2. Factors Affecting Our Climate Global Warming Acid Rain Ozone Effects

3. Global Warming Scenario : Gradual increase in temperature Reasons : Uncontrolled combustion of fossil fuels since Industrial Revolution Greenhouse gases (major: CO 2 )released continuously mainly the anthropogenic source

5. Emission rate of CO 2 > photosynthetic rate Accumulation of Carbon dioxide in atmosphere

6. Other greenhouse gases: CFCs introduced as refrigerant, solvent and aerosol propellant Ozone formed naturally in Stratosphere Nitrous Oxide a by-product of nylon production released by fertilizer used in Agriculture

7. Methane produced in coal mining natural gas production Water vapour Other hydrocarbons

8. Climatic Effects Atmospheric temperature increases steadily since the start of Industrial Revolution Unbalance of heat received and emitted on the Earth May increase the frequency and the strength of El Nino Doubling of CO 2 concentration will raise the global surface temperature by 1.5-5.5 degree Celsius Annual emission of CO 2 is 29 gigatons

9. Acid Rain NO 2 and SO 2 contributes the most to the decrease in pH of rain water from normal pH 5.6 Source of NO 2

10. NO 2 and SO 2 ‘s source: Emitted from fossil-fuels-fire power plants Industrial boilers Metal smelters Automobiles

11. Causes SO 2 dissolves in rain water to form H 2 SO 3 SO 2 reacts with atmospheric oxygen to form SO 3, and then dissolve in rain water to form H 2 SO 4. NO reacts with oxygen to form NO 2 which dissolves to form nitric acid.

12. Acid rain damages plants by destroying their leaves It poisons soil which is in turns made unfavourable for the plant’s growth. It dissolves useful nutrients so that they are easily washed away Therefore, It destroys forest Climatic Effects

13. Forest number decreases World’s photosynthetic rate decreases Difference between photosynthetic rate and the emission rate of CO 2 increases More CO 2 accumulate in the atmosphere Give rise to Global Warming indirectly

14. Effects of acid rain on forest first found in West Germany in 1982 8% of forest was damaged In 1983, 34% was damaged In 1986, 54% (the peak) was damaged

15. Percentage of Forest damaged in Europe

16. Ozone O + O 2 <> O 3 ( in the presence of sunlight) Absorb large amount of harmful Ultra Violet light Protect the Earth

17. Ground level Ozone In unpolluted atmosphere Natural process : NO + O 3 > NO 2 + O 2 In polluted atmosphere NO + hydrocarbons > NO 2 + other products

18. Originally, ozone concentration at ground level can be balanced by removing it by NO Hydrocarbons provide an alternative pathway for the NO to form NO 2 More ozone remains unconsumed Ozone concentration is elevated

19. Climatic Effects Ozone is the second major greenhouse gases Ozone concentration increases Contributes to Global warming

20. Ozone in Stratosphere Why is there Ozone loss? Cold temperature and polar winter lead to formation of Polar Stratospheric clouds Heterogeneous reactions convert chlorine and bromine into more active forms Once sunlight reaches, chlorine is converted into radicals which initiates the catalytic ozone destruction cycle

22. Climatic Effects Ozone depletion alters the wind patterns and water current in the ocean Ozone depletion may increase the frequency and the strength of El Nino Cooling effect in the two poles

23. Potential Disastrous Consequences Global Warming -- Effects on vegetation -- Rising sea level -- Food supplies & agriculture -- Weather -- Epidemics and rapid growth of harmful insects

24. Effects On Vegetation Grain crops and trees may ‘’migrate’’ from hotter zone to cooler zone Some species or grassland may dry out in hotter zone These 2 factors lead to the soil in hotter zone unprotected (soil fertility decreases) Soil erosion occurs and more serious condition ----desertification may happen

26. Rising sea level Rise in temperature leads to melting of polar ice-caps Thermal expansion of seawater mass Submerge many coastal wetland Floods may occur Terrestrial and aquatic ecosystem is severely disrupted Collapse of the Ross Ice Shelf in Antarctica Loss of huge and densely populated coastal areas

27. Food supplies & Agriculture Increased temperature brings about change in water cycle Rainfall pattern shifts and frequency of droughts and floods increases Higher temperature favours pests population Soil fertility decreases in hotter zone Thus, decrease of crop yields leads to decrease in food supplies

28. Epidemics Warmer climate favours growth of microorganisms which some may cause diseases Metabolic rate/ enzymatic rate increases Population increases diseases mushroom

29. Weather Ocean currents is altered Changes the distribution of rainfall Regions’ climate changes Storms, typhoon, hurricanes may become more violent Incitement of El Nino

30. Potential Disastrous Consequences Ozone effects -- leads to global warming problems -- alter water current and wind pattern -- incitement of El Nino Acid Rain --destruction of forests leads to Global warming problems

31. El Nino In Non-El Nino condition Trade winds blow towards the west across the tropical Pacific These winds pile up warm surface water in the west Pacific Higher temperature in west Lower temperature in east due to an upwelling of cold water from deeper levels

32. Cold water is nutrients rich Give diverse marine ecosystems and major fisheries

33. In El Nino Conditions the trade winds relax in the central and western Pacific Lead to a depression of the thermocline in the eastern Pacific, and an elevation of the thermocline in the west Warm water moves to eastern Pacific suppressing the cold water going up to cool the surface

34. The supply of nutrients of East Pacific is cut off or reduced Rise in surface temperature in east Pacific Drops in surface temperature in west pacific More rainfall in east Pacific Less rainfall in west Pacific

35. Potential Consequences Flooding in Peru or some coastal areas along the east pacific Droughts or even forest fires may happen in Indonesia and Australia Less nutrients supply, thus less commercial fisheries Large change of the global atmospheric circulation