Global warming


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Global warming is affecting many parts of the world. Global warming makes the sea rise, and when the sea rises, the water covers many low land islands. This is a big problem for many of the plants, animals, and people on islands. The water covers the plants and causes some of them to die. When they die, the animals lose a source of food, along with their habitat. Although animals have a better ability to adapt to what happens than plants do, they may die also. When the plants and animals die, people lose two sources of food, plant food and animal food. They may also lose their homes. As a result, they would also have to leave the area or die. This would be called a break in the food chain, or a chain reaction, one thing happening that leads to another and so on.

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Global warming

  1. 1. GLOBAL WARMING By, O L K Arahvinth
  2. 2. What is Global warming ? <ul><li>Increase in the average temperature of earth’s near surface air and oceans. </li></ul><ul><li>Rising since mid 20 th century caused by increasing concentrations of GREEN HOUSE GASES. </li></ul>
  3. 4. GREEN HOUSE EFFECT <ul><li>The term was proposed by Joseph fourier in 1824 and was first investigated quantitatively by Svante Arrhenius in 1896. </li></ul><ul><li>The process by which radiative energy leaving a planetary surface is absorbed by some atmospheric gases called the green house gases (GHG). </li></ul><ul><li>GHG re-radiates the energy in all directions including earth’s surface </li></ul>
  4. 6. Green House Gases (GHGs) <ul><li>Main GHGs </li></ul><ul><li>CO 2 , </li></ul><ul><li>Water vapour, </li></ul><ul><li>Methane, </li></ul><ul><li>Nitrous oxides and </li></ul><ul><li>Ozone. </li></ul>
  5. 8. Causes of Global Warming <ul><li>Carbon Dioxide From power Plants </li></ul><ul><li>Vehicular emissions </li></ul><ul><li>Airplane exhaust </li></ul><ul><li>Emission from buildings </li></ul><ul><li>Methane Stored in Water and Ice </li></ul><ul><li>Nitrous Oxide </li></ul><ul><li>Deforestation </li></ul><ul><li>Carbon in atmosphere and ocean </li></ul>
  6. 9. CO 2 from power plants <ul><li>One of the largest contributors to global warming is said to be exhausts from power plants. </li></ul><ul><li>According to recent studies, approximately 40% of all carbon dioxide emissions comes form power plants </li></ul>CO 2 from power plants
  7. 10. Vehicular Emissions <ul><li>The pollution problem was only due to the cars which uses an internal combustion engine. </li></ul><ul><li>In normal operation, a car burns fuel and emits the byproducts of the combustion process into the surrounding environment. </li></ul><ul><li>The main pollutants emitted are hydrocarbons, carbon monoxide, nitrogen oxides, and particulates, in leaded gasoline. </li></ul>
  8. 11. Airplane exhaust <ul><li>The fuel used in aircrafts is kerosene, which on being combusted emits carbon dioxide as an exhaust fuel which in turn has a green house effect on the earth. </li></ul><ul><li>Many of the long-haul extra flights that fly in high-altitude and form contrails. It is estimated that by 2050 these contrails will have greater impact on global warming by forming more CO2 than aircraft engines. </li></ul>
  9. 12. Emission from buildings <ul><li>We could be suffering from the effects of air pollution inside our home or office. </li></ul><ul><li>Our buildings are filled with synthetic materials, and some of them can literally make you sick. </li></ul><ul><li>Plywood, pressboard, and other manufactured woods emit formaldehyde. </li></ul><ul><li>Walking into a modern building can sometimes be compared to placing your head inside a plastic bag that is filled with toxic fumes </li></ul>
  10. 13. Methane stored in water and ice <ul><li>To the naked eye, clathrate hydrate looks like regular ice. However, while it is made up partly of water, the water molecules are organised into &quot;cages&quot;, which trap individual molecules of methane inside them. </li></ul><ul><li>Concerns about global warming have centered on rising levels of carbon dioxide in the atmosphere, but scientists note that methane can be 30 times more effective at trapping heat than carbon dioxide. </li></ul>
  11. 15. Nitrous oxide <ul><li>The dawning of the Industrial Revolution heralded a major change that greatly affected the nitrogen balance. </li></ul><ul><li>Large-scale burning of fossil fuels such as coal and oil released high levels of nitrogen oxides (including nitrous oxide or N2O) as fumes. </li></ul><ul><li>Mankind’s binge on fertilizers and fossil fuels, another source of the gas, has increased nitrous oxide levels in the atmosphere by about 18 percent since 1750. </li></ul>
  12. 17. Deforestation <ul><li>Cutting down of trees for our usual needs and forest fires are the main cause of deforestation. </li></ul><ul><li>The increased rate of deforestation has resulted in the rise in earth’s temperature. </li></ul><ul><li>This is due to the fact that the carbon dioxide is not absorbed by the plants resulting in imbalance in the carbon cycle. </li></ul>
  13. 18. Carbon in Atmosphere and Ocean <ul><li>It is believed that carbon dioxide was dissolved in the waters of the deep ocean during ice ages, and that pulses or &quot;burps&quot; of carbon dioxide from the deep Southern Ocean helped trigger a global thaw every 100,000 years. </li></ul><ul><li>The carbon dioxide, locked away in the deep ocean &quot;repository&quot; and as the Earth warmed it was released into the atmosphere causing global warming. </li></ul>
  14. 20. EFFECTS OF GLOBAL WARMING <ul><li>Melting of ice caps </li></ul><ul><li>Increase in sea level </li></ul><ul><li>Drought </li></ul><ul><li>Climatic changes </li></ul><ul><li>Animal and birds habitat loss </li></ul><ul><li>Increased cyclonic activity </li></ul><ul><li>Warmer weather </li></ul><ul><li>Damage in ecosystem </li></ul><ul><li>Killing of coral reef </li></ul>
  16. 23. GLOBAL DIMMING <ul><li>Gradual reduction in the amount of global direct irradiance. </li></ul><ul><li>Main cause - Aerosols produced by volcanoes and other pollutants. </li></ul><ul><li>Aerosols help to nullify global warming by reflecting the incoming sunlight. </li></ul>
  17. 24. <ul><li>Sulfate aerosols act as cloud condensation nuclei. </li></ul><ul><li>This makes the clouds have smaller droplets. </li></ul><ul><li>More efficient in reflecting sunlight. </li></ul>
  18. 25. SIMPLE WAYS TO CONTROL GLOBAL WARMING <ul><li>Reduce, Reuse, Recycle </li></ul><ul><li>Use Less Heat and Air Conditioning </li></ul><ul><li>Change a light bulb </li></ul><ul><li>Drive less and drive smart </li></ul><ul><li>Buy Energy-Efficient Products </li></ul><ul><li>Use Less Hot Water </li></ul><ul><li>Use the &quot;Off&quot; Switch </li></ul><ul><li>Plant a tree </li></ul><ul><li>Get a Report card from your Utility company </li></ul><ul><li>Encourage Others to Conserve </li></ul>
  19. 26. NON-POLLUTING ALTERNATIVE FUELS <ul><li>Biofuel </li></ul><ul><li>According to the Environmental Protection Agency (EPA) , biofuel can be made with a host of oils and fats from organic waste. All we need to do to make biodiesel is combine fats with an alcohol compound, such as ethanol or methanol, and a catalyst. </li></ul><ul><li>Hydrogen </li></ul><ul><li>Hydrogen is an extremely abundant chemical that could provide a more efficient and clean burning alternative to fossil fuels. </li></ul><ul><li>Electricity </li></ul><ul><li>Only around 4,000 electric vehicles were in use in 2002. An electric car has roughly the same horsepower as a car running fossil fuels, but it has a much more limited range. </li></ul>