Monday, April 19, 2010

Precautionary principle and flight bans

The Eyjafjallajökull volcano eruption (I want to make you sure that your humble correspondent can copy-and-paste the word, too!) has led to a flight ban over much of Europe that has been obeyed for several days. Some countries such as Czechia re-opened their airspaces today.

The weather and the visibility during the weekend were just great and it looked kind of absurd that the flights were banned. But was it really absurd?
Play a Flash game in which you are the volcano trying to shoot down the airplanes.
The airlines have been losing approximately $200 million per day. That's a lot but it's not an infinite amount of money. A part of this loss was happily earned and therefore "compensated" by the railways that have seen a visible increase in the demand for their services. ;-) After all, Czech President Klaus (and the prime minister and Prague's Catholic Archbishop) had to take a train to Lech Kaczynski's funeral, too.

Nevertheless, this financial loss of the airlines - which has already exceeded the impact of flight bans after the 2001 terrorist attacks - is by far the most significant consequence of the recent average volcano eruption. I can assure you that the changes of CO2 or the temperature are negligible in comparison.

By the way, the E-word volcano started to produce less ash and more lava which is good. As soon as all the debt of Iceland is forgiven, the Icelanders will turn the volcano off. After all, 75% of the debt has already been paid: the Britons demanded cash and they have already received ash. :-) The remaining 25% can't ever be returned because the Icelandic language doesn't have any "c".

The airlines such as Air France, British Airways, KLM, and Lufthansa have performed their own tests - they have sent several aircraft directly through the ash clouds - and they have found no measurable impact on the aircrafts and engines whatsoever. It is not shocking that they're urging everyone to lift the ban and the EU officials could actually agree.

However, it's also true that NATO claims that the ash clouds recently damaged the motors of several F-16 fighters, a statement I can't independently confirm and that can be specific to F-16 whose speed can reach 1.6 Mach (multiples of speed of sound) i.e. 2,000 km/h.

The Prison Planet and The Telegraph's articulate and insightful writer, James Delingpole, have been thinking about the precautionary principle in this context. They're mostly making fun out of it and I think that they surely have a point.

Do I think that the ash can be dangerous all over Europe? Well, I have serious doubts about it and the experimental tests seem absolutely essential as tools to establish the existence or absence of a real risk. $1 billion per week is enough money for us to check whether we don't believe a superstition. In Iran, senior clerics believe that earthquakes are caused by prostitutes i.e. by women without any burqa but the Western countries may prefer a different approach to science and policy. :-)

Why do I find the danger hard to believe? Well, you need to look at pieces of dust that are able to stay in the atmosphere, ten kilometers above the ground, for several days. I tend to believe that to stay in the air for such a long time, the ash must be composed of pretty small and light particles. And after the days, the concentration becomes pretty small, too. So it just seems unlikely that it can damage such big machines.

I would even guess that things like insect may have a bigger impact.

Very soon, we will see how the regulators decide about the airlines' protests. I would like to stress that the airlines have no interest to do "more dangerous things" than others. After all, air accidents are bigger problems for the airlines themselves than for anyone else! They surely have no financial motivation to be killing the passengers. So I would kindly leave most of this risk assessment to their own experts.

Note that the ban has only lasted for several days and it has only affected one small portion of the economy on one half of a continent. Still, people are nervous, tens of thousands of people are stuck at random places, while lots of investors are worried about their lost profits and possible bankruptcies.

Now, imagine that some people effectively want to impose similar bans that would affect the whole economy of the entire world for decades - or forever. This clearly can't work.

As soon as people start to be affected - to the extent that the CO2 production will significantly drop below the levels that the nations could afford economically - you may be sure that people will start to realize that the economy-wide carbon regulation is a complete insanity or a crime and the people who have actively helped to codify it - and fill their own pockets with money along the way - should be put in jail or executed.

The only reason why we're not there yet is that there's been no "successful" reduction of CO2 emissions caused by any of the policies so far. But make no mistake about it, the proponents of carbon regulation are playing a very dangerous game with their own lives.

And that's the memo.


  1. I don't think you understand how important this is. The world's supply of premium Scotch, shipped by air, and been interrupted. This is a true disaster for Scotch drinkers.

  2. Lost here are the second order consequences. Mortality rates for car travel per mile are far higher than for air. Risks are not avoided by the flight ban- they are transferred. We are actuality trading possible air flight risks for known car travel risks.

  3. Since aircraft have been flying around volcanoes for decades, not to have threshhold levels (say, 100ug per cbm continuous; 1mg per cbm not exceeding one hour; 3 mg per cbm not exceeding 2 minutes etc) is unforgivable. This is therefore simply an ‘own goal’. It is negligence by the regulators (not only financial regulators guilty of this, then).

    This is a self-generated problem. There was, after all, an International Symposium on Volcanic Ash and Aircraft Safety, in Seattle in 1991 NEARLY 20 YEARS AGO, see here for Proceedings:

    The paper by Przedpelski and Casadevall states:

    “The greatest threat to aircraft and engines is presented by “new” clouds (within hours of eruption) that contain large concentrations of ash particles…The ash particle size distribution in volcanic eruption clouds should be documented. In addition, engine and (or) combustor tests should be sponsored by the Federal Aviation Administration (FAA) to establish threshold values for “safe” levels of ash concentration and the “safe” range of combustor temperature. This information, combined with updated dispersion and theoretical fallout models (and with improved cloud tracking) can establish when an ash cloud ceases to be a flight hazard. These efforts will enhance aviation safety and reduce air traffic delays resulting from volcanic activity.”

    Let’s face it, the regulatory authorities and the engine manufacturers have had decades to perform actually very simple and controllable experiments, and so enact the recommendations from the international symposium. I have no idea whether they did so – it appears that they focused on detection and avoidance rather than thresholds, and so we have the unacceptable situation we have today. The same type of thing occurred when London had an unexpected snowfall in 2009: not a single London bus ran that day. Strangely enough, this sort of invocation of the precautionary principle (if in doubt do nothing or shut everything down) is nothing more than a cop-out, and it is interesting to note that the more businesses are required to do ‘risk assessments’ the more the precautionary principle is employed, not the less. Risk assessment today seems to be more a process of risk identification and avoidance, giving more and more excuse to shut activities down rather than properly manage the risks.

    If the authorities have not actually performed the relevant experiments to determine what ash concentration thresholds are commensurate with acceptable aviation risk (say, similar to other risks) – experiments that CAN be done in the lab on multiple engines in controlled conditions – and ESPECIALLY after that International Symposium 19 years ago, then they have saddled the world with the problem we are facing today. The fact that so many seem to want to avoid doing properly conducted experiments with copious real world observations with robust physics is a drift back to the Aristotelian method where dogma, theory and dialectic took the place a proper evaluation of the real world. This is where we have arrived at in climate science, to a large degree.

    This is a complete fiasco that could have been avoided by the application of proper scientific method.

  4. Dear Tregonsee,

    whether you were joking or not, I agree that the inability to export whisky is a big problem by itself. Add all the remaining products, and you will surely see a vastly bigger problem than the warming ever caused by all airplanes in the world.

    I completely agree that these numbers should have been known for a long time, and even media should have told us what the dangerous levels are, and what the actual concentrations are. We haven't learned anything. We can't even say whether someone has ever tried to answer these important questions - but it could be just a defect of the media and politicians, not of the researchers who may have such papers in their drawers.

    surprisingly, the mortality rate from airplanes is 50% bigger than that from cars (but, of course, much lower than from motorbikes). There are 1.3 deaths for 100 million miles via cars, and the number for airplanes is 1.9 for aircraft. Trains match cars, at 1.3, while motorbikes are 20+ times bigger, 31.3 deaths. At any rate, it's true that the risk for airplanes and cars is similar.


  5. The figure of 1.3 and 1.9 are for one million vehicle miles. The better number for evaluating risk is per passenger mile. Lets make an assumption there is 1-2 people in a car and one hundred in a commercial airliner. (Basically, when you ground an airline you need to put 50 to 100X more vehicles on the road--need to compare apples to apples)The risk to an individual makes air travel far safer than by car per mile traveled by the passenger. If you only use commercial aircraft and add in pedestrians killed by cars the disparity becomes even larger.

  6. Dear Lubos,

    There's either a misprint or a true denominator problem in the table in your link ... trains are shown per million miles, the rest for 100 million miles.

    Makes me wonder about the denominator for cars, also, since the reference itself states that planes are a lot safer.

    And your blog is absolutely great! Thank you for all the time you put into this.

  7. The number you cite for 1.3 and 1.9 million are for vehicle miles. Passenger miles are more representative for individual risk. One can assume there are 1-2 passenger per car and 100 for a commercial airline. Airline as a method of travel is therefore an order of magnitude lower than automobile travel.

  8. Oops, you seem to be right. It's vehicle miles, so passenger miles make it safer. A month ago, I gave this misinterpretation of mine to someone's diploma thesis. ;-)

  9. The MET office is getting stick from EU officals for over forecasting the extent of the cloud. A telling coment was that they should rely on actual data as opposed to computer models which have been now demostrated to be wrong. Question is how long these EU officals will take to realise this opinion also translates well to AGW once you properly take into account UHI.

  10. IMO we should be taking this opportunity to fly a lot of old planes through the edges of the affected region. This'll give us data on what levels and sizes of particulates are //really// dangerous to aircraft engines.

    The data may not be available in time to help us this time round, but it means that we'll have a better idea of how to react the next time this happens.