Former government minister Claude Allègre is once more to be hailed for fighting the “consensus”, as his recent book is high on the best-seller lists.

Yes, discussion is possible; no, scientific progress is not a matter of international voting to find the truth. (This would be comparable to letting the dictatorship countries vote on human rights at the UN; sorry, my mistake, they already do that.)

As the late Aaron Wildavsky would have said, what counts in today’s debate is not rational evaluation of risk; but instead the potential catastrophic impact of largely theoretical and infinitesimal hazards. What if the tap water in Paris causes cancer? What if antennae for mobile phone networks pose serious health risks?

Where is the proof? “We’re not talking about risk calculus, but about the potential damages”, argue the precautionary zealots. But with an unqualified “if”, anything is possible and all potentially dangerous activities must come to a halt, as the recent Icelandic saga showed. Allègre points out that the decision to block air traffic worldwide was based on a theoretical model which had never been tested. This also applies to other recent health scares (eg bird flu, H1N1 …)  Sounds familiar?

Dealing with the future implies collecting the unknown by small samples, ie through scientific research, experiments entailing trial and error to gather more knowledge. There can be no insurance policy against uncertainty, and hence no “trial without prior guarantee against error”. Yet politics thrives on this need to peddle government-based certainty in a chaotic world.

We need to distinguish between probabilities and calculated risks. The first is basically speculative by nature and only the second may form a reasonable basis for policy action. Panic-mongerers will prosper by selling disaster plans to the public and decision-makers. But our governments would do better to join the cooler heads coalition. Lest we all die in fear of the unknown, in order to reach certainty at last.