« | Home | »

The Precautionary Principle

Tags: |

In recent times the usual response to scientific uncertainties about risk has been to apply the precautionary principle. Action is taken to prevent potentially dangerous events when there is no robust evidence about their likely magnitude, or sometimes even about the likelihood of their occurrence. With both Eyjafjallajökull’s eruption and swine flu, pessimism and a heavy reliance on a very small number of historical events drove the policy response. It is on record that major damage has occurred on the few occasions when planes have flown through thick volcanic eruptions. In the century before swine flu there were only three flu pandemics, in 1918, 1957 and 1968. So when the precautionary principle led to the roll out of planned policies – zero tolerance for ash and very vigorous controls for the newish flu virus – the science was very imperfect. There was no data about whether a thin cloud of volcanic ash invisible to pilots was dangerous, and it wasn’t possible to predict from its gene sequence how dangerous a new flu virus was going to be.

The preventative policies were overenthusiastic. The policy reversals both on flying through thin clouds of volcanic ash and on swine flu (vaccine orders have been scaled back and the tamiflu hot line is closed) mean that there will be recriminations. It will be said that lessons must be learned. Rather than blaming regulators or scientists, the right response should be to say that a reaction to events that relies on the precautionary principle is probably going to be wrong. The onus is on the policymakers to fund the scientists to get the evidence to make it right.

Comments on “The Precautionary Principle”

  1. Phil says:

    when there is no robust evidence about their likely magnitude, or sometimes even about the likelihood of their occurrence

    I think this point – and the difference between risk and uncertainty – could be stressed more strongly. If you can estimate the probability of an event occurring, and you know how the severity of its effects when it does occur has been distributed in the past, then you’ve got a calculable risk and the rest is more or less arithmetic. If you haven’t got a distribution for the severity of the event’s effects or you can’t estimate a probability for it occurring, then you’ve got no usable numbers and you’re in the realm of uncertainty. And, as much as I hate to agree with Dick Cheney, it seems to me that in potentially dangerous situations characterised by uncertainty the precautionary principle has a lot going for it.

    I agree in principle that reducing the uncertainty is a much more cost-effective (and sensible) approach than building up the precautions, but it’s also a much longer job – and these threats do sometimes blow up out of nowhere, as Eyjafjallajökull rather vividly demonstrates.

  2. Camus123 says:

    This all seems to me to show that enlightenment and making nature do what we want has reached the end of the road.

Comment on this post

Log in or register to post a comment.


  • Recent Posts

    RSS – posts

  • Contributors

  • Recent Comments

    • suetonius on Remembering Seymour Papert: Oh my, flashback inducing. I remember being an undergraduate right when the book came out, physics student at the time. Several of my professors wer...
    • fbkun on Justice for Théo: Polls show that more than half of French police(wo)men vote for the Front National. Quelle surprise...
    • jcscott on The Deep State: How we get rid of Trump is at least as important as whether we get rid of him. The best would be a progressive landslide election in 2020 repudiating ...
    • Oliver Miles on Shambles in Court: A very difficult problem, almost insoluble. Many people are quite unaware of it and just assume that if there is an interpreter there is no problem. I...
    • michael bosley on Arguing with Strangers: Meanwhile, in the UK, cuts in sexual health services are being made by stealth, with hardly any public/political debate. As a report by the Advis...

    RSS – comments

  • Contact

  • Blog Archive

Advertisement Advertisement