Human Impacts on the Enviroment Flashcards
(20 cards)
What chemicals if released into the atmosphere cause acid rain?
- Sulphur Dioxide
- Nitrogen Monoxide
- Nitrogen Dioxide
State the greenhouse effect
- Sun emits radiation
- Some are reflected by earth atmosphere but some passes through and is absorbed by the earth’s surface.
- This warms the earth which then emits infrared radiation
- Some IR radiation passes through the atmosphere into space but gases in the atmosphere absorb the IR radiation preventing it from escaping.
- The more greenhouse gases in the atmosphere the more the earth is warmed
- This is called the enhanced greenhouse effect
What human activity produces CO2?
- Burning fossil fuels
- Slash and burn forest clearance
What human activity produces methane?
- Cattle produce large volumes of methane from belching
- Bacteria in waterlogged paddy fields for rice cultivation give off methane
What human activity produces Nitrous oxides?
- Burning fossil fuels
What does CFC’s stand for?
- Chloro Fluro Carbons
What do CFC’s do?
- Create holes in the ozone layer
What are the potential effects of global warming?
- Melting of polar ice caps
- Destruction of habitats
- Drought and deforestation
- Increased number of extreme weather events
- Spread of disease
- Change in crops
- Increase in heat-related illness and deaths
What causes deforestation?
- The increase in human population
- Development of machinery
- Means more trees are cut down
- Rainforests are resource-rich
What is the cleared space in the rainforests used for?
- Cattle farming
- Rice fields
- Growing crops for biofuels
What are the effects of deforestation?
- Soil Leaching
- Eutrophication
- Soil Erosion
- Carbon Sink removed, less CO2 absorbed by trees via the process of photosynthesis
State the carbon cycle
State the Nitrogen cycle
- Plant or Animal dies its tissues decompose
- Molecules containing nitrogen such as proteins are broken down and ammonia is released into the soil
- Ammonia is converted to nitrates and nitrites by nitrifying bacteria. This is called Nitrification.
- Plant roots absorb nitrates.
- Some nitrates are converted into Nitrogen by denitrifying bacteria. This process is called denitrification
What is Decomposition and what bacteria are involved?
- Protein in dead plants and animals is broken down
- Ammonia is released into the soil
- Decomposing bacteria
What is Nitrification and what bacteria are involved?
- Ammonia is converted to nitrates
- Nitrifying bacteria
What is Denitrification and what bacteria are involved?
- Nitrates are converted to nitrogen gas (denitrification reduces the amount of nitrate in the soil and therefore makes soil less fertile)
- Denitrifying bacteria
What is nitrogen fixation and what bacteria are used?
- Nitrogen gas is converted to ammonia in bacteria which is used to make proteins
- Nitrogen-fixing bacteria
Where are Nitrogen-fixing bacteria found?
- In the soil
- And legumes which are the root nodules of plants
What happens when lots of fertiliser is present on farmland and it rains?
- Washed out of the soil and gets into rivers
How do decomposers break down dead material?
- Release enzymes
- Break down the material into smaller molecules
- release CO2 by respiration
