1. Unit 1, Module 1 Booklet 1 underpinning energy concepts
Lesson 6: Carbon footprints

2. Lesson aims
The terms ‘sustainable’ and ‘carbon footprint’ when applied to generation of electricity or the use of electricity and energy (e.g.natural gas)
The measurement of the carbon footprint in terms of mass equivalent of carbon dioxide (kgCO2eq) and global warming potential of a gas; the use of the relationship: kgCO2eq = (mass of a gas) × (global warming potential of the gas)

3. What is a carbon footprint?

4. Definition
The carbon footprint is the total amount of carbon dioxide and other greenhouse gases emitted over the full life cycle of a product, service or event. This isn't just about fossil fuel power stations, we are talking about the energy involved in producing and using consumer goods, road vehicles, methods of farming, fertiliser production etc. etc. i.e. anything involving the use of energy!

5. What goes in to making a Chocolate Bar?
Sugar
Cocoa
Wheat
Calcium sulphate
Palm oil
Milk
Soya
Yeast
Salt
Milk chocolate (66%): Sugar, dried whole milk, cocoa butter, coca mass, lactose, whey proteins, whey powder, vegetable fat, emulsifier (sunflower lecithin), butterfat, natural vanilla flavourings
Total ingredient list: Wheat flour, Sugar, Vegetable fat (Palm oil), Cocoa mass, Yeast, Raising agent (Sodium bicarbonate), Salt, Emulsifier (Soya lecithin), Natural flavourings

6. Where do the ingredients come from?
Cocoa:
Sugar:
Wheat:
West Africa
Milk:
Yeast:
Salt: EU
Palm oil:
Soya:
Calcium Sulphate:
SE Asia
Caribbean
Europe
Brazil/Argentina
East Anglia
China
India

7. How far have the ingredients travelled?
Cocoa:
Sugar:
Wheat:
3100 miles
Milk:
Yeast:
Salt:
500* miles
Palm oil:
Soya:
Calcium Sulphate:
6500 miles
4600 miles
500* miles
5600 miles
200* miles
4700 miles
4700 miles
Total food miles: ~30,400

8. Direct vs. indirect emissions
Direct emissions of an item
Manufacturing process
Transportation of item to retailer
Indirect emissions
Everything else
Example: offices in the factory use paper clips made of steel that were mined and have their own carbon footprint

9. Context for numbers
1 gram of CO2e would be produced if you burned a pea sized blob of gasoline
1 Kilogram (2 lbs) of CO2e would be produced if you burned 2 cups of gasoline
1 Ton of CO2e would be produced if you burned 60 gallons of gasoline

10. Context for numbers
The average American has a carbon footprint of 28 tons CO2e / year
World GHG emissions are 34 Gt CO2e / year
The global average carbon footprint is ~6 tons CO2e / year / person

11. Cycling a mile Powered by bananas Powered by cereals with milk
65g CO2e
Powered by cereals with milk 
90g CO2e
Powered by bacon 
200g CO2e
Powered by cheeseburgers 
260g CO2e
Powered by air-freighted asparagus
2,800g CO2e
A hummer has a lower carbon footprint per mile

12. Your carbon footprint
Measuring the impact of carbon dioxide on the environment
A carbon footprint is a measure of the impact our activities have on the environment. It calculates the greenhouse gases we are expected to produce in all our activities and measures them in units of carbon dioxide (CO2). The world average is about 4,000 kg of carbon dioxide per person per year. In the UK it is nearly 10,000 kg per person per year.
This pie chart shows what contributes to the carbon footprint of a typical person living in an MEDC.

13. Exercise 1
Attempt the carbon calculator worksheet and find out your carbon footprint.
Answer the questions to consider how you can reduce your carbon footprint.

14. Carbon footprints and energy production- non renewables

15. Carbon footprints and energy production- renewables

16. Exercise 2
Attempt exercise 2 in your class booklets. Use the notes section to help you.

17. Calculating the carbon footprint of emission gases
KgCO2eq= (mass of a gas) x (global warming potential of the gas)
Global warming potential (GWP) is a relative measure of how much heat a greenhouse gas traps in the atmosphere. It compares the amount of heat trapped by a certain mass of the gas in question to the amount of heat trapped by a similar mass of carbon dioxide.

18. Calculating the carbon footprint of emission gases- exercise
Attempt exercise 2 in your booklets.

19. Calculating the carbon footprint of emission gases- exercise answers
What is the KgCO2eq of the following:
A ten mile car journey that produces 3.3 Kg of carbon dioxide (CO2):
KgCO2eq= 3.3 x 1= 3.3
Global landfills that emit Kg of methane (CH4) per year:
KgCO2eq= x 21=

20. Lesson aims- End of lesson checkpoint
The terms ‘sustainable’ and ‘carbon footprint’ when applied to generation of electricity or the use of electricity and energy (e.g.natural gas)
Explain what a carbon footprint is.
How can you be more sustainable?
The measurement of the carbon footprint in terms of mass equivalent of carbon dioxide (kgCO2eq) and global warming potential of a gas; the use of the relationship: kgCO2eq = (mass of a gas) × (global warming potential of the gas)
What is the kgCO2eq of 10Kg of nitrous oxide?