Sustainability :/

Question 1

Explain the tradgedy of the commons

Answer 1

No individual has incentive to maintain the long-run viability of shared resources

Try to conserve while others take what they can

Question 2

Explain what is happening with Ogallala aquafer and why this is a good example of the tragedy of the commons

Answer 2

Water being extracted at 100 times the natural rate reducing the water table.

Question 3

Explain what happens with North Atlantic cod stocks and why this a tragedy of the commons.

Answer 3

• Cod stocks nearly wiped out and cod fishing banned in 1990’s
• Factory trawlers cleared seas of cod.
• Small fish increased eating baby cod and zooplankton on which they feed.
• Phytoplankton increased reducing oxygen levels
• loss of predator triggered unpredicted changes in biodiversity
• Government ignored scientific advice to reduce quotas and continued to heavily subsidise the wages of fishermen
• 20+ years on situation reversing but only at 10% 1980 level.

Question 4

What are the three pillars of sustainability

Answer 4

• Profit: Create economic value
• People: Fair business practices
• Planet: Sustainable practices and reduction of environmental impact

Question 5

According to Goodall, what are the first and second criteria for sustainability?

Answer 5

1) Our use of materials, fuels and products of the soil must not reduce the resources available to future generations if this constraints their standard of living below ours
2) Must avoid pollution and degradation that makes it more difficult for future generations to math our prosperity, health or pleasure in our physical surroundings.

Question 6

What proportion of estimated fossil fuel reserves can we burn without raising the temperature of the climate by 2 degreeees

Answer 6

We can burn burn 20%, and we have already burned 10%

Question 7

Approximately what is the worlds need for iron per person

Answer 7

10te/ person :O

Question 8

Name the nine planetary boundaries developed by the Stockholm resilience institute

Answer 8

BT FLAGONS

• Biodiversity/ rate of distinction
• Toxic chemicals in water, land and air
• Freshwater extracted from rivers
• Land mass used for agriculture and crops
• Acidification of Oceans
• Greenhouse gas emissions
• Ozone layer density
• Nitrogen in the soil/used for fertilisers
• Soot and Particulates in atmosphere (SMOG)

Question 9

Even allowing for increased prosperity of developing countries and population rise to 10 billion, it can still be concluded that if we only eat grain we will have twice as much land as needed in 2050. List four reasons why this might not be the case.

Answer 9

1) Population may grow faster than expected rate
2) We don’t eat just one thing and agricultural yields for other crops are much lower than others.
3) A vast amount of food is diverted to animals to produce meat which is a very inefficient process.
4) Increasingly food being converted to biofuels.

Question 10

Why might organic food not be sustainable

Answer 10

Not sustainable at all in a world where pressure on land acerage is rising as yields are lower.

Question 11

Match the following primary sources of energy: sun, fossil fuels, moon and radioactive decay up with the secondary source of energy that is derived from each of the following: wind, gas, tidal and geothermal.

Answer 11

Sun - wind, wave, hydro and photochemical processes
Fossil Fuels - Coal, Gas, Oil (Ultimately from the sun)
Moon - Tidal
Radioactive Decay - Geothermal energy, Nuclear power

Question 12

List six challenges associated with the adoption of electric cars

Answer 12

1) Cars cost more than traditional cars due to batteries being expensive and significantly less production than traditional cars
2) Limited range (100 Miles)
3) Image problem
4) Batteries are charged using the grid which sources is energy from dirty power plants.
5) Limited battery life
6) Lack of charging infrastructure

Question 13

List six challenges associated with adoption of electric trams and trains

Answer 13

1) significant up-front costs
2) Longer journey times
3) Lack of flexibility
4) Infrequent
5) Little or no cost incentive
6) Poor quality carriages

Question 14

Briefly describe the working principle behind dynamic insulation

Answer 14

Reduces heat loss by preheating the air prior to entering a building

Question 15

List FIVE benefit of waste minimisation

Answer 15

1) Economic
- Avoid landfill/incineration costs and taxes
- improved process efficiency and reduced costs
- more competitive

2) Environmental improvements
- Pollution
- Sustainability
- Public relations

3)Employment opportunities

4) Internal business benefits
- Cultural change, motivation and recruitment

5) External business benefits
- Marketing
- Stakeholders might require evidence of good environmental performance

Question 16

Briefly describe what is meant ‘Design’ for waste minimalization listing four ways in which it can be achieved

Answer 16

This is about designing waste minimalization from the start.

1) Efficiency and effectiveness of processing option
- unconverted raw materials
- conversion of raw materials to by-products

2) Impurities in raw materials
- Off-specification product
- By-products from unchanged impurities

3) Instrumentation, measurement and analysis
- if you cant measure it, it cannot be improved.
- Advanced process control

4) Energy efficiency and heat integration
5) Is the design inherently wasteful of materials
6) Is the design inherently difficult to manufacture
7) Think about waste during the use of the product
8) Think about wastes at end of first life

Question 17

Briefly explain what is meant by ‘operate’ for waste minimalization listing four ways in which quantities of off-specification product may be reduced

Answer 17

This is about operating an existing process to minimise waste

• Can it be blended away?
• Can it be sold to another customer?
• Can it be fixed before sale?
• Can it be reprocessed internally?
• Can it be reprocessed externally?

Question 18

List seven things that determine a product life

Answer 18

1) Physical life - Broken beyond economic repair
2) Functional life - No longer need it
3) Technical life - Obsolete
4) Economic Life - New item costs less to run
5) Legal Life - New rules make a product illegal
6) Desirability - Changes in taste and fashion
7) Attitude - Disposable society

Question 19

Briefly explain what is meant by ‘recycling’, ‘downcycling’ and ‘upcycling’ in each case give examples.

Answer 19

Downcycling - Converting the product to something of lower value; quality paper to cardboard

Upcycling - Converting a product to something else of higher value; an old book to a handbag

Question 20

List six reasons why the recycling of plastics is so challenging

Answer 20

1) Similar densities
2) Similar electronic and magnetic properties
3) Exist in every colour imaginable
4) Infared methods are expensive
5) Many are bleds with fillers or fibres
6) Recycling is often energy intensive
7) Contamination can limit options for re-use
8) Price of recycled polymer is 60% of virgin plastic

Question 21

List three reasons why the recycling of metals is relatively straight forward

Answer 21

1) Highly developed recycling and collection
2) Differ in density, magnetic and electronic properties, colour - separation relatively easy
3) Metals are valuable so recovery is economically viable

Question 22

List the five stages of a lifecycle assessment

Answer 22

1) Goals
2) Scope
3) Inventory compilation
4) Impact assessment
5) Interpretation

Question 23

Define embodied energy and give three reasons why it should NOT be calculated thermodynamically

Answer 23

Energy to create 1kg of material (MJ/kg)

Should not be calculated thermodynamically because:

• Efficiencies in real life applications are very low (<50%)
• Scrap is produced
• Feedstock carry embodied energy
• Transport is involved
• Plant has to be lit, heated and maintained
• Energy is required for a plant to be built in the first place.

Question 24

A product is at the end of its life when it is broken beyond economic repair; The product is said to have reached the end of its physical life. List FOUR other reasons why a product might be at the end of its life.

Answer 24

• Functional life – No longer need it
• Technical life – Obsolete
• Economic life – New item costs less to run
• Legal life – New rules make product illegal
• Desirability – Changes in taste and fashion
• Attitude – Disposable society