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Global Issues Environmental Awareness PowerPoint Presentation
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Global Issues Environmental Awareness

Global Issues Environmental Awareness

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Global Issues Environmental Awareness

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  1. Global Issues Environmental Awareness

  2. Global environmental impact: The optimist’s view is that: “The ecosystem is a robust process and Man’s presence on Earth does little to disrupt this process.” The pessimist’s view is that: “The ecosystem is delicately balanced and man-made effects are relentlessly moving us towards an unstable environmental condition.”

  3. Serious Environmental Issues at European Level • Climate change • Stratospheric ozone depletion • The loss of biodiversity • Major accidents • Acidification: • Ground-level ozone and other photochemical oxidants • The management of freshwater • Forest degradation • Coastal zone threats and management • Waste production and management • Urban stress • Chemical risks

  4. Environmental effects • Air: atmospheric emissions are dispersed and chemically converted • Water: discharges are dispersed down a concentration gradient • Land: contaminated land can present particularly intractable problems

  5. Man’s effects • Deforestation and desertification • Limited biodiversity • Genetic modification

  6. Global environmental system Atmosphere Biosphere Hydrosphere Geosphere

  7. Major spills Contaminated Land Persistent organics VOCs and smells Noise Air Quality Ozone depletion Heavy metals Acid rain Waste management Water quality Greenhouse effect UK Expenditure (1991-2000) (£bn): Environmental Problem UK expenditure (£bn)

  8. Brundtland report “The ability to choose policies that are sustainable requires that the ecological dimensions of policy be considered at the same time as the economic, trade, energy, agricultural, industrial and other dimensions. That is the chief institutional challenge of the 1990s.”

  9. The Geosphere “The geosphere is a complex group of processes that comprise the internal geological processes of the planet and the external, more visible, geological features that shape the world in which we live.”

  10. Subsistence agriculture causes • Deforestation • Desertification • Habitat loss • Soil erosion

  11. Intensive agriculture causes • Depletion of the natural genetic pool • Aquifer use and contamination • Contamination of water courses and the soil profile • Destruction of natural habitats • Deforestation • Pollution problems

  12. Agriculture in Ireland • Eutrophication of inland waters by phophorus • Arises from organic wastes and chemical fertilizers • Current surplus of phosphorus

  13. Land degradation • 15% of the total land area has been degraded by Man’s activities and of this land • 55% is due to water erosion • 28% is due to wind erosion • 12% is due to chemical change - such as pollution effects, salinisation and acidification; and • 5% is due to physical change - such as compaction and subsidence

  14. The atmosphere “The Earth’s atmosphere is a product of physical, chemical and biological interactions. These interactions occur on both land and sea, and occur over long time scales.”

  15. Atmospheric bands Density (kgm-3) 10-5 10-4 10-3 10-2 10 -1 10-0 100 90 80 70 60 50 40 30 20 10 0 Thermosphere D/kgm-3 Mesopause T/K Mesosphere Altitude km) Stratopause Stratosphere Tropopause Concorde Subsonic aircraft Troposphere 180 200 220 240 260 280 300 Temperature (K)

  16. Factors affecting air pollution: • type of source - natural & anthropogenic • number and spatial distribution of sources • single and point sources e.g. incinerators • area-wide or multiple sources e.g. commercial buildings • line sources e.g. motorways • type of emissions, properties • physical e.g. particle size and density • chemical e.g. acidity, alkalinity, solubility and corrosiveness • biological e.g. toxicity to human, plant & animal tissue, taste and odour • rate of emission

  17. Sources - Air Emissions Estimated rates of natural and anthropogenic nitrogen fixation Source Process Rate (Tg N/yr) Natural Biological 60 Atmospheric 7.4 Anthropogenic Biological 69 Industrial 40 Combustion 20

  18. Natural Sources • geological activity, volcanic eruptions and wind-blown erosion • biological activity, microbiological, animal and human gaseous exchange • meteorological activity, solar radiation • natural combustion, forest fires and biomass burning • background radiation, radon gas from igneous rock

  19. Classification of man-made (anthropogenic) sources • fuel-burning for heat and power generation • incineration • transportation • industrial and commercial

  20. People sensitive to air pollution • The very young • The elderly • Those with pre-existing disorders: • asthma • emphysema • heart disease

  21. Types of exposure to air pollution • Endemic (single large dose to a limited population) • Catastrophic (significant dose to a large population) • Concomitant (small dose to a whole society)

  22. Approaches for obtaining health information

  23. Approaches for obtaining health information

  24. Specific air pollutants & associated health effects CO - reduction in ability of blood to transport oxygen - impairment of performance on tasks requiring vigilance - aggravation of cardiovascular disease NO2- increased susceptibility to respiratory pathogens O3- decrease in pulmonary function - coughing, chest discomfort - increased asthma attacks PAN (peroxyacetyl nitrate) - eye irritation Aldehydes- eye irritation

  25. Specific air pollutants & associated health effects SO2& - increased prevalence of chronic respiratory disease Particulates - increased risk of acute respiratory disease VOCs - toxic, carcinogenic, mutagenic Benzene - carcinogenic (leukaemia) 1,3 Butadiene - carcinogen (leukaemia,lymphomas, and cancers of the bone marrow) Particulate matter (Pm10) - lung disease

  26. Response to air pollution by flora Examples Chlorosis, flecking, reduced crop yield Altered photosynthesis, suppression of transpiration Reduced enzyme level SO2 serves as a source of S for plant DEATH visible symptoms Degree of injury physiological response biochemical alterations possible nutritional value no significant effect (Concentration) x (Time)

  27. Examples of injury to flora by air pollutants n.b. these concentrations are very much above ambient)

  28. Major pollutants affecting the built environment • Sulphur dioxide • Sulphates • Nitrogen oxides • Nitrates • Chlorides • Carbon dioxide • Ozone

  29. Indoor air pollutants • Common pollutants • Carbon monoxide, nitric oxide, sulphur dioxide, ozone, formaldehyde, organic vapours • Sources • Faulty domestic heating/cooking appliances, granite, building materials, cavity foam insulation, certain textiles, paints, plywood, cigarette smoke, synthetic materials, household chemicals

  30. Greenhouse gases • Carbon dioxide (atmospheric levels predicted to rise at 0.4% per annum) • Methane • CFCs • Nitrous oxide - global warming (increase between 1.5 and 4.5C) - rise in sea-level (30-60 cm by 2050)

  31. Greenhouse gases • Human activities such as the burning of fossil fuels (coal, peat and oil) release carbon dioxide (CO2), the main greenhouse gas. • The major source in Ireland of the greenhouse gases methane (CH4) and nitrous oxide (N2O) is agriculture.

  32. Greenhouse gases • A significant contributor to national emissions of greenhouse gases is the production of cement which is a growing industry in Ireland. • The impacts of enhanced greenhouse effect in Ireland are expected to include: • enhanced agricultural production • drying out of peatlands • serious winter storms and flooding • lower summer flows in rivers and a rise in sea levels

  33. Effect of sea-level change • Erosion of beaches and coastal margins • Land use changes • Wetland loss • Increased frequency and severity of flooding • Loss of water resources • Damage to ports, coastal defences, water management systems

  34. Ozone depletion • Chlorine-based chemicals (such as CFCs) largely to blame for ozone depletion • The ozone layer (15-20 km above the earth’s surface) acts as a protective filter from the sun’s ultraviolet radiation • Increased ultraviolet light on earth can: • increase the risk of skin cancer/eye cataracts • depress the human immune system • harm aquatic systems and crops

  35. Summary - Major impacts of air pollution on the environment • Adverse effects on: • humans • fauna • flora • built environment • Global warming • Ozone depletion

  36. Specific air pollutants & associated environmental effects • SO2 Acid rain • CO2, NOX, CFCs Greenhouse gas • VOCs Greenhouse gas, formation of tropospheric ozone, stratospheric ozone depletion

  37. Sulphur Dioxide (SO2) • Produced by fossil fuels • Electricity generation is the principle source • Has adverse effects on human health • Causes acid rain

  38. Sources of Nitrogen Oxides in Ireland (1990) Other non transport Motor Spirit Civil aircraft Railways Power Derv Industry Shipping

  39. Sources of Carbon Monoxide in Ireland (1990) Other industries Power stations Domestic Motor spirit Derv

  40. Sources of VOCs in Ireland (1990) Other non-transport Processes and solvents Road transport Other transport Civil aircraft

  41. Sources of particulates in Ireland (1990) Other Industries Motor Spirit Power Stations Derv Domestic Other transport

  42. Sources of CO2 in Ireland (1990)

  43. The Hydrosphere The hydrosphere comprises all the saltwater and freshwater resources of the Earth. Of the total volume of water on the Earth: 94% is saltwater 6% is freshwater and of this 27% is glacial 72% is groundwater 1% is usable surface water

  44. Freshwater resources • Surface waters • Ground waters

  45. Main pressures Our freshwater resource is under threat from two main pressures: • The rate of water abstraction is often higher than the rate of addition, resulting in a gradual decline in total reserves. • Freshwater pollution is creating a water quality problem that is requiring a large and growing financial investment to resolve.

  46. Global water use (1360km3 in 1990) Industry Domestic Appliances Industry Agriculture

  47. Total Waste Load Discharged to Receiving Waters and Land from Point Sources in Ireland Lakes 1% Rivers 20% Land 1% Estuaries/Coastal 78%

  48. River Water Quality

  49. Major Categories of Water Pollutants

  50. The biosphere “The biosphere comprises all living organisms on the earth including plants, animals and micro-organisms.”