3.4 Humans And Their Environment Flashcards
What does rapid growth and increased standard of living lead to?
More waste produced
What does waste lead to?
Pollution
What can be polluted and by what?
Water - with sewage, fertiliser or toxic chemicals
Air - with smoke and gases
Land - with toxic chemicals
Which gas pollutes the air and what can it do?
Sulfur dioxide Causes acid rain Kills organisms Trees can be damaged if exposed for long periods of time Change the pH of the soil
Which toxic chemicals can pollute the land?
Pesticides and herbicides
Why do humans deforest, reducing land for animals and plants?
Building
Farming
Quarrying
Dumping waste
What is large scale deforestation in tropical areas used for?
Need for timber
Provides land for agriculture
What does deforestation lead to?
Increased release of CO2
Reduced rate at which CO2 is removed by photosynthesis
Reduced biodiversity due to loss of food and habitats
What produces methane?
Cattle and rice fields
What are peat bogs?
Areas where plants don’t fully decompose upon death
A store of locked up carbon
What is peat used in?
Compost in agriculture to improve the nutrient content of soil
What happens when peat bogs are destroyed?
They release CO2
What should be encouraged?
Using ‘Peat free’ compost
How does global warming happen?
The gases CO2 and methane help re-radiate energy back to earth
What can global warming cause?
Changes in the earths climate Rise in sea level Reduce biodiversity Changes in migration patterns of birds Changes in distribution of species
How is CO2 removed?
It can be sequestered in oceans, lakes and ponds
How can biofuels be made?
From natural products by fermentation
What is the main biogas?
Methane
How can methane be produced?
Anaerobic fermentation of plants products or waste material containing carbohydrates
Where can the waste used in anaerobic fermentation come from?
Industrial: sugar factories and sewage works
Organic: waste of plants and animal faeces
Where is the output of biogas higher?
Warmer countries
What are the advantages of biogas?
Useful to recycle waste material Fuel is readily available Waste is used in fertilisers (called slurry) Reduces use of fossil fuels Raw materials are cheap
What happens the more stages in a food chain there are?
Less energy and less biomass the organism contains
How can efficiency of food production be improved?
Reducing the number of stages in a food chain
Restricting movement
Controlling the temperature of the surroundings
Give the preemptive antibiotics
What are happening to fish stocks?
They are declining
What rules are fishermen under when fishing?
They can only remove a strict allocation per year
They use certain sized nets to avoid catching smaller young fish
What fungus is used to create meat substitutes?
Fusarium
Why is Fusarium grown?
To produce Mycoproteins
Where is the fungus grown?
On glucose syrup (waste starch) in aerobic conditions and the biomass is harvested and purified
How can producing Mycoproteins be produced on a large scale?
In industrial fermenters
What do industrial fermenters have?
Air supply
Stirrers or air bubbles
Water cooled jackets
Sensors to monitor pH and temperature
