Facing the Heat

 

I have been recently asked on a Mensa discussion list to comment on climate change. Can we all get it together before we fry?

Long-time readers of this blog may know my position on this.

The concept of global warming, or climate change, is based on expert predictions of the middle to distant future, using computer models.

The important thing to understand about computer models is that they are only as good as the data and assumptions: GIGO, as computer programmers used to warn the overly-reverent.

The important thing to understand about expert predictions of the middle to distant future is that they are usually wrong. Studies show they are less reliable than random chance, than flipping a coin, or than asking the average man in the street.

There are reasons for this. In the real world, most times, things go on as they have been going on, in more or less a straight line on a graph, or with regular oscillations, without changing radically. But if an expert says this, it has no news value. Nobody will be very interested, and nobody will see much use in their expertise. If, on the other hand, they forecast a dramatic change coming soon, it attracts attention—it attracts business.

Better yet if they forecast a pending catastrophe, that can only be averted by strenuous investment in their special expertise.

So there is a built-in incentive to forecast outcomes that are worse than what is likely.

This is reinforced by the human tendency to forget any dramatic predictions that did not come true, and only remember those surprising ones that did. So experts can afford to be wrong, repeatedly. Astrology works the same way.

Back in the Sixties, the experts were telling us we were going to run out of food and clean water within twenty years. In the Eighties, we were less than a decade away from “peak oil,” and a collapse of the world economy from a lack of energy. Also in the Eighties, we were all going to die of AIDS. Remember the hole in the ozone layer? The sky has been falling for a very long time.

The really dire predictions about global warming may be true, but what are the odds?

The thing we call “climate change” or “global warming” is a set of assumptions, not just one. At least, if you reject any one of them, you are a “climate change denier.” We do not have the expertise nor access to the data to evaluate these for ourselves; we must rely on experts.

1. That the earth is getting warmer year by year.

2. That this is on balance a bad thing.

3. That human beings can realistically do something about it.

4. That the cost of doing something about it is less than the cost of letting it happen.

5. That we, as individuals or as a nation, can realistically do something about it.

6. That some technological advance will not eliminate it without government intervention.

Now let’s put aside the observation that expert predictions are usually wrong, and just give them all fifty-fifty odds. Then, for all of them to be true, the odds are 1.5 out of a hundred.

How much money are we prepared to invest on a 1.5% chance of coming out ahead?