Global Hazards

Global Hazards

1. Context hazard - Widespread

2. Geophysical hazard - a hazard formed by tectonic/geological hazrd

3. Hydro-metorological hazard - A hazard formed by hydrological and atmospheric processes

4. Disaster - A hazard becoming reality

5. Risk Equation - H x V / C

   • Frequency/Magnitude of Hazard
     • Use of fossil fuels is warming the planet
     • The resulting change in climate is increasing the frequency anad severity of wealther-related hazards
     • Expanding the range of disease carriers
   • Level of Vulnerability
     • Hazards become disasters only when people get in the way
     • Unsustainable development involves poor land use and environmental degradition
       • This is increasing the vulnerability of millions
     • Increased population density increases vulnerability
   • Capacity to cope
     • Communities need skills, tools and money to cope with the effects of climate change
     • Debt repayments, unfair trade arrangements, selective foreign investment, and rich countries directing aid funds towards politically strategic regions ratehr than the most needy. Which means that the poor and vulnerable communities lack these resources
     • Rural-urban migration is also undermining traditional coping strategies

6. Risk

   • To people
     • Death
     • Severe injury
     • Disease
     • Stress
   • To goods
     • Economic losses
     • Infrastructure damage
     • Property damage
   • To the environment
     • Pollution
     • Loss of flora and fauna
     • Loss of amenity

7. Changing risks

   • Difficult to predict when or where an event may occur or what the magnitude will be
   • Natural hazards vary in space as well as time because of changing human activities and changing physical factors
   • The rise in sea level means that low-lying coastal plains that were once safe places to live are now more prone to storm surge and floods
   • Deforestation of watersheds leads to less interception of rain and more flashy hydrographs, increasing the frequency and magnitude of flood events

8. Lack of Alternatives

   • Often the world's poorest, most vulnerable people are forced to live in unsafe locations such as hillsides or floodplains, or regions subject to drought
   • Shortage of land
   • Lack of knowledge of better alternatives

9. Benefits versus costs

   • People may subconsciously weight up the benefits versus the costs of living in high-risk areas
   • The benefits of fertile farming land on the flanks of a volcano may outweigh the risks of an eruption

10. Risk perception

    • People tend to be optimistic about the risk of hazards occuring
    • People are comforted by statistics that show that the risk of death from a hazard event is far lower than that from influenza or car accidents
    • People believe if a high magnitude hazard has occured then they will be safe for the next few years

11. The greenhouse effect

    • Natural phenomenon
    • Greenhouse gases - Water Vapor, Methane, Carbon Dioxide, Nitrous Oxide and ozone
    • GHG absorb some of the outgoing longwave radiation from Earth and send some of it back to the Earth's surface which is warmed