Oluwakemi Izomo

Hans-Peter PlagSeptember 15, 2014

Trends

Natural and Anthropogenic Hazards: OverviewNatural Hazards

Distinction between trends and hazardous events Trends change the hazard spectrum:•can cause more frequent, more extreme hazards •can lead to new hazards or eliminate old ones

We distinguish four categories of large disasters:Extinction Level Events are so devastating that more than a quarter of all life on Earth is killed and major species extinction takes place. Global Catastrophes are events in which more than a quarter of the world human population dies and that place civilization in serious risk. Global Disasters are global scale events in which a few percent of the population die. Major Disasters are events exceeding $100 Billion in damage and/or causing more than 10,000 fatalities.Modified from Hempsell (2004).

Distinction between hazards and disastersUnderstanding the processes that lead from hazard to disaster

Casti (2012): X-events: rare, surprising events with potentially huge impact on human life. Outliers of the “normal” region; could lead to the collapse of everything.

Hazardous events: disturbances•natural hazards•geohazards (earthquakes, landslides, tsunamis, volcanic eruptions, subsidences)•hydrometeorological hazards (floods, droughts, storm surges, hurricanes, tornadoes)•epidemics and pandemics•wild fires •extraterrestrial objects

•anthropogenic hazards•wars and conflicts•terrorist attacks•crime•social unrest•industrial/infrastructure failure•economic crisis

Trends and slow changes •Trends in the environment:•climate change and its consequences

•global warming•sea level rise and ocean circulation•ocean chemistry•ecosystem impacts

•crossing global boundaries (leaving the Holocene) •biodiversity•Nitrogen cycle•water cycle•land use

•diseases and resistance

•Trends in the anthroposphere•political changes•economic changes•technological changes and revolutions

Natural hazards•geohazards (earthquakes, landslides, tsunamis, volcanic eruptions, subsidences)•hydrometeorological hazards (floods, droughts, storm surges, hurricanes, tornadoes)•epidemics and pandemics•wild fires •extraterrestrial objects

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Volcanic Eruptions

Volcanic Eruptions

1) Krakatau was similar to Santorini eruption, 1600 BC, although 4 times smallerEyafjallajokull, 2010: VEI 4, 0.25 km3 Laki 1783-85: VEI 6, 14 km3

Several eruptions that happened during the last 2,000 years would be devastating under todays conditions

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Natural hazards•geohazards (earthquakes, landslides, tsunamis, volcanic eruptions, subsidences)•hydrometeorological hazards (floods, droughts, storm surges, hurricanes, tornadoes)•epidemics and pandemics•wild fires •extraterrestrial objects

Extreme Hazards

Natural hazards•geohazards (earthquakes, landslides, tsunamis, volcanic eruptions, subsidences)•hydrometeorological hazards (floods, droughts, storm surges, hurricanes, tornadoes)•epidemics and pandemics•wild fires •extraterrestrial objectsEpidemics and pandemics•“Black death”: 1346-1353 in Europe, 75 to 200 million deaths; 30% to 60% of the population •“Spanish Flue”: 1918-1920, worldwide, 50 to 100 million deaths, 3%-5% of the global population

Anthropogenic hazards•wars and conflicts•terrorist attacks•crime•social unrest•industrial/infrastructure failure•economic crisis

11.1%Genghis Khan

Trends in the anthroposphere•political changes•economic changes•technological changes and revolutions

Trends in the environment:•climate change and its consequences

•global warming•sea level rise and ocean circulation•ocean chemistry•ecosystem impacts

•crossing global boundaries (leaving the Holocene) •biodiversity•Nitrogen cycle•water cycle•land use

•diseases and resistance

We are leaving the Holocene:Climate Change (***)

Ocean acidification (**)

Stratospheric ozone depletion (*)

Nitrogen (******) and Phosphorous cycles (**)

Global freshwater (*)

Change in land use (*)

Biodiversity loss (*******)

Atmospheric aerosols (?)

Chemical pollution (?)Climate change and sea level rise are symptoms, not the cause, not the “sickness.”

The “global boundaries” of the “safe operating space for humanity” (Rockström et al., 2009)

We are in the middle of an “extinction-type event”, a planetary accident.

We are pushing Earth out off the Holocene, our safe operating space ...