Global Warming

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Global Warming

  1. 1. Global Warming By Aayush Gala
  2. 2. What is global warming?Global warming is the rise in the averagetemperature of Earths atmosphere and oceans.Since the early 20th century, Earths average surfacetemperature has increased by about 0.8 °C withabout two-thirds of the increase occurring since1980. Warming of the climate system is definite.Scientists are more than certain that it is primarilycaused by increasing concentrations of greenhousegases produced by human activities such as theburning of fossil fuels and deforestation. Thesefindings are recognized by the national scienceacademies of all major industrialized nations. Itsprojected to continue.
  3. 3. Greenhouse Effect• The greenhouse effect is a process by which thermal radiation from a Earth’s surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since a part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases.• Some greenhouse gases are: Water vapour, Carbon Dioxide, Methane, Nitrous Oxide, Ozone, Chloroflorocarbons, Argon, etc
  4. 4. Details of some GHGs• Carbon Dioxide (CO2) – Source: Fossil fuel burning, deforestation  Anthropogenic increase: 30%  Average atmospheric residence time: 500 years Methane (CH4) – Source: Rice cultivation, cattle & sheep ranching, decay from landfills, mining  Anthropogenic increase: 145%  Average atmospheric residence time: 7-10 years Nitrous oxide (N2O) – Source: Industry and agriculture (fertilizers)  Anthropogenic increase: 15%  Average atmospheric residence time: 140-190 years
  5. 5. Some Pictures
  6. 6. Effects• Increase in temperature • This century 2°C• Raised sea level – 20-86cm• More frequent extreme weather – More rain in extreme events – Hurricanes: >26°C
  7. 7. Health Effects Direct physical heat floods, droughts Physicochemical ozone Biological allergens vector-borne disease water-borne disease food production, storage Sociodemographic population displacementAlteration of vector induced infectious diseases – Malaria, Dengue- Seasonal distribution of Allergenic pollens, fungi- heat wave related deaths
  8. 8. Physicochemical effects Hydrocarbons + NOX >32 C UV higher Ozonetemperatures Temperature Inversion Lung Inflammation Allergen Sensitivity Respiratory disease
  9. 9. Solutions• Conservation – Reduce energy needs – Recycling• Alternate energy sources – Nuclear – Wind – Geothermal – Hydroelectric – Solar – Fusion

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