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Transport

Transport scenarios focussed on personal transport only. Personal transport accounted for 10% of the South West's total ecological footprint in 2001. The scenarios shown here will look at modal shifts, in other words changes in the way residents travel, as well as increases and efficiency in travel.

As with the waste scenarios, a number of scenarios were developed for transport. Not all of these are presented here, but the remainder can be found in Additional Information.

Biofuels

In 2001, 28,600 million kilometres were travelled by cars in the South West, with a further 398 million kilometres travelled by motorbike (Espineira & Haslam, 2002; Pathan, 2004 and Salathiel, 2003). Transport energy use is projected to grow by 2% per year, with a corresponding increase in greenhouse gas emissions (DTI, 2000). To limit greenhouse gas emissions from this sector, the European Commission (2003) has set a minimum target for each member state to replace 5.75% of all petrol and diesel consumed (by energy content) with biofuel (or other renewable fuels) by 2010. Further information on biofuels can be found in Additional Information.

Scenario 1: Optimum mix to meet European target of 5.75% biofuels

How would the biofuels ecological footprint change with a change in the biodiesel/bioethanol mix?

The following variables were assumed:

  • A 2% annual increase in passenger kilometres travelled by car and motorbike from 2001 to 2015.
  • All motorcycles run on petrol, and 52% of cars in 2010 will use petrol, compared to 57% in 2001 (DTI, 2000).
  • Fuel consumption values for cars and motorcycles were taken from Energy Consumption in the UK (DTI, 2000).
  • The average car is four years old.
  • All the biofuels needed will be produced in the South West.
  • Coefficients for land requirements and plant costs come from the SAFIRE model (ESD, 2004).

The area of land required to provide this amount of biofuels depends upon the fuel replacement mix. If only biodiesel was used to meet the target, this would require 128,000 hectares of land (24% of the South West's available land) for growing biofuel energy crops. However, if only bioethanol was used to meet the target, this would require 30,000 hectares of land (6% of the South West's available land) for growing biofuel energy crops.

Table 18 illustrates the change in the ecological footprint as the proportion of bioethanol increases in the biofuel mix. Bioethanol has a lower ecological footprint than biodiesel. The mix selected will have implications in terms of cost, for plants to process the fuel, and land required; bioethanol gives a greater yield in terms of litres of fuel per hectare per year.

Table 18
Ecological footprints of different bioethanol and biodiesel mixes for the South West, in 2015
 
Proportion of bioethanol (%) Total biofuel (million litres) Plant costs to produce in the South West (£m) Land required ('000 hectares) Ecological footprint per person (gha)
0 152 13 130 0.14
20 152 16 110 0.12
40 152 18 90 0.10
60 152 21 70 0.07
80 152 24 50 0.05
100 152 26 30 0.03
 

Scenario 2: One planet lifestyle mix

How large would the biofuels ecological footprint be if 100% of car, taxi and motorbike travel was fuelled by bioethanol?

Units

Kg CO2 eq: Kilogrammes of carbon dioxide equivalent.
GJ: Gigajoules, i.e. 1,000,000,000 joules.
Odt: Oven dried tonne.
Ha: hectare.

The following variables were assumed:

  • Passenger kilometres travelled by car, taxi and motorbike from 2001 to 2015 remain at 2001 levels.
  • All motorcycles and cars run on 100% biofuels.
  • All the biofuels needed to run cars, taxis and motorcycles will be produced in the South West.
  • Coefficients for energy requirements were taken from Hart et al. (2003) and assume bioethanol produced from short rotation coppice. Carbon emissions account for fossil fuel inputs to biomass production and transport and range from 4 to 90 kg CO2 eq/GJ. An average of 47 kg CO2 eq/GJ was used.
  • Coefficients for land requirements were taken from Hart et al. (2003) and assume a yield of 15 odt/ha/yr and an energy content of 18 GJ/odt.

It would take almost 292,000 hectares (an ecological footprint of 0.31 gha per person) to produce enough bioethanol to fuel all South West cars, taxis and motorbikes travelling an annual amount equivalent to 2001. This is more than 54% of the arable land in the South West. Hart et al. (2003) state that the UK land availability for short rotation coppice by 2050 will be 25% of 'agricultural' land. It is also worth considering that the present supply of bioethanol for transport use in the UK is zero (Hart et al., 2003).

Base case

In 2001, South West residents travelled an average of 11,416 passenger kilometres (pass-km). Car travel was the most common form of transport, 85% of total distance travelled (see Table 19). The ecological footprint of transport in the South West in 2001 was 0.53 gha per person.

Table 19
Base case distances travelled by residents in the South West, by mode, in 2001
 
Mode Pass-km % of total pass-km
Total distance per person 11,416  
of which…  
Walk & cycle 352 3%
Car (incl. taxi) 9,664 85%
Bus & coach 253 2%
Rail, tram and metro 413 4%
Waterborne 139 1%
Air* 514 5%
Motorbikes &scooters 81 1%
* Air travel data presented in Table 14 of the Resource Flow Report is for 2001.
The estimate used in this table and for the scenarios, uses the same proxy of UK average air travel as in Table 14 of the Resource Flow Report (70%), but is based on older UK average data (1999).
1999 data was used in the tool used to calculate the scenarios as the UK default, and was retained for consistency with travel estimates in other ecological footprint studies.
Note: The travel modes listed in this table are aggregated from modes shown in Table 14 in the Resource Flow Report [hotlink].
Note: Totals may differ due to rounding.
Sources: Espineira & Haslam, 2002; Pathan, 2004 and Salathiel, 2003

Leisure and commuting to work were the most common reasons for travelling - see Figure 10.

Figure 10
Base case distances travelled by residents in the South West, by purpose, in 2001

fig 10

* Other includes trips to the bank or visits to the doctor.

Scenario 1: Commuting by car to work

What if car travel reduction targets were achieved for commuting to work, while other modes (walking, cycling, bus and rail) were increased, effectively achieving a modal shift in travel?

The following conditions were assumed:

  • Overall distance travelled remains the same as 2001: 3,230 pass-km commuter travel, 11,416 pass-km total travel per person.
  • Air travel was not considered for this scenario.

Table 20 part A shows the results of Scenario 1 for commuter travel, part B shows the results for total travel.

Table 20
Estimated distances travelled by commuters in the South West, based on car reduction targets, in 2001
 
Part A: Commuter travel
Mode Commuter base case pass-km Commuter base case % Commuter Scenario 1 pass-km Commuter Scenario 1 %
Total distance per person 3,230 100% 3,230 100%
of which…  
Walk 24 1% 355 11%
Cycle 29 1% 129 4%
Car (incl. taxi and other)* 2,636 82% 1,915 59%
Bus & coach 59 2% 194 6%
Rail, tram and metro 210 7% 365 11%
Waterborne 50 2% 50 2%
Air 185 6% 185 6%
Motorbikes &scooters 37 1% 37 1%
 
Part B: Total travel
Mode Total base case pass-km Base case % Total Scenario 1 pass-km Scenario 1 %
Total distance per person 11,416 100% 11,416 100%
of which…  
Walk & cycle 352 3% 784 7%
Car (incl. taxi and other)* 9,664 85% 8,943 78%
Bus & coach 253 2% 387 3%
Rail, tram and metro 413 4% 568 5%
Waterborne 139 1% 139 1%
Air 514 5% 514 5%
Motorbikes &scooters 81 1% 81 1%
* This category includes vans and caravans.
Note: Totals may differ due to rounding.
Sources: Bath & NE Somerset, 2000; Cornwall County Council, 2000; Espineira & Haslam, 2002; Pathan, 2004 and Salathiel, 2003
  • Reducing car travel from 80% of commuter travel (2,636 pass-km per person) in 2001, to 57% (1,915 pass-km per person), would reduce overall car travel from 9,664 to 8,943 pass-km per person per year.
  • Bus travel would increase from 2% to 6% of commuter travel (59 to 194 pass-km per person per year), increasing overall bus use from 253 to 387 pass-km per person per year.
  • Train use would increase from 7% to 11% of commuter travel (210 to 365 pass-km per person per year), and overall train travel in the South West would increase to 568 pass-km per person per year.
  • Walking would increase from <1% to 11% of commuter travel (24 to355 pass-km per person per year), increasing overall walking to 618 pass-km per person per year. (Based on Cornwall County Council Local Transport Plan 2001-2006 target of 11% of commuters living in rural areas to walk to work (Cornwall County Council, 2000).)
  • Cycling would also increase from 1% to 4% of commuter travel (29 to 129 pass-km per person per year), increasing overall cycling from 66 to 166 pass-km per person per year. (Based on Bath and NE Somerset Local Transport Plan 2001-2006 target of 4% of people cycling to work (Bath & NE Somerset, 2000).)
  • Overall, walking and cycling would increase from 352 to 784 pass-km per person per year.
This scenario gives a transport ecological footprint of 0.51 gha per person, a reduction of 0.03 gha per person (4%) from the base case.

Scenario 2: Car and air travel reductions

What if overall travel was reduced by reductions in car and air travel, without increasing other travel modes?

Most local travel plans across the South West have targets for reducing car travel for particular purposes - a common area of focus appears to be travel to school. Travel targets for other modes of transport such as rail or bus all aim at increases. This scenario was based on local travel plan targets but will only reduce travel by car and air.

The following variables were assumed:

  • Overall distance travel is reduced from the 2001 base case of 11,416 pass-km to 8,685 pass-km per person.
  • Car travel is reduced by 25% from 9,664 pass-km to 7,910 pass-km per person.
  • Air travel is reduced by 50% from 514 pass-km to 257 pass-km per person.

This would mean a reduction in car travel as driver from 5,792 pass-km in 2001, to 4,003 pass-km, and in car travel as passenger from 3,582 pass-km in 2001 to 2,898 pass-km. Air travel would be halved (from 514 to 257 pass-km), while the remaining travel modes remain as base case. Table 21 shows the results of Scenario 2.

Table 21
Estimated distances travelled by residents in the South West, based on car and air reduction targets, in 2001
 
Mode Base case pass-km Scenario 2 pass-km
Total distance per person 11,416 8,685
of which…  
Walk & cycle 352 352
Car (incl. taxi and other)* 9,664 7,190
Bus & coach 253 253
Rail, tram and metro 413 413
Waterborne 139 139
Air 514 257
Motorbikes &scooters 81 81
* This category includes vans and caravans.
Note: Totals may differ due to rounding
Source: Bath & NE Somerset, 2000; Cornwall County Council, 2000; Espineira & Haslam, 2002; Pathan, 2004 and Salathiel, 2003

Scenario 2 reduces the base case transport footprint by 0.15 gha to 0.39 gha per person, a reduction of 26% on base case.

Scenario 3: Improved car technology

What if there is an improvement in the fuel efficiency of the South West's car fleet, from current average fuel consumption to the best currently available?

Although a number of technological innovations for reducing the impact of car travel and fuel use in particular are in development, few are yet commercially available. Current efforts to reduce CO2 emissions and improve vehicle efficiency include the use of alternative fuels, for example:

  • liquid petroleum gas (LPG), which achieves 10-30% CO2 reductions compared to petrol
  • biodiesel which is blended with diesel up to a current manufacturers' limit of 5%, achieving approximately 3% less CO2 than conventional diesel, 10-20% less than petrol (Hart et al., 2003).

The following variables were assumed:

  • Travel by mode as the 2001 base case. See Table 20 base case for distances travelled.
  • 2001 average fuel efficiency of 10.75 km/l (30.36 mpg) (DfT, 2002) giving CO2 emissions of 1,083 kg per person.
  • Best currently available fuel efficiency 29.41 km/l (83.1 mpg) for the Honda Insight (Vehicle Certification Agency, 2004) giving CO2 emissions of 392 kg per person.

This would reduce the South West's transport ecological footprint by 0.27 gha (50%) to 0.27 gha per person. CO2 emissions would fall from 1,083 kg to 392 kg per person.

Scenario 4: One planet lifestyle

What further measures would be required to achieve environmentally sustainable transport use in the South West?

This scenario is an attempt to meet environmental sustainability criteria. The criterion used for this scenario is the 'earthshare', taken from the National Footprint Accounts (Redefining Progress, 2002), which assumes the human race lives within the natural limits of our planet. With the current ecological footprint of a South West resident at 5.56 gha/person, an overall reduction of 66% is required to meet the earthshare criterion.

The following variables were assumed:

  • Travel modes as Scenario 2 (reduced car and air travel). See Table 20 for distances travelled.
  • 2001 average fuel efficiency of 10.75 km/l (30.36 mpg)(DfT, 2002) and CO2 emissions of 972 kg per person.

All vehicles replaced by hydrogen fuel cell vehicles with zero CO2 emissions, powered by renewable, short-rotation coppice produced fuel. Bioproductive land is required to grow the short-rotation coppice biomass.

Reduction of the ecological footprint

The transport scenarios display possible variations in the estimated transport ecological footprints. These reflect various changes in modal shift and technology. The ecological footprints for each of the transport scenarios are illustrated in Figure 11.

Figure 11
Personal transport base case and scenario ecological footprints for the South West, in 2001

fig 11

Sustainable resource consumption and production: Ecological footprinting as the link between resource efficiency and sustainable consumption

'Sustainable' production

The ecological footprint is proving to be a compelling indicator of sustainable consumption. It has two key features that make it so powerful:

  • It aggregates consumption of a wide range of resources (both energy and materials).
  • It can be used to compare resource consumption (the ecological footprint) with globally available resources (the earthshare) to illustrate what level of consumption is sustainable.

Can ecological footprinting also be an indicator of 'sustainable' production?

The ecological footprint can effectively be used to aggregate the impact of resources consumed in the production process to provide a resource efficiencymetric per unit of production. It is possible to compare the ecological footprint of 'product A' with 'product B' or with the per person average earthshare. It is also possible to show how much of the ecological footprint per person is attributable to the consumption of 'product A'. But, while a company or product may be increasingly eco-efficient, no single product or company can, in itself, be sustainable.

Sustainability is a function of

  • Impacts from all activities of all populations
  • Impacts throughout the lifecycle
  • Comparison of all those impacts with available resources.

All of these factors must be taken into account when analysing sustainability. So, the ecological footprint can be a useful resource efficiency metric, but sustainability does not apply to production, only to consumption.

Resource efficiency

Can ecological footprinting be used to indicate the most resource efficient way of manufacturing a product?

By including a wide range of energy and material resources, ecological footprinting can be used to compare the aggregate resource efficiency of producing similar products. For example, if one company is able to produce steel with a lower embodied carbon (say, 0.57 tonnes of carbon per tonne of steel) than another (say, 0.63 tonnes of carbon per tonne of steel), the steel from the first company would have a lower ecological footprint, and it would be desirable to source steel from there. Perhaps two comparable nappies use differing amounts of wood fibre and plastics. Ecological footprinting can indicate which one, overall, is the most resource efficient. This can be useful in identifying and encouraging best practice in resource efficiency, or in responsible procurement processes. This should be of interest to policy makers and business support programmes at the regional, national and global levels.

Can ecological footprinting be used to indicate the most resource efficient way of providing a service?

By accounting impacts throughout the lifecycle (in production and use) and normalising them to 'service units', ecological footprinting can indicate the most resource efficient way of providing a service, for example, travel by car. Ecological footprinting can be applied to the manufacture of the car providing the travel services.

The direct energy used to build a Honda, in Swindon in 2001, had an ecological footprint of 0.17gha*, but the footprint of the energy consumed in manufacture was about 6% of that throughout the lifecycle of the car, assuming average South West use. Another car may be more resource efficient in manufacture, but less efficient in use. A third car may be less resource efficient in manufacture but more so in use. The ecological footprint per vehicle-kilometre is dependent on both manufacture and use efficiency.

Can ecological footprinting be used to indicate the most resource efficient way of creating economic wealth?

As an aggregate resource consumption indicator, ecological footprinting can be used alongside economic indicators such as GDP or GVA, to estimate the most resource efficient way of generating economic wealth. For example, the tourism industry in the South West has an annual ecological footprint of 2,036,375 gha and generates £2,439 million of GVA. (£1,198/gha). The motor manufacturing plant run by Honda in the South West has an estimated ecological footprint of 296,101 gha, and generated an estimated £160 million of GVA (about £542/gha).

This is of interest to economic development agencies charged with encouraging industries with low resource intensities within their economic base. However, it should be noted that if society consumes products and services with higher resource intensities, these must be manufactured somewhere. There is always the possibility that although a population sources low intensity products from the domestic economy, it will source high intensity products from elsewhere – the impacts are still incurred, but have been exported – a process sometimes referred to as 'burden shifting'. As sustainability is a global property, this approach will not improve the sustainability of the population.

Can ecological footprinting be used to assess whether a product or service, business or sector is 'sustainable'?

A product or service cannot be defined as 'sustainable' in itself, but the ecological footprint can be used to indicate whether the resource efficiency of a product or company is improving or declining. Ecological footprinting can also be used to determine the scale of the contribution of a product or service to sustainable resource consumption. For example, services provided by the NHS in England and Wales consumed 2% of the total ecological footprint per person in 2001, and 5% of the average earthshare. Clearly it is necessary to apply ecological footprinting across all activities to enable this comparison.

* Calculated based on data from Honda's Safety & Environment Report (Honda, 2001).