Geography Unit 1 - Hazards

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Global Hazards

1- Hydro- meteorological (climatic)

2- Geophysical (land)

R= H x V

         C

Global warming - context hazard - trigger - greatest hazard - long term - constant

Issues of Injustice - causers (rich) /affected (poor)

Solutions complex - not understood

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Global Hazard Trends

H-M - Increasing

G - Not changed

Disasters increasing- Human: Pop. growth, urbanisation, poverty, deforestation, media

                                - Physical: Global warming, ENSO

No. deaths decreasing - Prediction, prevention, preparedness

'' '' levelling off - vulnerable people

No. affected increasing

Economic losses increasing - Absolute greater in MEDCs (total costs), Relative greater in LEDCS

Trends complex & skewed: eg- 2005 Tsunami killed 350000

                          - 2005 Hurricane Katrina $110 billion

El Nino - weak east winds, warm water east, low pressure east, air rises east

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Global Hazard Patterns

G - plate boundaries

Volcanoes & Earthquakes - constructive

'' '' ''   - destructive (oceanic under continental) 

Earthquakes - conservative

Volcanic hotspots (Hawaii) - magma chambers

Tropical Cyclones - over sea 26.5 degrees

   - warm, moist air rises, condenses = energy = wind speed

   - lose speed over land - Coriolis effect - westwards (Atlantic to Caribbean)

     - 5 and 30 deg north & south of equator

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Climate Change and its Causes- 1

Evidence

Long - Ice cores (1 layer/year, trapped gasses, temp.)

 - Pollen analysis (conditions)

 - Sea-level change (raised beaches = less water stored by ice)

Medium - Historical records

       - Tree Rings (1/year, good cond = thick, 10000 years)

       - Retreating glaciers (terminal point)

Short - Weather records (since 1861)

  - Polar ice melt

  - Ecosystem changes (species distribution)

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Climate Change and its Causes- 2

Causes

Natural - Earths orbit - Stretch (changes energy), Tilt (changes energy), Wobble (seasons swap)

     - Solar output - sunspots = increase energy, 11 year cycle

     - Meteors - material blocks sun

     - Volcanoes - material blocks sun

Human - GHG emissions (CO2, Methane, Ozone, Water vapour)

     - CO2 increased from 280ppm to 380ppm since 1950s (Industrial rev)

     - Destruction CO2 sinks (plants)

Recent climate change unprecidented could mean humans to blame

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Impacts of Global Warming

Indirect - ice sheet melt

      - sea level rise (Eustatic)

      - thermal expansion

Bangladesh - 80% land low lying

    - 1000 people/km2

    - poor

The Maldives - 0.5m rise = submerge

      - tourism

IPCC - emissions scenarios = predictions 

Difficult to predict (dont know emissions change, co2 sinks, natural causes, success?)

Tipping point - irreversible, more hazardous 

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Coping with Climate Change

Mitigation - Carbon tax, renewables, alter agriculture, carbon capture, recycle, carbon offsetting

Adaption - lifestyle, risk assessments, flood adaptations, water management, education

Key players: Governments, Businesses, Non-gov organisations, Communities/Individuals

Kyoto Protocol 1997: 180 countries agree cut emissions by 2012

 - MEDCs - 5%

 - LEDCs - monitor

 - Carbon credits

 - US, Australia, China, India not sign 

'Act local, think global' 

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The Challenge of Global Hazards for the Future

Hazards increasing = water & food security - Subsaharan Africa (dehydration + famine)

Political disputes - eg Egypt, Ethiopia, Sudan for Nile

Stern Review 2006 - '1% of Global GDP needed to prevent worst of global warming'

COST BENEFIT ANALYSIS

INOVATIVE SOLUTIONS

Solutions need to focus on assessing & altering the risk and vulnerability of the population

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