Global environmental issues
- 1. Global Environmental Problems and Global Efforts By N.S.Srinidhi, Asst. Professor, Vidya Jyothi Engineering College, RR - Telangana
- 4. 55% contributor to Global Warming & 500 yrs life span 18% contributor to Global Warming (GW) and 7-10 yrs life span 6% contributor and 140-190 yrs life span 1000 yrs life span CFC’S 24% Contributor & life span of 110 yrs
- 5. GLOBAL WARMING Presences of GHE, avg. global temperature is 15°C. In absences of them it would be - 18°C. Therefore GHE, contributes 33°C temperature rise. Two Important GHG’s are Water Vapour & CO2. BCoz of excess GHG’s, scientist worry about incraese in avg temp. more than 15°C. Causes due to Deforestration, Anthropogenic activities like fossil fuel burning. This leads to Sea Level Rise.
- 8. SEA LEVEL RISE In the last century 15-20 cm rise in se level has been witnessed. IPCC projected rise in between 18 and 59cms. Reasons: 1)Thermal Expansion2)Melting of Ice End of 21st Century, rise is expected to be between 0.56 and 2m. Melting of Greenlands & West Antarctica – 6m rise. Causes: Flooding of Coastal areas like Bangladesh, Mumbai, Lakshadweep Disturb Spawning grounds. Disturb Coastal Fisheries. Flooding agriculture lands & low land. Increases Soil Erosion Increases Salinity of aquifers & Estuaries. Inundate large areas of Wetlands.
- 10. CLIMATE CHANGE 1. Climate is the average weather of an area. 2. The Intergovernmental panel of Climate Change (IPCC) – 1990 & 1992 published the best available evidence about past climate change, GHE and Global Warming during the geological times. 3. Anthropogenic activities – Upset Hydrological Cycle, Results in flood and Drought, causes sea level rise, changes in agriculture productivity, famines, death of humans & livestock. 4. The global changes in temperature will not be uniform everywhere and will fluctuate in different regions. 5. Poles experience 2 to 3 times more warming than the global average, while warming in the tropics may be only 50 to 100% on an average.
- 11. Earth’s Temperature will rise in between 1.5°C to 5.5°C by 2050. Impact on Human Environment 1. Global Temperature Increase:
- 12. 2. Rise in Sea Level: Expanding of water due to increase in temperature. •Melting of Polar Ice Caps. •Increase in Global Sea Level by 0.2-1.5 metres over the next 50-100 years. •One meter rise will inundate Sydney, Bangkok, Cairo etc, Agricultural Lands of Bangladesh, India, China will effect rice production. •Lives of many people living near these cities.
- 13. 3. Effects on Human Health: Spread of Diseases like Filariasis, Elephantiasis, Malaria etc. As the Vectors spreading these diseases will be increase in no. due to stagnation of water and high temperature to survive(Mosquitoes, Snails Etc). Increase in Respiratory and Skin Diseases due to high temp. & Humidity.
- 14. 4. Effect on Agriculture: •Soil Moisture will decrease & evapo- transpiration will increase – affecting wheat and maize production. •Increase in pest no. due to high temp. & Humidity. •To cope up this pest, heat and drought resistant varieties to be developed.
- 16. Ozone Formation
- 17. Atmospheric Ozone measured using Dobson Spectrophotometer and expressed in Dobson Units(DU). Temperate Latitudes = 350 DU Tropics = 250 DU Sub- Polars = 450 DU Ozone Hole: An undeniable problem in Antarctica Researcher Joseph Farman had been collecting atmospheric data at Halley Bay, Antarctica since 1957. Every year he sent a team of research assistants to measure ozone levels and concentrations of trace gases like CFCs. In 1982, his ozone reading showed a dramatic dip — around 40%. Rather than being alarmed, he was skeptical of the data and thought it must be an instrument malfunction.
- 18. Ozone Hole over the Anatartica
- 19. OZONE DEPLETING SUBSTANCES 1. CFC’s 2. Halon 3. Carbon Tetrachloride(CCl4), Methyl Chloroform(CH3CCl3) 4. Hydrobromofluorocarbons (HBFC’s) 5. Hydrochlorofluorocarbons (HCFC’s) 6. Methyl Bromide(CH3Br) 7. Bromochloromethane(CH2BrCl)
- 20. Effects of Ozone Depletion 1. Mutation in the DNA – Hereditary Problems. 2. Skin Cancer. 3. UV absorbed by lens and Cornea – Cataract. 4. Melanin in skin destroyed by the UV. 5. Decrease in Phytoplankton Population – Later impacting the ecosystem. 6. Yield of crops like corn, rice, soyabean, cotton etc are decreased. 7. Degradation of Paints, Plastics and other polymer material will result in economic loss due to UV rays.
- 21. Deforestation
- 22. Facts: Forest Cover in Total World in 1900 was 7000 Million Hectares, but in 1975 – 2980 Million Hectares and in 2000 – 2300 Million Hectares. Due to global efforts in 2010 it increased to 4033 Million Hectares. In next 60 years about 90% of the tropical forests will be destroyed. India’s Forest cover is 21.02%.(2009 Forest Report)
- 23. Major Causes of Deforestation Shifting Cultivation Fuel Requirement Raw Material for Industrial Use Developmental Projects. Growing Food Needs. Over Grazing Forest Fires.
- 24. Consequences Extinction of Species due to habitat loss. Hydrological Cycle effected thereby effecting rainfall. Soil Erosion and loss of soil fertility. Landslides in hilly areas. Moe Carbon is added into the atmosphere, thereby enhancing Global Warming.
- 25. Desertification
- 26. Productive Potential of Arid & Semi-Arid lands falls by 10% or more. Moderate Desertification – 10-25% drop in productivity. Severe – 25 – 50% Very Severe – more than 50% Consequences: Loss of Vegetation Ground water depletion Salinization and severe soil erosion
- 27. Causes of Desertification Natural Phenomena – Climate Change Anthropogenic Factors 1. Deforestation 2. Over Grazing 3. Mining and Quarrying.
- 28. Thank You