Travel is often a major component of our personal carbon footprint, so there is considerable scope for lifestyle changes to minimise our CO2 emissions. The most obvious one is whether we own or use a car and if so what type.
Table 1 below shows the total carbon emissions for some popular cars. The total is made up of the embedded CO2 required to make the car, divided by its life, and the CO2 emitted over a year’s travel. The cars are assumed to last 13.5 years and be driven 7,500 miles (12,070 km) per year. The VCA emission results are laboratory tests, so are an underestimate of actual fuel and CO2 emissions.
Table 1. Annual CO2 emissions plus embedded CO2, for cars having a 13.5 year life and driving 7,500 miles per year
|Make||Model||Engine size (L) & fuel||Weight
|Annual Embedded CO2
|BMW||X 3||2.0 D||1.750||0.808||161||1.943||2.75|
|Range Rover||Sport||3.0 D||2.115||0.977||185||2.233||3.21|
|BMW||X 6||4.4 D||2.265||1.046||258||3.114||4.16|
Embodied energy 90,000 MJ/tonne, CV diesel 45.5 MJ/kg, CO2 produced per kg diesel 3.15 kg. http://energyskeptic.com/2015/how-much-energy-does-it-take-to-make-a-car-by-david-fridley-lbl/
The message is that smaller cars compared to larger ones emit less CO2 and are therefore more environmental. If one owns a car, it’s footprint per person is reduced if it: –
- Carries more than one person
- Is just used for shopping, day trips, holidays, and snowy days
- Is not used for commuting
Leaving the car at home and walking or cycling to work reduces carbon emissions but you are still responsible for the embedded carbon used to make the car.
In societies present mindset, the status of a car owner increases as its carbon footprint increases. This must change as the risks of climate change becomes more widely recognised.
We are all guilty of unconscious bias towards status. If we hire a consultant at £1000 per day and he turns up in a Honda Jazz, we may wonder if he is going to give us good advice.
Electric cars and hybrids
This section is in development and will be available soon. (Todays date is 21/3/18)
In the meantime, click on Low Emission Cars to review the range of cars that are on the market.
There are several different car share schemes in the UK. The one which operates in Aberdeen is Co-wheels . It is the largest car share company in the UK, with cars in 60 different cities. It is a social enterprise company.
Co-wheels started in Aberdeen in spring 2012, and there are now well over 1000 people using it. The fleet has a total of 34 vehicles available, including two vans. The cars vary in size from a small 4-door to an estate. Eighteen of the vehicles (including the two vans) are electric and five are hybrids. The cars are parked in marked bays on various streets around the City.
How does it work?
- Joining fee £25. A check is made that you have a valid driving licence. Insurance is covered. You will be issued with a smart card which gives you access to the cars.
- There is a minimum fee of £5/month. If you use a car during that month, the £5 is deducted from the cost. So, even if you never use the scheme, it will only cost you £60 for the year.
- Book on line or over the phone. Choose the car you want and the time you want. You can book for any hire time from ½ hour to a week (assuming the car is available).
- The cost is made up of the hire cost and a fuel cost. For the smallest car the hire cost is £4.75 for one hour, rising to £33.25 for 24 hours, and the fuel cost is 18p/mile. There is no fuel charge for electric cars.
- You collect the car directly from its parking bay. Within your booked time, your smart card is recognised by a computer situated on the inside of the front windscreen, and the car will unlock. The car keys are then situated in the front glove compartment and you can just drive away.
Advantages of the scheme
- Economic. You do not have to pay for road tax, insurance, servicing, and MOT, so that your annual car driving will probably cost you hundreds rather than thousands of pounds/year. Also you do not incur the cost of depreciation if you sell your own car.
- No hassle of maintaining, servicing and cleaning your own car.
- Use UK-wide. You can book any Co-wheels car throughout the UK, so that you can travel by train to a distant place (which has Co-wheels cars, of course!) and hire a car while you are there.
- There is a 24-hour phone hotline available if you encounter any problems. This can also be accessed from the on-board computer.
- Reduction of carbon emissions. You will have saved the carbon emissions due to the manufacture of one car solely for your own individual use. You will continue to save carbon emissions as you use public transport, cycling and walking in conjunction with the shared car.
Disadvantages of the scheme
- Pre-planning required. You cannot just jump into a car in your driveway when you want it. You have to book in advance, and perhaps the car you want is not available exactly when you want it. Also you have to collect it from a designated parking bay so you need to go (bus? cycle? walk?) to this place.
- Car not available to drive at booked time. There is the possibility that the previous person hiring the car has not returned it on time, or to the correct parking bay, or that the car keys are not in the glove compartment. By contacting Co-wheels they will do everything they can to sort out this problem.
In considering the carbon footprint of public transport, flying is by far the worst (Table 2). Our interconnected world means that many people who have family in distant parts are torn between looking after the environment and seeing loved ones. To allow them to keep flying, it is beholden for others in business or going holidays, to keep flying to the minimum.
Table 2. Carbon footprint from flying from London to various destinations
|Destination||Distance||Fuel used per passenger (return)||Carbon footprint
(tonne CO2 eq per passenger)
|New York (L Haul)||3,455||414||3.86|
|Sydney (L Haul)||10,557||1,196||11.15|
Source: – www.chooseclimate.org air travel calculator
The air travel calculator (Table 2) gives equivalent carbon footprints, which are 2.7 times the actual CO2 emissions. Emissions of CO2 at altitude have almost three times the global warming effect as emissions at ground level. The lower rate of fuel used per mile on the long-haul flights is because cruising fuel consumption is considerably less than that during take-off.
Whatever way you look at these figures, we should avoid flying if at all possible, especially to distant holiday destinations.
Train and bus
Comparable carbon footprints for public and private transport are shown in table 3.
Table 3. Relative CO2 emissions by public transport and car
(kg CO2 eq/mile)
|Car||Citron , C1||0.344||Driver only|
|Car||Average sized e.g. Ford Focus car||0.710||Driver only|
|Air||To Hong Kong||0.747 +|
Ref: How bad are bananas, Mike Berners-Lee, pp239, Profile Books. 2010.
+ Assumes extra impact of CO2 emissions at altitude is 1.9 times.
Travelling by rail or bus, or sharing a car, minimise your carbon footprint.
Walking and going by bike rather than car
Using a car weighing between 1,500 to 2,000 kg to transport a 60-90 kg person around town is obviously inefficient and a wasteful use of precious fuel. Use it by all means to transport families or groups on longer trips for days out or holidays, but avoid using it for daily commuting. Walk, bike or take public transport instead. Safe cycling should become a norm.
The lowest carbon footprints are to walk or go by bike. There are no issues with walking other than the journey being too far to walk in the time available.
Cycling in comparison has four issues, safety, effort, road conditions and sweat.
Safe cycling must be learned. The leaflet Safe cycling in town, gives basic guidance. If you are unhappy about cycling on the road, Google maps show the best ways of going from A to B by bike. These will include cycle lanes where these are available.
In flat areas, sheltered from wind, effort is minimal. If there are many hills or exposed routes, 21 gears and a lightweight bike are to be recommended. If you become a regular commuter it is simply amazing how quickly your fitness will improve, until you hardly notice hills. If you do find the effort too much, get an electric bike.
In wet or snowy weather, wear clothing that will not matter if it gets grimy. Alternatively take a bus in these conditions.
Some people do not like turning up at work all sweaty. If this is an issue, miss your shower at home and have it at work instead.
The joy of cycling
Once you have overcome any apprehension about cycling on roads and are fully fit, cycling really is a joy. Any cobwebs accumulated during a day in the office are dispersed on the way home. Not only can you save the planet but you can enjoy the ride.