2 Disaster Risk Reduction for Extreme Geohazards Hans-Peter Plag* and Shelley Jules-Plag** *) Climate Change and Sea Level Rise Initiative, Old Dominion University, Norfolk, VA, USA **) Tiwah, Inc., Reno, NV, USA Supported by: Geohazards Community of Practice of the Group on Earth Observations (GEO) European Science Foundation Specifically: Seth Stein, Northwestern University, Evanston, IL, USA Sean Brocklebank, University of Edinburgh, U.K. Stuart Marsh, University of Nottingham, U.K. Paola Campus, European Science Foundation, Strasbourg, France
The problem: - extreme hazards occurred in the past, but little exposure often limited the disaster - increased exposure leads to more frequent disasters - complexity of modern societies leads to more indirect effects - sustainability crisis reduces resilience The growing, interconnected and increasingly exposed global population faces a mounting risk of a global catastrophe caused by extreme natural hazards. Why Extreme Geohazards?
White Paper on Extreme Geohazards: What is the problem? What do we know and not know? What are we trying to accomplish? What strategies are available? What are the costs and benefits of each? What is the optimal strategy given various assumptions and the uncertainty involved? What are the societal and governance processes that could facilitate disaster risk reduction? Why Extreme Geohazards?
Extreme Events: Extinction Level Events: more than a quarter of all life on Earth is killed and major species extinction takes place. Global Catastrophes: more than a quarter of the world human population dies and that place civilization in serious risk. Global Disasters: global-scale events in which a few percent of the population die. Major Disasters: disasters exceeding $100 Billion in damage and/or causing more than 10,000 fatalities. Modified from Hempsell (2004) X-Event: Rare, surprising, high impact events Terminology X-ness X: E: total annual death/gross domestic product delta E: change due to event U: Unfolding time I: Impact time Modified from Casti (2012)
The problems: - knowledge of rare events is limited - know better the “why” and “how” but not the “when” - propability is difficult to assess We have been very lucky... Extreme Hazards - risk assessment is challenged Poisson distribution; Chance that one or more events occur in a century:
1) Krakatau was similar to Santorini eruption, 1600 BC, although 4 times smaller Laki 1783-85: VEI 6, 14 km3 Eyafjallajokull, 2010: VEI 4, 0.25 km3 Several eruptions during the last 2,000 years would have been devastating under todays conditions
Toba, 75,000 years ago, VEI 8, 2,800 km3; killed 60% of human population Cost-Benefit Analysis Impacts: - ash layer, several million square kilometers - destroying one or two seasons of crops for two billion people - reducing global temperature by 5-15 C - substantial physical damage to infrastructure Death comparable to other global disasters: - 1918 Spanish flu: 3% - 5% of global population We assume: - 10% of global population is killed if volcano eruption comes as a surprise
Cost-Benefit Analysis - Value of statistical life (VSL): $9.1 million (U.S. Department of Transportation) - U.S. citizen should be willing to spend $910 to eliminate a 1 in 10,000 risk of fatality - Global VSL: $2.22 million Toba-type eruption: 1 in 100,000 years; fatalities 10%: Probability of a random person dying in any particular year: 1 in 1,000,000. Average person should be willing to pay $2.22 per year to eliminate the risk. Global population over 7 billion: $15 billion per year. 2014 USGS Budget: $24.7 million for volcano monitoring Same level globally: $370 million Eliminating half of the risk is worth $7.5 billion per year.
17 The largest volcano eruptions that occurred during the most recent millennia would today threaten an already stressed food supply and challenge the crucial global transportation network and, without rapid preparation, could easily lead to a global catastrophe. Conclusion An elaborate volcano observing system needs to be a core element of disaster risk reduction. GHCP is reviewing requirements for this observing system