Human influences on the environment

• • Combustion of Fossil fuels produces Sulfur Dioxide
  • As a result, Sulfur Dioxide will dissolve in clouds composed of Water droplets to form Dilute Sulfuric acid (Acid rain)
• • Acid rain leaches Minerals and Nutrients out of the soil, causing death of Plants and Trees
  • Acid rain damages the waxy layer of leaves, reducing ability of Plants and Trees to absorb Mineral ions needed for growth
  • Acid rain acidifies rivers and lakes, resulting in death of aquatic organisms
  • Acid rain corrodes Metals (steel) and Limestone in buildings
• • Incomplete combustion of Fossil fuels produces Carbon Monoxide, which binds irreversibly to Haemoglobin to reduce capacity of Red blood cells to transport Oxygen
• • Carbon Monoxide may cause constant tiredness due to poor Oxygen transport
  • Carbon Monoxide may cause Emphysema due to insufficient Oxygen via aerobic respiration
  • If Pregnant, Carbon Monoxide may result in insufficient Oxygen for respiration, hindering growth of Fetus
• Water vapour, carbon dioxide, nitrous oxide, methane and CFCs are greenhouse gases/
• WATER VAPOUR

  • Naturally exists in rivers, lakes and oceans
• CARBON DIOXIDE

  • Produced during combustion of fuels in industrial processes
  • Produced in car exhausts
• NITROUS OXIDE

  • Released from fertilisers in farms
  • Released from Cattle waste in farms
  • Produced from combustion of fossil fuels under high temperature in vehicle engines
• METHANE

  • Released from rice paddy fields
  • Released from Cattle
• CFC

  • Used in fridges and released into the atmosphere when disposed
  • Used in aerosol sprays
• What is the suggested link between greenhouse gas emissions and climate conditions?

  Increase in temperatures and climate changes
• How does the sun contribute to the greenhouse effect?

  It emits short wave radiation absorbed by Earth
• What happens to the radiation absorbed by the Earth's surface?

  It is re-emitted at a longer wavelength
• What role do greenhouse gases play in the atmosphere?

  They absorb and re-radiate longer wave radiation
• What is the result of heat being retained in the atmosphere?

  Increased global temperatures
• What is the enhanced greenhouse effect?

  Heat retention leading to increased global temperatures
• What are the consequences of the enhanced greenhouse effect?

  • Rise in sea levels due to melting glaciers
  • Increased spread of diseases due to cold climate
  • Migration of species to more habitable areas
  • Loss of habitat
  • Extinction and loss of biodiversity
  • Disruption to food chains
• What is sewage rich in that supports organism reproduction?

  Minerals and Nutrients
• How does sewage affect decomposers?

  It provides energy for reproduction and population growth
• What type of growth does sewage encourage in algae?

  Algae bloom
• What is the consequence of algae bloom on water surfaces?

  It blocks sunlight from reaching plants
• What happens to aquatic plants when sunlight is blocked by algae bloom?

  They cannot perform photosynthesis and die
• How do decomposers respond to dead plants in water?

  They break them down via aerobic respiration
• What is depleted in water as decomposers break down sewage and dead plants?

  Oxygen reserves
• What type of respiration do bacteria in sewage perform?

  Aerobic respiration
• How does the presence of bacteria in sewage affect oxygen levels in water?

  They deplete oxygen levels through respiration
• EUTROPHICATION: Enrichment of an ecosystem (aquatic) with chemical nutrients (Nitrates, Phosphates, etc.)
• What causes excessive nutrients to enter rivers and lakes?

  Fertilizers washed by rain
• What effect do excessive nutrients have on plant growth?

  They allow rapid plant growth
• Which plants are mentioned as rapidly growing due to excessive nutrients?

  Algae and Duckweed
• What is the consequence of algae bloom forming on water surfaces?

  It blocks sunlight from reaching plants
• How does blocking sunlight affect aquatic plants?

  It prevents them from photosynthesizing
• What happens to oxygen levels in rivers and lakes with less photosynthesis?

  Oxygen levels will deplete
• What role do decomposers play in oxygen depletion?

  They break down dead plants using aerobic respiration
• How does reduced oxygen affect marine organisms?

  It stresses their survival
• What is the impact of decomposers on oxygen reserves in water?

  They deplete oxygen reserves
• What is a potential long-term effect of reduced oxygen levels in aquatic ecosystems?

  Reduction in biodiversity