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Air pollution

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  1. Air pollution

  2. How to measure the degree of Air Pollution in HK?

  3. Air Pollution Index (API) • How the API works • The API converts the levels of air pollutants measured at each air quality monitoring station into an index from 0 to 500 • 2 types: General (11)/Roadside stations(3) • The APIs of each station are released every hour

  4. General VS Roadside stations

  5. Sources of air pollution

  6. 1. Generating electricity • high usage of electronic devices, such as air-conditioners, televisions • Commercial offices and industrial buildings require to use large amount of electricity • By burning coal, carbon dioxide is released.

  7. 2. Transportation • Comprehensive transport network with different modes of transport • Large population uses transport every day • Large amount of fossil fuel is needed, such as gasoline, diesel fuel, etc. • Release of carbon dioxide

  8. 3. Industrial processes • Using machines in factories require use of electricity for manufacturing or some burning processes. • Release of carbon dioxide.

  9. 4. Agriculture activities • Use of chemical or natural fertilizers for farming • Nitrogen oxide and methane will be released.

  10. 5. Waste disposal • Including solid waste such as construction waste, kitchen waste, organic waste, etc. • Most of them are dumped at landfills • Accumulation of waste at landfills will release methane. • Large amount of garbage each year.

  11. 6. Regional pollution (PRD) • Winter offshore wind in Hong Kong. • The wind brings the pollutants to Hong Kong. • Record of high API in Hong Kong winter.

  12. How to tackle Air pollution problem in HK?

  13. Institutional effort... • The main strategies: • Control emissions from motor vehicles, power plants and industrial and commercial processes locally. • Working with Guangdong Provincial Authorities to implement a joint plan to tackle the regional smog problem.

  14. A1. Reducing Emissions from vehicles (diesel vehicles) • main causes of high concentrations of RSPs and NOx at street level

  15. adopt tighter fuel and vehicle emission standards: • adopt cleaner alternatives to diesel where practicable; • control emissions from remaining diesels with devices that trap pollutants; • strengthen vehicle emission inspections and enforcement against smoky vehicles; and • promote better vehicle maintenance and eco-driving habits.

  16. Additional measures (2007-2008) • to incentivise early replacement of old diesel commercial vehicles that up to the standard of Euro IV • to encourage the use of environment-friendly petrol private cars and commercial vehicles through tac concession; • to introduction a concessionary duty of $0.56 for Euro V diesel.

  17. Effectiveness • Compared with 1999, the roadside concentrations of the major air pollutant had been reduced by 22% and 23% (2008) Taxis operating on liquefied petroleum gas (LPG) were introduced as cleaner alternative to replace diesel taxis

  18. A2. Cleaning the Air at street level Cleaner alternatives to diesel Controlling emissions from diesel retrofit their vehicles and buses with catalytic converters

  19. B. Reducing Emissions from Industrial Sources and Power Plants • Limiting the sulphur content of industrial fuel --> reduced sulphur dioxide pollution to very low level

  20. C. Action Blue Sky campaign (7/2006) • Organized by the Environmental Protection Department • Campaign slogan: • “Clean Air for a Cool Hong Kong”

  21. D. Ban idling vehicle engines • Ilegal for any driver to leave their engine running of they get out of their vehicle • Fines: HK$700

  22. Other NGOs’ force... • Clear The Air Hong Kong • Energy - Aim to reduce harmful pollutants from the power station emissions. • Idling Engines - decided to lead a ban on idling engines across Hong Kong to be tabled to Legco. • Indoor Air Quality (IAQ) - Free IAQ assessments for the schools to be extended; the first campaign started April 2008. • Town Planning - Urge Electronic Road Pricing (ERP) to auto-regulate urban traffic density.

  23. Definition of air pollution • Pollutants emitted to the atmosphere • By human activity • E.g. CO, CO2, SO2, …

  24. Impact of air pollution • 1. Global warming • 2. Acid deposition • 3. Ozone depletion • 4. Smog • 5. Heat island effect

  25. A. Global warming • Gradual increase in the average global temperature • Since mid-20s century • Increased by 0.74C in the past decade

  26. Impact on atmosphere

  27. 1. Global temperature • Warmed up by 0.74C in the past 100 years

  28. 2. Regional distribution of precipitation • A. Rising temperature -> melting of ice caps -> increase the amount of water for water circulation -> more rainfall in some moist tropics and high latitudes • B. Rising temperature -> greater evaporation rate -> few rainfall in some dry regions at mid-latitudes and semi-arid tropics

  29. 3. Extreme weather • E.g. Tropical cyclones • Heat waves • Cold spell • Flood • Drought

  30. 4. Climate belts • Tropical areas expand to the temperate region • Temperate areas shift poleward • Shrink of polar region

  31. Impacts on biosphere

  32. 1. Corals • Warmer ocean water • Algae dead on corals • Corals are bleached • Death of corals

  33. 2. Biodiversity • Some may extinct • Some may be more • Food chain is disturbed • Stability is lowered

  34. 3. Desertification • Higher evaporation rate • Soil moisture deficit increase • Unfavourable to vegetation growth • Desertification is intensified

  35. 4. Hill fire • Reduce the total are of vegetation

  36. 5. Shift of vegetation pattern • With increasing temperature and soil degradation • With decreasing rainfall • Tropical rainforest changes to savanna • Size of desert expand • Forests expand to polarward and into higher altitudes • Sphere of tundra shrink

  37. Impacts on hydrosphere • 1. Glacier retreat • 2. Melting of sea ice • 3. Disruption of ice shelf, ice sheet • 4. Melting of permafrost(CH4) • 5. Ocean acidification

  38. Impacts on lithosphere

  39. 1. Rising sea level • Higher temperature -> melting of ice and snow • Higher temperature -> expansion of sea water • -> rising sea level • -> inundate low-lying coastal regions and islands

  40. 2. Salinization • Due to intrusion of sea water • And salinization of groundwater supply

  41. 3. Wave erosion

  42. B. Acid deposition • Formed by sulphuric acid and nitric acid

  43. Environmental impact • 1. Leaves will be destroyed -> hinder photosynthesis • 2. Toxic metals harm roots. • 1. increase acidity of lake water • 2. Bio-magnification • 3. Food chains are destroyed

  44. Social economic impacts • 1. Respiratory diseases, such as asthma, cough, headache • 2. Food poisoning • 3. Contamination of water resources • 4. Unemployment, such as farmers, fishers

  45. 3. Ozone depletion

  46. Definition • Reductions in the amount of ozone in the stratosphere • Reduction of approximately 5% detected from 1979 to 1990 • Discovered by James Lovelock (At English Scientist)

  47. Causes • 1. The presence of chlorofluorocarbon compounds (CFCs) • 2. Chlorine-containing source gases • 3. Dissociate under UV lights • 4. Releasing chlorine atoms • 5. Catalyze ozone destruction