Transport emissions

Cars

1. First look to the type of car you have; whether it runs on petrol or diesel, and what the size of the engine is.
2. From this you can work out the approximate amount of CO2e emissions it releases. You can either work this out in terms of the litres of fuel it uses, or by the distance travelled.

NB: remember that speed will also play a role in the amount of carbon emissions that you emit.
Click here to see a graph of the speed efficiency in miles per gallon.

		kg CO2 per km	kg CO2 per mile	kg CO2 per litre	kg CO2 per gallon
Petrol	Small (max 1.4 litre )	0.16	0.26	2.3	10.46
	Medium (1.4 - 2.1 litre)	0.19	0.30
	Large (above 2.1 litre)	0.22	0.35
	Average	0.18	0.29
Diesel	Small (max 2.0 litre)	0.16	0.26	2.63	11.96
	Large (above 2.0 litre)	0.19	0.31
	Average	0.17

Source

Other forms of transport:

		Emissions (kg CO2)
		(per km)	(per mile)
Air	Short haul	0.11	0.18
	Long haul	0.18	0.24
Rail		0.04	0.06
Bus / Underground / Local transport		0.1	0.17
Coach / long bus journey		0.05	0.08

Sources 1, 2, 3,

Comparison of emissions from cars and public transport:

** Please note that these calculations are approximate and simply have the primary purpose of showing how to use the figures from the above tables. **

Example 1: The school run - a ten mile trip, ten times a week for thirty eight weeks (a typical state school year).

Average petrol car:

Per journey:
0.29 (kg CO2 per mile) x 10 (miles) = 2.9 kg CO2
Per year:
2.9 x 10 (journeys a week) x 38 (weeks) = 1102 kg CO2

Public bus:

Per journey:
0.17 (kg CO2 per mile) x 10 (miles) = 1.7 kg CO2
Per year:
1.7 x 10 (journeys a week) x 38 (weeks) = 646 kg CO2

School coach:

Per journey:
0.08 (kg CO2 per mile) x 10 (miles) = 0.8 kg CO2
Per year:
0.8 x 10 (journeys a week) x 38 (weeks) = 304 kg CO2

Example 2: Visiting relatives - 380 mile round trip (e.g. Leeds to London) six times a year.

Average petrol car:

Per journey:
0.29 (kg CO2 per mile) x 380 (miles) = 110.2 kg CO2
Per year:
110.2 x 6 (times a year) = 661.2 kg CO2

Train:

Per journey:
0.06 (kg CO2 per mile) x 380 (miles) = 22.8 kg CO2
Per year:
22.8 x 6 (times a year) = 136.8 kg CO2

Coach:

Per journey:
0.08 (kg CO2 per mile) x 380 (miles) = 30.4 kg CO2
Pet year:
30.4 x 6 (times a year) = 182.4 kg CO2