Rush Limbaugh Plays Bait-And-Switch With Computer Models, To The Listener's Detriment

Listening to the radio this morning, I heard Rush Limbaugh lambasting environmental 'wackos' again. Apparently 'flawed computer models' are to blame for shutting down that economic powerhouse, the European aviation industry. People are 'going broke', stranded unexpectedly as they are in expensive locales, at the mercy of ruthless hotels and restaurants.

What is Rush talking about? What 'flawed computer models'? Based on previous Rush tirades, the listener is left to presume that the 'flawed computer models' are the same ones that provide estimates of global warming due to greenhouse-gas emissions.

So, in order to check Rush's sources, I had to go where I hate to go these days, where I go only every six months, or so, since it's no longer privy to White House gossip anyway, but where all conservative media folks nevertheless still get their talking-points for the day: Drudge.

Drudge referred me to this article, which sheds more light:

Flawed computer models may have exaggerated the effects of an Icelandic volcano eruption that has grounded tens of thousands of flights, stranded hundreds of thousands of passengers and cost businesses hundreds of millions of euros.

The computer models that guided decisions to impose a no-fly zone across most of Europe in recent days are based on incomplete science and limited data, according to European officials. As a result, they may have over-stated the risks to the public, needlessly grounding flights and damaging businesses.

It is a black box in certain areas,” Matthias Ruete, the EU’s director-general for mobility and transport, said on Monday, noting that many of the assumptions in the computer models were not backed by scientific evidence.

European authorities were not sure about scientific questions, such as what concentration of ash was hazardous for jet engines, or at what rate ash fell from the sky, Mr Ruete said. “It’s one of the elements where, as far as I know, we’re not quite clear about it,” he admitted.

He also noted that early results of the 40-odd test flights conducted over the weekend by European airlines, such as KLM and Air France, suggested that the risk was less than the computer models had indicated.

The acknowledgement that the computer models were flawed is likely to provide ammunition for critics who believe that authorities have shown excessive caution. The closure of much of the airspace over Europe over the past five days is estimated to have cost airlines a total of $200m a day in lost revenue.

Mr Ruete’s comments highlight the lack of technical expertise that has hamstrung European policymakers as they try to manage the consequences from a rare act of nature. Mr Ruete compared the scenario with his work in the 1980s trying to assess health risks after the Chernobyl nuclear accident.

He also urged European officials to consider adopting US aviation standards.

“If you take the situation across the Atlantic, there the advice would probably be: don’t fly over the volcano. Otherwise, it is up to you to take the precautions necessary,” Mr Ruete said.

While the US system leaves air carriers with the responsibility to determine whether or not it is safe to fly “the American model is not a model of less safety”, he said. “You just need to look at the statistics to see that.”

Under European rules, member states have the power to decide whether or not their airspace should be open. But decisions during the past week have been guided by computer models from the Volcanic Ash Centre in London and Eurocontrol, an organisation that co-ordinates air travel.

European safety procedures on volcanic ash were put in place after two incidents involving British Airways and KLM jets in the 1980s, in which aircraft engines lost power after flying through ash above Indonesia and Alaska.

In the wake of those events, the International Civil Aviation Organisation, a UN body that sets flight standards, asked air traffic controllers to develop contingency plans. Under these plans, the presence of ash prompted airspace to be restricted.

Ah ha! The problem is not 'flawed computer models' after all! Certainly not the same ones that provide estimates of global warming due to greenhouse-gas emissions!

The problem seems to be two-fold: lack of information about the 'safe' level of volcanic ash concentration, and lack of information about the ash itself: height, size distribution, rate of fall, and the like. The best computer models ever devised are going to stumble if the information upon which they feed is flawed, or incomplete. The models aren't to blame: it's the inadequate information upon which they are being forced to rely.

So, understandably enough, in the absence of reliable advice, European authorities are being quite conservative about taking risks with lives and aircraft, and shutting down vast swaths of airspace. And don't be misled by the article, which seems to assume American aviation authorities have a much more gung-ho mentality about the safety of flying through volcanic ash than Europeans do. If Mount Saint Helens blew it's top again, American authorities would act exactly the same way European authorities have been acting - with extreme caution. There is just too much at stake!

There is a real lack of understanding of the interaction between volcanic ash and aircraft. What people do know is pretty sobering. Suspended pumice can fuse onto turbine blades, thus damaging them in flight. Aircraft that have flown into thick volcanic ash by accident, generally at night when the plumes can't be seen, have suffered engine shutdowns. All these aircraft have been able to restart their engines - thank God! - but there is no guarantee they can do so. Nothing like the excitement of restarting damaged engines on an airliner plunging to Earth! And there is precious little laboratory or field experience to decide what a 'safe' concentration of volcanic ash is. Computer models have to be guided by something, and if that something isn't there, you have a problem.

Rush deliberately misleads when he slams 'flawed computer models'. Not the first time, either, or the last. His favorite targets are climate scientists and environmentalists, and he would rather have people scoff in know-nothing ignorance at all computer modeling rather than have to listen patiently to the best-available (if sometimes hedged and inconclusive) qualified technical advice. And what does Rush care about European aviation anyway? Is he flying to Europe soon? Nah!

(But remember, Rush does like to fly to the Caribbean a lot, and they have volcanoes down there too. We all have some stake in a good answer to aviation's problems - even careless and flippant Rush.)