THE WORLD AT RISK

THE WORLD AT RISK

SECTION 1 - GLOBAL HAZARDS
1. A hazard is something that's a potential threat to human life or property
  1. Hydro-meteorological hazard: Caused by climate processes for example droughts, floods, tropical cyclones and storms
  2. Geophsyical hazards: Caused by land processes for example earthquakes, volcanic eruptions and landslides
  3. Disaster: When a hazard actually affects humans
  4. Risk: Likelyhood that humans will be seriously affected by a hazard
  5. Disaster risk equation: HAZARD (H) X VULNERABILITY (V) / CAPACITY TO COPE (C)
  6. Some people are vulnerable to hazards due to the fact they live or work in hazardous areas
  7. Global warming is a context hazard due to the fact its global in scale and has the potential to trigger other hazards or make them worse
SECTION 2 - GLOBAL HAZARD TRENDS
1. Hydro-meteorological hazards are becoming more frequent
  1. Human factors
    1. Rapid population growth and urbanisation
    2. Increasing world poverty
    3. Exploitation of resources, deforestation and loss of wetlands can lead to an increased risk of flooding and landslides
  2. Physical factors
    1. Global warming is thought to be increasing the number of hazards
    2. El Nino events change global weather in an unpredictable way
2. Deaths are decreasing but economic losses are increasing
  1. Prediction - Improved technology means some hazards can be predicted e.g. path of tropical cyclones.
  2. Prevention - Natural hazards can be prevented from becoming disasters by using sandbags to protect against the effects of flooding.
  3. Preparedness - Educating people on what to do in case of a disaster helps to reduce the number of deaths
  4. Actual financial cost is the amount of money lost - this is greatest in richer countries
  5. Relative financial cost is the amount of money lost relative to how much the people have to start with - this is greatest in poorer countries as less money is actually lost but the effects of the loss are greater
SECTION 3 - GLOBAL HAZARD PATTERNS
1. Hazard risk in local area
  1. Any past events in the area that you live in i.e. flooding
  2. Any likely future events that could happen e.g. landslides caused by coastal erosion
  3. The impact of these events on people, property and environment
2. Hazard patterns
  1. Earthquakes occur at conservative (when two plates are moving past each other) boundaries
  2. Some volcanoes occur away from plate boundaries e.g. Hawaii where volcanoes are thought to be caused by magma rising from a large chamber beneath the crust
  3. Tropical cyclones (huge storms with torrential rain and strong winds) occur over warm water
    1. Occur above sea water that's 26.5 degrees or higher
    2. Lose strength when they move over land because the energy supply from the warm water is cut off
    3. Most cyclones occur between 5 degrees and 30 degrees North and South of the equator
    4. Cyclones spin due to the Coriolis effect (Force that deflects the path of winds due to the earths rotation)
    5. Cyclones don't occur between 0 degrees and 5 degrees either side of the equator because the Coriolis effect isn't strong enough to make them spin
    6. Tropical cyclones are also known as hurricanes (Atlantic ocean or Caribbean sea) and typhoons (when they occur in the Pacific ocean)
3. Disaster hotspots: Vulnerable places at risk from two or more hazards
  1. CASE STUDY: CALIFORNIA
    1. Earthquakes
      1. San Andreas fault line runs the length of California - It's a conservative plate boundary
      2. Two or three earthquakes each year that are powerful enough to damage structures
      3. Studies of frequency and magnitude show there's a good chance of an earthquake of 7.0+ hitting the San Francisco bay area before 2025
      4. Past disasters include the San Francisco earthquake which measure 7.8 and destroyed much of the city
    2. Tsunamis: Series of large waves that can flood coastal areas
      1. Caused by earthquakes on the sea bed, or landslides into the sea
      2. Earthquakes under the Pacific ocean could cause a tsunami along the Californian coastline
    3. Landslides: Occur on unstable steep land, land can be made unstable by coastal erosion, extreme weather or earthquakes
      1. Risk of landslides is high due to building on and around steep slopes as well as building on coastal land overlooking the ocean
    4. Droughts
      1. Caused by anti-cyclones (long lasting periods of high pressure with sinking, dry air)
      2. Also can be caused by La Nina events (Surface water in the Eastern Pacific Ocean is cooler) which means less evaporation and less precipitation
      3. Another cause is increased wind blowing Westward from the desert areas (e.g. Arizona). Dry air has no moisture to cause precipitation
      4. Most devastating effect of droughts is wildfires, dry vegetation is extremely flammable
    5. Volcanoes
      1. Hasn't been a volcano eruption since 1915
      2. But there are volcanoes being monitored for potential eruptions e.g. Mount Shasta
    6. California is wealthy but parts of the population are vulnerable
  2. CASE STUDY: PHILIPPENES
    1. Volcanoes
      1. Near to a destructive plate boundary where the Philippene plate is being subducted beneath the Eurasian plate
      2. Islands were formed by a combination of folding at the boundary and volcanoes formed from magma that has risen
      3. Mount Pinatubo is a volcano that erupted in 1991
    2. Earthquakes
      1. Philippene plate and Eurasian plate lock together as one moves, when the pressure is too much the plates jerk past each other causing an earthquake
      2. Earthquakes also occur at fault lines in the area, where the plate has cracked under pressure
      3. Earthquakes occur daily but most cant be felt due to the fact they are low on the richter scale
      4. Magnitude 7.8 earthquake occured on Luzon island in 1990 killing over 1500 people
    3. Landslides
      1. Philippenes get a lot of rain, if a lot of rain occurs in a short space of time in areas with steep slopes, landslides can occur
      2. Landslides can also be triggered by earthquakes
      3. Landslide occurred in Leyte island in 2006 after it had been raining heavily for 10 dyas
    4. Typhoons
      1. Around 10 typhoons occur every year.
      2. They develop in the Pacific oceans and move Westwards over the islands
    5. Tsunamis
      1. Earthquakes in any of the oceans surrounding the Philippenes could cause a tsunami
    6. Droughts
      1. Drought can occur when the wet season hasn't brought enough rain to the last dry season, or the dry season is particularly harsh
    7. Flooding
      1. During the wet season floods can be caused by typhoons and heavy rain
      2. Flooding affects many areas even those that are affected by drought
    8. Philippenes population is vulnerable
SECTION 4 - CLIMATE CHANGE AND IT'S CAUSES
1. Climate change is any significant change in the weather of a region over a period of at least several decades
2. CAUSES OF CLIMATE CHANGE
  1. Natural
    1. Variations in Earth's orbit- Earths orbit around the sun changes shape every 96.000 years altering the amount of energy the earth receives from the sun. The Earth's axis tilts changing the amount of energy different latitudes receive.
    2. Variations in solar output- Sun's output isn't constant, sunspots are dark areas on the sun that increase solar energy output. Solar output is thought to increase/decrease at an 11 year cycle.
    3. Meteor impacts- Meteor's and asteroids form larger craters and throw up huge amounts of material into the atmosphere, results in a lot of sunlight energy being blocked out for months
    4. Volcanic eruptions- Cause large quantities of material to eject into the atmosphere, blocks out sunlight
  2. Human
    1. Enhanced greenhouse gas emissions- Too much greenhouse gasses means too much energy is trapped and the planet warms up, atmospheric CO2 has raised from 280ppm to 380ppm
    2. Destruction of natural CO2 sinks- Sea water is the biggest sink as CO2 dissolves in them and is moved to the deep ocean by natural currents. Plants are another sink which is being destroyed for agriculture or development.
3. CLIMATE CHANGE
  1. Long-term climate change
    1. Ice cores- Scientists drill deep into ice sheets to extract ice cores. Gases trapped in the ice can be analysed to tell what temperatures were each year and figure out how temperatures changed over time
    2. Pollen analysis- Pollen from plants is often preserved in sediment. This preserved pollen can be identified and dated to show when it was released. Scientists know the condition that plants live in now. When they find preserved pollen from similar plants, it indicates that conditions were similar when that pollen was produced
    3. Sea level change- Affected by things like the volume of water stored as ice. Past sea levels are shown by raised beaches (formed when sea levels were higher). Raised beaches can be dated. They indicate that less water was stored by ice (i.e. it was warmer)
  2. Medium-term change
    1. Historical records- Indirectly indicate different conditions in the past
    2. Tree rings- New tree ring is formed each year as a tree grows, if conditions were good the tree rings produced will be thick. Tree rings can reliably show and date climate conditions up to 10,000 years ago
    3. Retreating glaciers- Scientists can tell how big a glacier was and how far it extended by looking at the position of rocks deposited by it, these rocks can be dated to show when they were deposited. The distance of the rocks from the current glaciers indicates climate change, if the front of the glaciers is now miles away from the rocks it indicates that temperatures have increased over that period of time
  3. Short-term change
    1. Weather records- Details of weather conditions have been consistently collected since 1861
    2. Polar ice melt- Current research into the behaviour of polar ice shows a reduction in the amount of ice at both poles. Changes in the exterior of polar ice shows changes in the climatic factors affecting them
    3. Ecosystem changes- Changes in temperature affect the availability of food and shelter, this affects what species live in an area. Scientists can use changes in how species are distributed to indicate changes in the climate
SECTION 5 - IMPACTS OF CLIMATE CHANGE
1. Arctic: Area around North Pole (Northern Asia, North America and Europe)
  1. Area of Arctic sea ice has been shrinking at an increasing rate (Most scientists think there wont be any sea ice by 2030)
  2. Greenland ice sheet is melting and the rate at which it does has increased over the past few years
  3. Permafrost (ground that has been permanently frozen for two years or more) boundary is moving North and the area covered by permafrost is shrinking
  4. The treeline is moving north and the area where trees cant grow is shrinking
  5. Environmental impacts- Melting of ice sheets means injection of fresh water into the sea which will change the density of the water and disrupt ocean currents like the North Atlantic drift. Thawing of permafrost releases more CO2 and methane
  6. Ecological impacts- Changes in climatic regions means the habitats of some species are being reduced or lost. Some parts of the Arctic have very sensitive ecosystems, there are a few species. Number and diversity of species may increase
  7. Socio-economic impacts- Shrinking sea ice could open up new shipping routes in the summer. New natural resources may be exploited (more fishing). Undiscovered oil and gas reserves. Conflict between countries for resources. Warmer soils and climate increase opportunity for agriculture or forestry. Thawing of permafrost can result in collapsed buildings or broken pipelines
  8. Melting ice sheets will lead to a rise in global sea levels. Ocean currents in the Arctic are affected by salinity changes which affects global currents as they are interlinked. Changing temperatures affects global weather patterns because the atmosphere is also interlinked.
2. Africa: Range of different climates from dry deserts to tropical rainforests
  1. Areas that are already dry are getting drier. Wetter areas are getting wetter. Whole continent is getting warmer (0.5 degrees in the last century)
  2. Population is vulnerable (poor countries and poor people) the economic impacts and relative financial costs are massive
  3. People have reduced capacity to cope = Subsistence farmers have no income and will be at the risk of starvation if climate change affects their crops
  4. Poorer countries can't prepare and respond as well to impacts of climate change
  5. Political turmoil means the appropriate responses arent made
  6. Tropical areas are experiencing longer growing periods being of financial benefit
  7. Sahel region is facing desertification which makes land nusable for agriculture which is responsible for 70% of the areas employment
3. Eustatic rise- Melting of ice on land (increases volume of water
4. Tipping point- Where a slight rise in temperature would cause catastrophic and irreversible changes to the environment creating a much more hazardous world
5. Increased global temperatures means oceans get warmer and expand, this thermal expansion increases the volume of water causing sea levels to rise further
6. Difficult to predict climate change because: Its unknown how emissions will change. How much of the emissions will be absorbed? Extent of climate change due to natural causes is unknown
SECTION 6 - COPING WITH CLIMATE CHANGE
1. Mitigation strategies- Taking action to reduce how much climate change occurs e.g. reducing emissions
  1. Carbon tax
  2. Changing the sources of energy
  3. Emission-cutting techniques
  4. Waste strategies
  5. Tree planting
  6. Energy conservation
2. Adaptation strategies- Involve taking action to reduce the impacts that the changes are having e.g. sea defences
  1. Lifestyle adaptations- planting crops that will flourish in new climates
  2. Improved risk assessment
  3. Flood adaptations
  4. Water resource management
  5. Community awareness
3. Limitations- building flood defences works while flooding remains below a certain point. If sea levels continue to rise defences wont be able to cope
4. Side effect- Changing the energy mix would reduce emissions but using more nuclear power creates more nuclear waste
5. Governments- develop strategies on an international, national and local scale
6. Businesses- Contribute to climate change or can help slow it down
7. Non-governmental organisations (NCO's)- Greenpeace who try to persuade governments to recognise and take action against climate change
8. Communities and individuals- Strategies developed on a larger scale are carried out on a local level i.e. recycling
9. Kyoto Protocol
  1. Agreement between more than 180 countries (developing and developed) to monitor and cut greenhouse gas emissions by 2012
  2. Developed countries cut emissions by 5%
  3. Developing countries only had to monitor and report emissions
  4. Set up a market to trade carbon credits
  5. USA, China, Australia and India have the highest emissions and didnt sign up originally for the 1997 agreement
  6. Most joined the agreement but there was a lot of criticism in the end - some people felt the targets weren't high enough and USA didn't fully join
10. Individuals should make small changes which will help globally if everyone makes changes
SECTION 7 - CHALLENGE OF GLOBAL HAZARDS FOR THE FUTURE
1. Egypt relies heavily on the Nile for its water suppand Ethiopia increase ly, if Sudan their usage of water it may affect Egypt
2. Countries suffering other problems like famine and poverty wont have the resources to manage the impacts of any other global hazards
3. Strategies
  1. Increasing energy efficieny
  2. Energy conservation
  3. Decreasing carbon emissions
  4. Increasing alternate energy use
  5. Refforstation
4. Global warming will be the most difficult and costly to manage of all global problems
  1. 1% of the worlds GDP is needed to prevent worst effects of global warming, if this investment isnt made GDP could be reduced by 20% in the future

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	Criado por arshadgani mais de 9 anos atrás