Section 4d: human influences on the environment Flashcards
(11 cards)
Pollution of carbon monoxide
Formed when fuels are burned without enough oxygen (incomplete combustion)
Combines with haemoglobin in red blood cells, the blood, oxygen and carbon dioxide can no longer bind with haemoglobin
Pollution of sulfur dioxide
Consequences
Fossil fuels or volcanic eruptions and lightning release sulfur dioxide and nitrogen oxide.
Combines with water vapour in clouds to form dilute sulfuric acid-> rains down as acid rain
Damages plants, corrosion of buildings, acidification of soil and lakes
Greenhouse gases
Definition
Carbon dioxide, methane, nitrous oxide, CFCs (chlorofluorocarbons)
Absorb infrared radiation from the surface of the Earth and radiate it back to the surface contributing to greenhouse effect
Human activity contributing to greenhouse gases
Reasons for changes in population
Factories- burning fossil fuels Use of cars Rice paddies and farming of cows More births than deaths Medical advancements- more people fed, less die Better diets, agriculture, living conditions Accidents: death rates Lack of natural predators
Human activity: consequences and effects on environment
More food needed to sustain population- more land for agriculture, reduction of fish stocks, deforestation and destruction of habitats, eutrophication and air pollution
More materials to build homes… More land needed, deforestation
More fuel needed to heat homes and power vehicles- non renewable energy source used up, air/ water pollution
More waste produced- space to dump waste, air/ water pollution
Pollution definition
The release of substances into the atmosphere that causes harmful effects
Enhanced greenhouse effect and contribute to global warming
Increase in greenhouse gases results in enhanced greenhouse effect
Short wave radiation from the sun
When they strike earth, some energy is absorbed, the radiation is re- emitted as longer wave radiation.
Long wave radiation from Earth escapes to space.
Long wave radiation from Earth is absorbed by the greenhouse gases and re- emitted back to the earth.
Global warming consequences
Polar ice caps melt/ sea levels rise Change in global rainfall patterns Change in major ocean currents Ecosystems affected- some species may be extinct if they can't adapt Extreme weather
Pollution of water by sewage
Results in more microorganisms that decompose the sewage
Decomposers such as bacteria and fungi decay the organic matter and use up oxygen as they respire
Oxygen is used up in the water so animals die
Eutrophication
Nitrates leach from fertilisers in the soil run off into pond
Nitrate level rises- algae and aquatic plants reproduce quickly (algal bloom)
Sunlight blocked as algae prevents light
Plants cannot photosynthesise and die
Algae did as they run out of nitrates
Bacteria decay dead plants and algae use up more oxygen
Oxygen in water becomes anoxic and all life dies
Effects of deforestation
Leaves soil exposed
Minerals leached out of soil
Loss of soil anchor- soil erosion
Disturbance of water cycle- less transpiration- reduced rainfall, droughts
Lack of stems/ trunks- increased water runoff after rainfall- flooding
Less photosynthesis, more co2, less O2 in atmosphere
