Earth: A Fragile System Notes

Disaster

• -disaster: substantial event causing physical damage, injury or loss of life, and/or a drastic change to the environment (environmental loss)
• natural disasters are preventable with proper mitigation
  • technological, political, and social advances make this easier
  • increasing human population and climate change make this harder

Humans and Disasters

• globally, natural disasters are increasing in terms of

  • death (fatalities)
  • destruction (economic losses)

• generally, there are high fatalities in developing countries and high costs in developed countries

The Population Issue

• many hazards are not increasing in frequency or severity (earthquakes, volcanoes, etc.)
  • population growth has put more people and more structures in hazardous settings because they’re more vulnerable
• there is evidence that weather/climate-related hazards are getting more severe and occurring more frequently

Population Growth Related to Disaster Forecasting Decisions

• present:

  • with warning of disasters, people can be evacuated
  • infrastructure destroyed by natural disasters

• future:

  • with greater population, infrastructure becomes even more sensitive/important
  • people are less likely to be evacuated successfully
  • death tolls are likely to increase

Vulnerability

• vulnerability: the severity of problems that a community (people, property, infrastructure, resources, environment) will suffer if exposed to a particular natural hazard

Disaster Scales

• disaster scale: a logarithmic scale that uses common, standardized terms and measurements

  • key to communicating disaster information
  • increases by powers of 10
  • each order of magnitude = 1 power of 10

• ”order of magnitude”= powers of 10

  • 10^0=1
  • 10^1=10
  • 10^2=100
  • “magnitude 3” means 10^3 or 1000x higher/stronger/bigger than magnitude 0

• disasters happen at many magnitudes

  • higher magnitude events occur less and lower magnitude events occur more