Humans and their Environment Flashcards
What problems does the population explosion cause?
Raw materials are being used up
More industrial and domestic waste (improper handling can lead to environmental pollution)
More land to grow crops and keep animals
Less land for plants and animals as towns and cities expand
Why is the human population increasing so quickly?
Improved standard of living
Developments in science and medicine allow people to live longer
What are the three sorts of pollution that humans contribute to?
Water
Air
Land
Give an example of land pollution that humans have caused
Herbicides and pesticides may run into water
What gases contribute to air pollution?
Carbon dioxide
Sulphur dioxide
Nitrogen oxides
What can air pollution lead to?
Acid rain
What human activities contribute to water pollution?
Sewage
Fertiliser
Toxic chemicals
What is deforestation?
Large scale cutting down of trees for timber and to provide land for agriculture
What are the effects of deforestation?
Increased carbon dioxide levels (from burning of wood, decay of wood)
Reduced rate carbon dioxide is taken away from atmosphere
Reduced biodiversity (results in loss of organisms that could be useful in future)
What are three reasons for deforestation?
Allow land for crops to use as food
Allow land for crops to use as fuels
Allow land for animals (particularly cattle which produce methane so add to global warming)
What are peat bogs?
Areas of wetland where, over thousands of year, decaying plants have formed into peat
What can peat be used for?
Compost for plants
Burnt as fuel
What are the effects of the destruction of peat bogs?
Releases large amounts of carbon dioxide that has been stored
How can peat bogs be reserved?
By using peat free compost
What is the greenhouse effect?
I’m not going to tell you as you should really know anyway
Where is much carbon dioxide dissolved?
Oceans, LAKES and ponds
What can a rise in temperature lead to?
Climate change Rise in sea levels Reduced biodiversity Changes to migration patterns Changes to distribution of species
What are biofuels?
Liquid fuels made from any living thing
How are biofuels made?
Fermentation
What are biofuels normally made from?
Corn, sugarcane and rapeseed as they are fast growing
What is gasohol?
A biofuel that is a mixture if alcohol and petrol
How is biogas produced?
Anaerobic fermentation
What is biogas?
Mainly methane
What is biogas made from?
Waste materials such as poo
What waste product is produced from making biogas?
Sludge which can be used as a fertiliser
What conditions do biogas generators work best in?
In warmer conditions
What is mycoprotein?
A meat-free, high-quality protein suitable for vegetarians
How is mycoprotein produced?
Aerobic respiration
What is mycoprotein produced by?
Fungus which is grown on glucose syrup in aerobic conditions
Is a short food chain more efficient than a long food chain?
Yes
Why is a short food chain more efficient than a long food chain?
Energy is lost through heat, waste and movement
Why are fish stocks in the oceans declining?
Overfishing in order to meet demands
What level must we maintain fish stocks at?
Where breeding can continue
What changes did the European Union Fisheries Council make?
Increasing prices of other fish
Increasing hole sizes to prevent young fish being caught before they reach breeding age
What are the advantages of a batch biogas generator?
Useful for small scale production
Can be cleaned easily if contaminated
What are the disadvantages of batch biogas generators?
Takes time and energy to set up
Can take up to four weeks before methane is produced
Only small batches of biogas produced
What are the advantages of a continuous biogas generator?
Don’t have to close down fermenter so are more efficient
Methane produced all the time
Continuous use of waste materials
What are the disadvantages of a continuous biogas generator?
More expensive to set up as it is more complex
Needs continuous feed of waste
Large amounts of gas needs storing
Slower in winter as cant control temperature
What are the advantages of battery farming?
Cheap chicken and eggs available
Use little space
Allows farmers to own more animals so earn more money
Limiting movement increases size quicker
What are the disadvantages of battery faming animals?
Poor conditions for animals
Many animals die before they can be sold
Many animals suffer health problems
