Citation: Pichl, H. (1997) Basic philosophy for environmentalists. Verge (Amsterdam) (ISSN: 1384-7392), June, 24–25.

Basic Philosophy for Environmentalists

It can be quite useful to know some basics in philosopophy when discussing the relationship between science, politics and society. As an example, I want to quote a geochemist who recently told a Norwegian newspaper that: (a) it is not finally proved that global warming is caused by human activities; (b) politicians who believe in such "prophecies" are victims of an "opinion dictatorship"; and (c) it has been much warmer in earlier times.
We shall now see how easy it is to refute that geochemist with philosophical arguments alone, even without knowing much about the scientific facts involved. But first, we have to have a closer look at some philosophical background knowledge.

Lesson I: Popper
It was Sir Karl Popper, the Austrian-British philosopher of science, who concluded that "the logic of scientific discovery" (as he called his first book) is based upon rejection of hypotheses alone. That is quite an important point because it means that science cannot prove hypotheses.
According to Popper, progress in science looks like that: a scientist proposes a new hypothesis, the more radically different from older hypotheses, the better. Then, the "scientific community" puts all its energy into falsifying the hypothesis, that means to prove it to be false. The longer they try without succeeding in that goal, the "better" is the hypothesis. But never ever will the hypothesis get the label "true".
A well-known example is the one with the black ravens. How many ravens do I have to observe in order to prove the hypothesis that "all ravens are black"? The answer is: no matter how many observations gave support to the black-raven hypothesis, it won’t therefore be proven true – simply because I might observe a yellow raven just the next morning. Then – with only one observation that does not fit the hypothesis’s prediction – the hypothesis is falsified, and science has made progress (though, in this example, a modest one).
This – scientific – meaning of "proof" is unfortunately quite different from its every-day usage. We expect politicians to tell us, and courts to establish, the "truth". In every-day language this is perfectly understandable. What we mean is in a way slightly different: we want politicians (or defendants or anybody else) to tell us everything they know, not only that half of it that fits their personal aims.
It is, in other words, unscientific to demand a scientific proof that a certain action to be implemented by politics, is appropriate to solve the respective problem. Nevertheless, you often hear such demands: "we won’t set down speed limits on highways unless you can prove that this will make emissions decrease." Or, "we can’t shut down nuclear power plants before it is proven that we will have enough other sources of energy." You can support such statements with strong evidence, but you cannot prove them.
Anyway, it is strange that this demand is only heard when the action in question is against the interests of the industry. Did you ever hear a politician say: "I won’t build that highway unless it is proven that it will reduce traffic jams"? Or did you hear an industry manager proclaim: "I won’t move my factory to a country with weaker environmental legislation unless someone can prove that I really gain a net profit from it"?

Lesson II: Risk
Imagine a discussion of proponents and opponents of nuclear power. Arguments do mostly stay the same: environmentalists claim that nuclear power is dangerous, the industry insists on telling that the probability of accidents is unbelievably small. Obviously, we are confronted with two different languages, one group speaking of "danger", the other one of "probability". But there is a possibility of bringing the two together, namely by using "risk". The definition of risk is: danger times probability.
The manager of a nuclear power plant cannot counter the statement, "the risk of using nuclear power is too high", by saying: "but the probability of accidents is low". That is because probability is already included into the measure "risk".
But, consequently, it is also the other way round. You cannot counter the statement, "the risk of nuclear power is acceptably low", by saying: "but the danger is too great".
The only way to counter is: "acceptable to WHOM?"!
There are – fortunately or unfortunately? – no guidelines for which risks are acceptable and which ones are not. I will illustrate that in the third lesson:

Lesson III: Hume
David Hume, British philosopher of the 18th century, is known for his so called "is/ought dichotomy". That word means that you have to distinguish between "is" and "ought" statements. Particularly, you cannot derive them from one another. Facts are not normative. There is no fact that allows anybody to tell us what we ought to do (= what is morally right to do).
Take smoking as an example. Smoking is dangerous to people who actively or passively inhale smoke. But is it therefore right to say: "you ought not to smoke!"? Philosophically you have no right to do so. What you ought to do, is a question dealt with by the science of normative ethics, not by medicine. Medicine can make factual statements concerning the risks of smoking, but no more.
Let us apply these thoughts to environmental subjects: imagine a certain piece of land that is a virgin forest. This fact is, in itself, no reason to demand: "you ought not to clear-cut that piece of land". What you could say is: "one ought to preserve virgin forests, that piece of land is a virgin forest, therefore you ought not to clear-cut it." The clear-cutting company has then three possibilities to answer. First (preferably), "you are right". Second, "that forest is not a virgin forest". In this case you can go for the help of a scientist that answers that (in itself value-free) question. Third, the company can answer: "you are wrong, virgin forests ought not to be preserved." That’s worst. You can’t disprove that sentence. You can just try to convince the person, but you might fail.
Or, back to nuclear energy, science can supply us with facts about both danger and probability of nuclear accidents, such that the risk of nuclear power can be calculated. But science with its factual statements cannot help us in formulating normative statements. "Is the calculated risk too high to be taken", is a question science can’t answer.
So far I only showed, how you can’t derive normative statements. But how can you? I will take up this question in the next Verge.
For now, I will only mention the precautionary principle. The precautionary principle demands that you do everything to avoid that something dangerous happens. In the nuclear energy (or the virgin forest) example you might as an opponent argue:
"You never really know how far-reaching the consequences of an accident in a nuclear power plant (or of clear-cutting all virgin forests) are. Afterwards you might agree that those consequences were not worthwhile. But it is only now – before an accident – that you can stop it from happening."
That should be enough philosophy lessons for today. I just owe you an answer to the first example, namely how to counter the greenhouse arguments of the mentioned geochemist:

The greenhouse effect is unproven
(a) Right, the greenhouse effect is not finally proven. But there is more to it: the greenhouse effect is unprovable. As are all other scientific theories. There is some evidence for a human-made global warming. Of course there are other hypotheses explaining global warming, but the greenhouse effect has so far not been falsified, that is why we have to take it seriously. Obviously, the geochemist hasn’t heard of Popper.
(b) Politicians who believe in the greenhouse effect, are not following a prophecy, they are acting according to the precautionary principle. The probability that the greenhouse effect is a "true" hypothesis, is not 100% – but it will never be, no matter how long you wait for more evidence. And we have no time to wait longer because the danger of the greenhouse effect is too big. In other words: these politicians believe that the risk is too great to be taken. (By the way: were are those great politicians the geochemist is complaining about?) Obviously, the geochemist hasn’t heard of risk, nor of the precautionary principle.
(c) Yes, it has been warmer in earlier times, for example when the vikings lived. But other things were different at that time, too: the world population, for example. A higher sea level has much more serious consequences today, with not only coast regions densely populated, but also the regions behind. Vikings could simply avoid drowning by following the rising ocean, moving up the landscape. But what was possible for them, will provoke ethnic conflicts today. Obviously, the geochemist committed a simple logic mistake, deriving one statement, "X is ok under circumstance Y", from another, "X is ok under circumstance Z".

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