max Tegmark. Ooooh, Mark!

    Aw, don’t worry about climate change. An expert told me that something called a pan-dem-ic will fix all our climate change problems at a stroke. Oh and meanwhile, I hear that all current Ernie Rutherford fellowships are to be terminated in favour of new fellowships dedicated to climate science.


    1. I apologize for assuming that the noxious fraudulence of this movie was blindingly obvious. Maybe this link would have been clearer.

    2. It was blindingly obvious, Mark. No apology necessary. Peter Woit covered it back in January.


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