Risk Research ( Covello and Mumpower, in Cutter: Ch 3 )

1. Geography 106bHazards Risk Research(Covello and Mumpower, in Cutter: Ch 3) • history of risk • risk components • risk analysis • “acceptable” risk • risk perception • changing nature of risk Geog 2152

2. (extremely brief) History of Risk and Probability • probabilistic risk assessments are not a “modern” phenomenon • religious origins Arnobius (AD 4th C) – risk to soul based on moral conduct • Pascal (1657) – expected value of accepting Christianity outweighs expected value of atheism Geog 2152

3. (extremely brief) History of Risk and Probability Probability Theory • dedicated to understanding whether events are random or happen by chance VonBortkiewicz (AD 19th C) • first known application of probability theory • soldiers dying in Prussia from horse kicks random or due to negligence of soldiers • 10 years data (see further in lecture importance of event data) • conclusion = random; no disciplinary action required Geog 2152

4. Risk Components risk perception • risk as viewed by individuals/groups of individuals (e.g., laypeople, scientists) • subjective • no single replicable outcome • risk managers ignore risk perception at their own peril! Geog 2152

5. Risk Components risk communication • information exchange between risk managers and lay publics (you and me) • historically one way transfer of information from managers to lay publics • lay publics more involved in decision-making Geog 2152

6. Risk Components risk management • minimize threats from hazards • minimize damage from hazards • maximize safety • maximize benefits from hazards Geog 2152

7. Risk Components risk assessment • quantification of risk • specialized science • “objective” detached practitioners Risk = hazard (probability) * loss (expected) preparedness (loss mitigation) Geog 2152

8. Risk Assessment Three key steps assess (Kates and Kasperson, 1983): • What hazardous events may occur? • What is the probability of each event? • What are the likely losses created by the event. Geog 2152

9. Risk AssessmentExercise • Groups of 4 • 5-10 min discussion • You have been hired by the Institute for Catastrophic Loss Reduction to make a risk assessment of an ice storm in London, ON • What sorts of data will you need? • What basic problems do you expect in calculating the risk? 1998 winter ice storm Geog 2152

10. Risk AssessmentStatistical Analysis R = p * L • R = risk • p = probability of hazard occurrence • L = loss (e.g., health, economic) Assistance interpreting probabilities: • since cumulative probabilities sum to “1” can read each probability as a percent • e.g., 0.01 is something that happens 1% of the time • e.g, 0.5 is something that happens 5% of the time Geog 2152

11. Risk AssessmentStatistical Analysis r – risk for each loss probability (top to bottom): • £0 • £300 • £750 • £500 R = £1550 Geog 2152

12. Risk AssessmentStatistical Analysis r – risk for each loss probability (top to bottom): • 0 deaths • 0.006 deaths • 0.006 deaths • 0.003 deaths R = .015 deaths Geog 2152

13. Rare Events and Probabilistic Risk Analysis Event Trees • used when historical event database is inadequate (too small) • chain of events leading to disaster must be known • probabilities within the chain must be calculable Geog 2152

14. source: http://www.bhopal.org/whathappened.html Rare Events – Not So Rare? Geog 2152

15. Rare Events – Catastrophic It Happened in Bhopal – AlJazeera YouTube video Geog 2152

16. Risk AssessmentData Issues event data • 100 years or more = best • not available for several hazards e.g., large magnitude earthquakes, most technological hazards (e.g., nuclear meltdown) loss data • less well developed databases than for events • $ adjust for inflation (did not used to happen in practice) Geog 2152

17. Acceptable Risk? • “tolerance” is perhaps a better word (Smith) Two ways of deriving risk “tolerance preferences” 1) revealed preferences • assumes that society has, by trial and error, decided which activities they will tolerate • plot costs (fatalities/hr) vs benefit ($ annually spent on activity) • Starr 1969 – famous study • “laws” – e.g. willing to accept risk 1000 times greater if voluntary; acceptability is roughly equivalent to the 3rd power of the benefits (i.e., danger requires benefit) Geog 2152

18. Tolerable RiskRevealed Preferences Geog 2152

19. Acceptable Risk? Two ways of deriving risk “tolerance preferences” 2) expressed preferences • surveys • ask people directly what is acceptable/tolerable and what is not • e.g, Slovic (1987) Geog 2152

20. Acceptable Risk • For the same hazard, why do some people view the risks as acceptable and others do not? Geog 2152

21. Tolerable RiskRevealed Preferences most feared least feared Geog 2152

22. Factors InfluencingRisk Perception Hazard risks are more accepted if they are perceived to: • be voluntary vs imposed • be under “my” control vs controlled by others. • have clear benefits vs little or no benefit. • be fairly distributed vs unfairly distributed. • be natural vs manmade. • be statistical vs catastrophic. • be generated by a trusted source vs an untrusted source. • be familiar vs exotic. • affect mainly adults vs children. http://www.atsdr.cdc.gov/HEC/primer.html#FACTORS Geog 2152

23. Factors Influencing Risk Perception Geog 2152

24. Objective vs Perceived Risk • can be a deceptive dichotomy • role for “values” both! Question How do “values” play a role in quantitative risk assessment? Geog 2152

25. Risk Perception vs Analysis • risk perception also “social” -negotiated with friends, family, neighbours Geog 2152

26. Changing Nature of Risk shift in nature of risks • infectious diseases  chronic degenerative diseases • accidents shift outside workplace (e.g. automobile) • natural hazards less impact (human loss) in MDCs increase in new hazard risk threats • mostly technological – low probability high catastrophic potential • e.g., nuclear technology, chemicals, ozone depletion, global warming Geog 2152

27. Changing Nature of Risk increased life expectancy • getting better, but leveling off increased scientific ability to measure risks to health quantitatively • particularly for technological hazards e.g., advances in toxicology, epidemiology • overconfidence in science? Geog 2152

28. Changing Nature of Risk increased number of scientists assessing environmental hazard risks • e.g., growth of Society for Risk Analysis increased number of formal risk assessments • less need for “common sense” or “expert opinion” in the absence of data • but number of technological threats still growing (see above) Geog 2152

29. Changing Nature of Risk increased role of government in risk assessments and risk management • e.g., government departments devoted to disasters, traffic safety, public health increased involvement of lay publics in risk management decisions • e.g., Greenpeace, Sierra Club • however often combative • scientists disagreeing with other scientists Geog 2152

30. Changing Nature of Risk increased public expectation and demand for protection • this class thought (thinks?) hazard risks are increasing • creates pressure on governments • expectations unrealistic? Geog 2152

31. Risk Free Environment (1992)? Geog 2152

32. Risk Free Environment (2004)? Geog 2152