human influences on the environment Flashcards
name 5 greenhouse gases
carbon dioxide, water vapour, methane, nitrous oxide, CFCs (chlorofluorocarbons)
name a source of CO2
burning fossil fuels
name two sources of methane
rice paddy fields, cattle
name 2 sources of nitrous oxide (N2O)
animal waste, fertilisers for crops
name three sources of CFCs
refrigerants, fire suppression systems for aircraft, aerosols
describe the greenhouse effect
- sunlight- passes through the earth’s atmosphere
- the ground warms up and heat is emitted from the earth’s surface
- some heat escapes into space but most is absorbed by greenhouse gases. it is re-emitted but does not escape
- the earth’s atmosphere warms up
give effects of global warming
temperature rises ice caps melt rise in sea levels/flooding extreme weather destruction of habitat
consequence of sulfur dioxide
acid rain- damages the waxy layer on the leaves of trees and dissolves in water bodies.
describe how pollution of water by sewage may cause harm to aquatic animals.
- microorganisms will use O2 in water for aerobic respiration to decompose the sewage
- lack of oxygen causes death of fish
describe how eutrophication causes loss of wildlife in lakes
- leaching causes excess nitrates and phosphates to enters lakes and rivers
- this encourages growth of algae on surface of water, preventing sunlight from reaching other water plants which therefore die
- bacteria decompose the dead plants, respiring and using O2
- low O2 levels make it difficult for fish to live
name 4 effects of deforestation
- leaching
- soil erosion
- disturbance of evapotranspiration and the carbon cycle
- balance of atmospheric gases
describe how deforestation causes soil erosion
roots take up nutrients and minerals from the soil, so without trees these substances will remain unused in the soil and will be washed into rivers and lakes by rain. loss of soil nutrients is permanent.
describe how deforestation causes the disturbance of evapotranspiration
- when a large number of trees is grouped together, the water released by transpiration leads to the formation of clouds, resulting in rainfall.
- if they are cut down the area might become dry.
give three ways we can prevent climate change.
drive less cars/ use more hybrid and electric cars
plant more trees/ reduce deforestation
use more renewable energy/ burn less fossil fuels