Scientific advice and evidence in emergencies - Science and Technology Committee Contents

Memorandum submitted by Professor W P Aspinall (SAGE 19)

  I am responding to the committee's invitation for written submissions on the issues identified in relation to their inquiry into scientific advice and evidence in emergencies.

  I am a consulting Chartered Scientist and Cabot Professor in Natural Hazards and Risk Science at the University of Bristol. My comments are informed by my experience as a member of the Foreign Office Scientific Advisory Committee on Volcanic Activity in Montserrat, as a member or the CSA's advisory group SAGE on the recent Icelandic volcanic activity, and my other professional experience in relation to hazard assessment and risk assessment in safety critical industries, flight operational safety and medical issues requiring expert judgment. These comments are made on a personal basis and should not be construed as representing the views of any organization, institution or committee with whom I had been associated.

  Before making some generic comments, I will provide brief responses to the five points identified by the Committee in relation to the four case studies they are considering. In the main, my responses relate to the Icelandic volcanic ash eruption in April 2010.

    1. The hazard created by the volcanic eruption was airborne ash, which entered UK and neighbouring airspace, and the two main risks were (a) risks to flight safety (airworthiness), and (b) operational disruption. Having been one of the people called in to provide advice to SAGE, it was clear that the UK government was little prepared for this emergency.

    2. In this case, and in the case of the ongoing eruption of the Soufriere Hills volcano on Montserrat, which started in 1995, there was little if any preparation for such an emergency and the government's response was, therefore, almost totally reactive. For instance, in the case of the Montserrat crisis, the setting up of a formal scientific advisory committee to provide advice to the FCO was done at the instigation of scientists involved in monitoring that crisis, and not as initiative of government itself.

    3. Unquestionably the government has sufficient powers and sources to overcome obstacles, but an efficient and unambiguous framework for obtaining reliable timely scientific advice and evidence to inform policy decisions is not well established within government. Moreover, in the case of the Icelandic ash crisis this year, there was a signal absence of will to fund support for urgent work to be done in the universities, in the British Geological Survey, or by other outside specialists in industry and consultancies with significant relevant experience. The imminence of a general election seems a very questionable and lame excuse for failing to properly mobilise and support vital hazard and risk appraisal work for an emergency of such massive economic impact, and one with a residual potential for mass casualties when some airlines started operations while conditions were still uncertain.

    4. Strategic coordination between government departments, public bodies, private bodies, sources of scientific advice and the research basis has not been and is not fully effective in preparing for or reacting to emergencies. A major problem, which was manifest both in the recent Icelandic crisis and in the Montserrat crisis, was the failure for one department in government to take full ownership of the "problem"; in the case of Montserrat, there was (and still is to some extent) a continuing division of responsibility between the FCO and DFID, despite a Select Committee recommending that one or the other take control of the crisis after people were killed in 1997. In relation to co-ordination between government and specialists other than those in the government service or in universities, successful working relationships are, not unnaturally, difficult to establish in an emergency—prior liaison, breaking down silos and barriers, invariably produces dividends, and the benefits can be attested to from many other emergencies.

    5. International coordination is very important with respect to volcanic activity, and although the UK itself has significant—possibly world-leading—volcanic risk assessment and crisis management experience from the Montserrat eruption, international collaboration is essential—such activity can be very complex, is not confined to national borders, and needs the best expertise for handling the many-faceted aspects of the threats. This said, there have been some obstacles to strengthening such collaboration imposed by the UK government: for instance, an invitation was extended to me as a volcanic hazards specialist to attend a major volcanic emergency exercise in Italy a few years ago, but the invitation was not acted upon officially simply because I was not a government employee—and this despite having sat on the Montserrat SAC since its inception!

  Moving on to more generic issues, any decisions in relation to emergencies arising from the sorts of situations mentioned in the Inquiry need to be "risk informed" to the maximum extent possible. For the best and most defensible policy decisions to be made where scientific uncertainty is a key factor, comprehensive quantitative risk assessments (QRAs) are needed. One thing that has struck me forcibly has been the limitations in the extent and detail of application of good practice QRA principles to the Montserrat and Iceland eruption scenarios, when compared with the rigorous and exhaustive assessments undertaken in this country for, say, external hazards to nuclear power stations, for instance. [As well as participation in the two volcanic crises at issue, I have been involved also in UK nuclear safety work for more than 25 years, sit on various IAEA hazards committees, and therefore have a wider than usual perspective on the issues].

  The present selective scenario-based approach for risk appraisal for national contingency management, such as has followed on from SAGE deliberations over the Icelandic ash crisis, is unable to capture all the intrinsic variabilities in volcanic processes, and I think it fair to say that nearly all, if not all, of the volcanologists involved in SAGE were dismayed by the approach that has been taken. The point here is that identification and quantification of uncertainties are absolutely key—uncertainty in relation to the true strength of contributory factors and, in particular, those which can be described as having heavy or long statistical tails, can drive up the estimated level of hazard, and hence risk. If these uncertainties are not adequately captured or otherwise are under-stated, there is the prospect of events happening that lead to major surprises, sometimes involving situations falling outwith the scope of policy decisions that were intended to deal with all eventualities.

  In this regard, the approaches to the Soufriere Hills volcano and Icelandic ash crises were ad hoc and insufficiently formalized, in my view. Such events may be very low probability but the consequences can be major, either in terms of calamitous loss of life or disastrous economic costs (or, indeed, both). The pathway from scientific uncertainty, through judgment to advice and thence to crucial decision-making should be made as explicit, auditable and traceable as possible. In essence, a simplified approach was adopted in both cases, contrasting with the sort of "scorched earth" risk assessments that are customary for major safety-critical industries. In both cases, the spectrum of expertise that was mobilized has been limited—for the recent Icelandic ash episode, academics, government agency staff and others acted on a pro bono basis, and a whole range of other expert knowledge and professional judgment, that exists in other domains, was effectively eschewed. In the Montserrat case, the risk assessment work has also been done on a shoe-string and, in many ways, it has been a matter of good fortune rather than sound mitigation that no one there has been killed or injured since the fatalities of June 1997 [ n.b. also there have been at least three significant civil airliner ash encounters near Montserrat during its fifteen years eruptive activity].

  In the case of the Icelandic ash crisis, one important consideration is the very high level of safety that is achieved in normal operations by the civil aviation industry. The occurrence of extraordinary and highly unpredictable scenarios—involving extensive volcanological uncertainty and meteorological variability, and contingent engineered system impact uncertainties, such as ash-induced engine failure modes—can easily produce a situation where margins of safety are (or might be) eroded to the extent that, inevitably, such reduction, perhaps tolerated unwittingly, could appear indefensible post hoc, if disaster ensues. In this particular case, I was concerned in SAGE that there was no comprehensive end-to-end uncertainty/hazard/risk assessment with which to inform the urgent decisions being made; a detailed and thorough assessment was required that needed much more attention to detail and much more effort than was possible under the imposed ad hoc conditions. As the economic costs of the flights disruption were massive, even a major cost incurred in producing better hazard and risk assessments would have been justified, in this case at almost any imaginable cost—especially given the possibility that such advice, if well-founded, could have been used to sustain, at the earliest possible opportunity, a restart of flights on a reasoned evidence-supported basis. The impatience of some airlines to get flying again was not properly evidence-based and hence not completely rational in the circumstances, but this could happen because no one government department seemed prepared to grasp the nettle and contemplate all the issues fully and with funding support.

  This latter point, about when an emergency can be considered ended, is important: it is a common feature of many unusual threats, such as a volcanic eruption, solar storm or pandemic, that determining when to declare a crisis over is frequently much more difficult than raising the alert in the first place, when things are obviously escalating. Premature decisions in sounding the "all clear" can incur unintended risks—having successfully negotiated previous, on-going activity, declaring a false dawn can be disastrous. Avoiding this pitfall requires a significant measure of expert judgment and a judicious way of acquiring it, under pressure.

  Thus one element in the provision of sound scientific advice to government in response to national emergencies, which calls for some new thinking, is finding an optimal structured procedure for the elucidation of expert opinion to derive a rational consensus as the basis for decision support. My professional experience in this regard includes facilitation of performance-based (ie scored and differentially weighted) expert elicitations for forecasting and mitigating volcanic eruption scenarios, for ranking and managing flight operational safety issues, and for modelling emergent virus and other medical challenges [eg SARS risks to health workers; vCJD risks from blood products; emergence of the XMRV virus, a gammaretrovirus first described only in 2006, with potential associations to chronic fatigue syndrome and prostate cancer].

  It seems to me that adopting this formalized approach to expert judgement—when the circumstances are appropriate—would be a valuable addition to the toolkit of decision support techniques, especially in the matter of quantitative risk assessment in the face of significant scientific uncertainty. In addition, there are available nowadays useful (Bayesian) graphical techniques for weighing and combining different strands of uncertain scientific evidence, so that the import of such evidence can be thoroughly and efficiently adduced for decision support. It also seems clear to me that further work is needed to establish government-spanning protocols and a decision framework for accessing scientific advice and scientific evidence in emergencies, and for utilizing the best techniques and methodologies—bearing in mind the latter is an evolving domain that warrants those involved keeping current with developments. Again, reliance on outmoded, inferior or casual approaches can expose government to censure if things go pear-shaped.

Professor W P Aspinall

13 September 2010

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