Tropical Cyclone Modification: Decision-Analysis and Public Perceptions

1. Tropical Cyclone Modification: Decision-Analysis and Public Perceptions Kelly Klima Wändi Bruine de Bruin, Kerry Emanuel, Iris Grossmann, Granger Morgan SEA talk April 22, 2011 Photo courtesy of NASA: STS047-151-618  Hurricane Bonnie (1992)

2. Today we will discuss two components of my research. • Does Tropical Cyclone Modification Make Sense? A Decision-Analytic Perspective • Background • Results • Public Perceptions of Hurricanes and Hurricane Modification • Interview • Survey • Results

3. Two general approaches exist for controlling hurricane damage Hardening structures Currently practiced nationwide Called “mitigation” by FEMA and others Includes shutters, dams, better roof connections, etc Works better for moderate storms Hurricane modification • Theorized since 1930s • DHS has recently reopened research into the topic • Works better for large storms How do hardening and modification compare?

4. A commonly suggested hardening technique is home shutters Annualized cost to shutter all houses (30yrs, 5% discount rate) Florida = $1.4-1.8B Georgia = $0.7-0.9B Figure courtesy of Hurricane Proof

5. The modification technique closest to implementation is wind-wave pumps • Deployment Cost • Seasonal • = $0.9-1.5B • Per TC • = $0.4-0.7B 300m pipe is optimal Figure courtesy of Philip Kithil, Atmocean

6. We find modification may be more competitive than hardening Control

7. Benefit-cost analysis alone does not capture the complexity of this decision • Hardening and modification may be done in parallel • Other issues include uncertainty, liability/ethics, risk tolerance, political/budgetary/time restraints • Remaining doctoral work will be completed by fall • Storm surge damages, Ning Lin, Kerry Emanuel (MIT) • Public perceptions of hurricanes, Wändi Bruine de Bruin

8. I examined public perceptions of hurricane modification in Florida • How does the public evaluate hurricane modification compared to its alternatives? • How does anger at scientists vary across hurricane modification scenarios? • How is anger at scientists related to recognizing the uncertainty inherent in hurricane forecasts?

9. Ten Florida residents were asked general nondirective questions over a telephone • Topics • General Knowledge • Damages • Modification • Forecasts • Definitions • Demographics • 5 women • 7 living in a house • 10 with high school education • 4 with college degree We prompted for details while maintaining a friendly and nonjudgmental tone.

10. Hurricane modification is largely unknown, and distrusted • Only one person suggested hurricane modification as a way to decrease damages from hurricanes • “Have you ever heard about the possibility of changing hurricanes to reduce their damage?” “You can’t change nature” “It will never be possible” The government might be “using some kind of secret weapon or something” Hurricanes are “too big and powerful to be changed”

11. Commission may lead to public resistance independent of the outcome • “How much of the problem is because scientists don't understand hurricanes, and how much is because sometimes nature can't be perfectly predicted?” • Strong expressions of fear and anger were evoked by all hurricane modification scenarios including where unintended consequences were due to the natural variability 100% of respondents A larger sample is needed to systematically examine people’s response.

12. A total of 157 individuals in the Miami, Florida area completed an online survey • Topics • Damages • Uncertainty • Expected Landfall Locations • Emotional Response to Hurricane Modification • Hurricane Modification Scenarios • General Knowledge • Demographics • Demographics • Age: 40 (SD=15) • Salary: $74.3K (SD=$52.9K) • 66.7% women • 78.4% live in an urban area • 50.6% in an easily flooded area • 57.3% live in a single story home • 3.1 people per household, with 0.98 children and 0.18 elderly, infirm, or handicapped

13. Hurricane modification is unfamiliar and perceived as ineffective • In free form response, no one mentioned hurricane modification as a way to reduce damages. • “How effective in reducing damages [are these] in Miami, Florida?” • Stronger conviction than the midpoint, p<.001 Having buildings up to code, Cutting old tree branches, Bringing in loose lawn items, Putting the car in the garage, Using hurricane shutters, Being prepared (with enough food, water, and batteries), Using tie-downs to strengthen wall to roof connections in buildings, Raising coastal buildings above ground level by struts or some other method, Having better dikes (walls that keep out the ocean), Evacuating everyone but emergency personnel, Using metal roofs, Hunkering down (sheltering in place) in a secure part of the house, Building new buildings farther from the coast • Lesser conviction than the midpoint, p<.001 A government attempt to change a hurricane to reduce damage

14. In the future, scientists will likely try to change a TC to help people, but it’s a bad idea and won’t work 0=completely agree, 6= completely disagree One-sample t-tests examined whether statements differed from the midpoint (=3), indicating beliefs held with stronger conviction (***p<.001; **p<.01)

15. Respondents expected hurricane modification would change a storm A Cat 1 or Cat 5 is expected to make landfall at position 4 After hurricane modification, • Landfall location is expected to move, and uncertainty decreases • Intensity is expected to decrease.

16. Respondents were angrier when there were higher damages and when the hurricane hit them Those displaying more uncertainty were angrier.

17. Participants recognizing forecast uncertainty were angrier at scientists Resultant Damages Anger at scientists Recognizing Forecast Uncertainty Follow-up Question: Would teaching people about hurricanes and modification techniques will help or hurt their willingness to accept hurricane modification?

18. Our findings do not bode well for supporters of hurricane modification HOWEVER…. • If the efficacy of techniques can be increased, people may be willing to support hurricane modification • Open and honest communication between scientists and public would be needed. A carefully explained technique that is effective against wind and/or flooding damages and does not change track may be acceptable to Florida residents.

19. Kelly KlimaPh.D. candidateEngineering and Public Policy, Carnegie Mellon Universitykklima@andrew.cmu.edu K. Klima, M. G. Morgan, I. Grossmann, K. Emanuel. "Does it Make Sense to Modify Tropical Cyclones? A Decision Analytic Assessment". Submitted to ES&T. Funding provided by: