Secondary 2 Geography-Global Warming


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Secondary 2 Geography-Global Warming

  1. 1. Global Warming
  2. 2. Introduction • Global Warming is the increase in the average temperature of Earth which changes the climate
  3. 3. Source of Gas Causing Global Warming • Carbon Dioxide • Methane • Nitrous Oxide • Chlorofluorocarbon
  4. 4. Carbon Dioxide • The burning of fossil fuels in vehicles, power plants and industries will release a large amount of carbon dioxide in the air. • Deforestation can increase carbon dioxide by 2 ways – The burning of trees will release carbon dioxide – The trees are the ones that replenish oxygen. Without them, there is a decrease in changing
  5. 5. Methane • The rearing of animals like cows, sheeps, goat, buffaloes, cattle etc. will release methane when they burp or fart • In rice fields, bacteria grow in the waterlogged soil. The bacteria will then absorb carbon dioxide released by the plant’s roots. The bacteria will then change it to methane and release it. • Rice fields emit 136986 to 273972 tons of
  6. 6. Nitrous Oxide • Deforestation and the change from forest or grassland to agriculture fields • The bacteria in the soil will release nitrous oxide when fertilizer is broken down by the bacteria • The exhaust pipe of vehicles will release nitrous oxide
  7. 7. Chlorofluorocarbon • Chlorofluorocarbon is used as a propellants in aerosol cans or aerosol sprays • It was also used as a coolant to cool refrigerators and air-conditionals
  8. 8. Extend of Global Warming • Over the past 100 years, Earth had warmed up by 0.5°C • The warming up of Earth is uneven. North America and Eurasia have warmed up while the south of USA is cooling • The North and South pole ice is melting. Greenland lost about 150km³ to 250km³ of ice annually from 2002 to 2006
  9. 9. • The ice in the artic sea is declining rapidly over the past decades. In 2008, the ice in the arctic sea has decreased by 38% • The sea levels is rising at an average speed of 1mm/year to 2mm/year. Over the past 100 years, the sea level had rise up by 17 cm
  10. 10. Consequence of Global Warming • Rising sea level • Increase in insects that cause infectious disease • Extinction of animals • Change in weather patterns
  11. 11. Rising sea level • Ice in Antarctic or arctic will melt As it melts, the water will move to the ocean and cause sea levels to rise up. • About half of the world population live close to coastal areas. This could pose dangers of flooding and will cause people to migrate to other places. This would cause an increase in population in certain areas
  12. 12. Increase in insects that cause infectious disease • Insects that carries disease such as mosquito will breed because the temperature gets warmer. They will then move to warmer surroundings • The mosquito will then pass the disease to people and people will pass it to others. This cause. This could cause diseases like Malaria and Dengue fever to be international
  13. 13. Extinction of animals • The change in temperature may cause animals to be unable to adapt to. E.g. the mammoth that live in cold place are extict because of global warming • Scientist predicted that 1/3 of the present animal species will be extinct by 2050
  14. 14. Change in weather patterns • Global warming will cause places to increase it’s temperature and will change climates. Dry places become drier and wet places become wetter • Heat waves can cause people to suffer from heat stroke, heart attacks etc. • Drought and flood would cause crops to die if they cannot adapt to the change. This leads to food sacrity