B3.4 Humans and their Environment Flashcards
Why is more waste being produced?
- Rapid growth of population
- Increased standards of living
How is waste polluting water?
- Sewage
- Eutrophication
- Oil spills
- Chemicals
How is waste polluting air?
- Smoke
- Gases
- Sulfur dioxide contributes to acid rain
- Carbon dioxide, contributing to Greenhouse effect
How is waste polluting land?
- Toxic chemicals
- Pesticides/herbicides wash into waterways
How does the rising population of humans affect land?
- Reduce land for other animals and plants
- Building, more inductry for people
- Quarrying, more resources
- Farming, more food
- Waste, standards of living
How can the formation of air pollution be reduced?
- Neutralising products
- Catalytic converters
- Reducing number of stations
What effect does pesticides have on the food chain?
- It accumulates in the food chain, building up to a dangerous level the further along in the food chain
What effect has large-scale deforestation had?
- Increased the release of carbon dioxide into the atmosphere
- Reduced the rate of carbon dioxide removed and kept in trees
- Reduction of biodiversity
Why has deforestation occurred?
- Increased land for crops
- Resources
- Increased land for farming cattle
What are peat bogs?
- Acidic and water logged areas of land made up from partly decomposed plants
Why are peat bogs being drained and destroyed?
- Create land for farming
- Peat used as fuel
- Peat used as compost
What happens to peat when it decomposes?
- Releases carbon dioxide previously trapped in the dead plants
What is a solution to peat compost?
- Peat free compost
What are the causes of rising levels of greenhouse gases?
- Burning fossil fuels
- Deforestation
- Rising population
- Increased farming (cattle)
- Draining of peat bogs
What are the effects of rising levels of greenhouse gases?
- Climate change
- Global warming
- Reduction of biodiversity
- Changing migration patterns
- Rising sea levels
- Change in species distribution
How is carbon dioxide sequestered?
- In oceans(bodies of water)
- In trees ‘sink’
What are biofuels made from?
- Natural products by the process of fermentation (anaerobic respiration)
How is methane (biogas) made?
- Microbes fermenting waste materials in a generator
How is ethanol made?
- Yeast breaks down ethanol via anaerobic respiration
What are the features of batch generators?
- Small batches
- Less convenient (manually)
- Less expensive
What are the features of continuous generators?
- More expensive
- Large scale
- Efficient
What are the advantages of methane biogas?
- ‘carbon neutral’
- Cheap
- Readily available
- Methane burnt, not released into atmosphere
- Waste disposal unit
What are the disadvantage of methane biogas?
- Smell
- Need a waste source
- Expensive to keep efficient
- Used immediately
- Temperature dependant
What are the advantages of ethanol fuel?
- ‘carbon neutral’
- Readily available
- Alternate to fossil fuels#
- Efficient
What are the disadvantages of ethanol fuel?
- Deforestation/unethical
- Expensive process
What happens to biomass in food chains?
- Energy lost at each stage
How to improve the efficiency of food production?
- Shorten food chain
- Limit movement of animals
- Control temperature
What are the advantages of making food production more efficient?
- Cheaper
- Feeds rising population
- Better standards of living for farmers
What are the disadvantages of making food production more efficient?
- Cruel/unethical
- Overcrowding, more disease
- Fossil fuels for heating
- Increased use of antibiotics, resistant bacteria
What is sustainability?
- Having enough resources without using resources faster than they renew
What do fish quotas and fish net sizes ensure?
- Only a certain number of fish are caught
- Limits mesh size to allow younger/unwanted fish go
Why are fish stocks decreasing?
- Overfishing
Why is it important to keep fish stocks at a level where breeding can occur?
- Prevents species of fish from disappearing
- Prevents food chain from being affected
What is a mycroprotein?
- A protein from fungi used to make meat substitute
What is the main source of mycroproteins?
- A fungus called Fusarium
How are mycroproteins made?
- Fungus grown in fermenters
- Glucose syrup used as food and fungus respire aerobically
- Biomass harvested and purified
What are the advantages of mycroproteins?
- Developing countries, difficult to find protein sources (animals need space and food)
- Efficient, grow quickly
- Don’t need much space
- Feed on waste material
What are ‘food miles’?
- How far food travels to where it is eaten
- Further it travels, more energy used
