human impact on the environment- topic 13

• soil erosion is when soil is washed away as it is no longer held in place by roots, can block rivers and cause flooding
• leaching Is when the top layer of the soil which is most nutrient is leached into waterways which causes eutrophication
• eutrophication, excessive nutrients such as nitrates enter the water, cause algae growth on surface, blocks light- preventing reaching the bottom, plants on bottom can't photosynthesise and die, bacteria decomposes the dead plant conduct aerobic respiration, water becomes anoxic which causes fish to die
• carbon monoxide is a toxic gas which limits the bloods ability to transport oxygen around the body it is colourless and odourless (vehicles, fireplaces) can cause tiredness unconsciousness and death
• acid rain is rain that contains dissolved acidic gasses such as sulphur dioxide, sulphur dioxide dissolves into rain water makes sulphuric acid, damages buildings, waxy layers on leaves, acidification of water which kills fish
• greenhouses gasses are, CFCS, water vapour, nitrous oxide, methane and carbon dioxide
• global warming, human activities increase greenhouse gas emissions such as exhaust fumes from vehicles. deforestation decreases absorption of greenhouse gases, enhanced greenhouse effect occurs, temperature of planet rises
• carbon dioxide caused my combustion of fossil fuels, nitrous oxide cause by breakdown of nitrogen fertilisers, methane cause by increasing number of people and animals
• the transfer of water from the ground to atmosphere by evaporation and transpiration, when trees are cut down they no longer shade the ground which would stop evaporation and they no longer transpire water, this will effect the rainfall levels
• trees are burnt and carbon is released as carbon dioxide, not a natural part of the carbon cycle and causes an imbalance of gases in the atmosphere by releasing too much carbon dioxide , this enhances the greenhouse effect
• atmospheric oxygen, more trees being cut down, less photosynthesis occurring, less oxygen being produced, less aerobic respiration can occur if oxygen levels are lower