Environmental Engineering Reference
In-Depth Information
but the aggregate effect of this will be offset as population will have increased in London.
The main reduction has not taken place in the number of trips made, but in the length of trips.
The distribution has hence changed, with some growth in long-distance trips, but these are
more than compensated for by the increase in shorter more local trips. The desire for less
travel (and distance for freight distribution) links in with the greater social awareness and
conscience of the population, and the importance of community and welfare objectives. The
'lock-in' to car dependency (as found in image 1) is broken with social priorities pushing for
greater use of public transport and other clean modes of transport. Walking and cycling levels
are similar to those found in the Netherlands, in Gröningen, Delft and Amsterdam - so
30 per cent of trips are made by bicycle. The vehicle fleet becomes much cleaner to 2025,
through new taxation and pricing incentives to use more efficient and cleaner technologies,
with tax reductions for not owning a car or for participating in car sharing or different ownership
schemes. Car clubs and new forms of ownership are encouraged because of the wider societal
benefits. Real fuel prices increase over the period; increases in oil prices are an effective
enabler to achieving carbon efficient transport.
This level of policy implementation is the scale of change required to achieve the overall
target of 0.5 tCO2 emissions from transport per capita per annum. The very positive news is
that the transport sector can de-carbonise in a city such as London to these levels, at least in
theory. The scenario pushes extremely hard on all of the available policy levers and implements
all technological and behavioural options to a relatively high intensity level. It envisages very
high levels of walking and cycling. An important feature is that car distance reduces in Scenario
4 (and 3) - overall distance is broadly held constant, with the difference taken up by a very
large increase in walking and cycling. The large difficulty is in achieving the assumptions
within the modelled scenarios. This relates to technological and behavioural options. The
rationales for achieving greater efficiencies in vehicle emissions and individual mobilities and
behaviours hence need a very serious examination - from this knowledge we can perhaps
improve our levels of policy implementation and effectiveness. A number of points are made
against the assumed levels of policy package application under each package in Scenario 4.
PP1 low-emission vehicles:
The take up of low-emission vehicles, based largely on hybrid
technology, is likely to be very important to reducing emissions. Because most transport CO2
emissions derive from the car fleet, the achievement of targets is greatly reliant on the
penetration rates of low-emission vehicles into the fleet, supported by efforts to induce mode
share and changed trip distribution (shorter travel distances). Full introduction of an average
car fleet of <100 gCO2/km by 2025 and/or 2050 requires substantial investment by car
manufacturers and changes to consumer purchasing patterns; hence the technological and
behavioural aspects are very closely interrelated.
The current best generations of new vehicles have emissions levels of around 100 gCO2/km
(the Toyota Prius hybrid emits 89 gCO2/km; the Volkswagen Polo Blue Motion diesel emits
91 gCO2/km). Relying on the low-emission vehicle option may be high risk as there is no
guarantee that the vehicles will penetrate the market to any great degree. The current consumer
preference (in the mass market) is for higher specification and heavier vehicles, which emit
more CO2. Recent reductions in average fleet CO2 emissions have largely been due to
dieselisation rather than the introduction of hybrids. There are major issues concerning the
costs and feasibility of converting the whole of the London car fleet to hybrids, and a poor
understanding of incentives required to allow mass-market take up. Influencing the motor
manufacturers as to which vehicles and technologies they develop is difficult; with the current
business model very much focused on selling the ICE petrol car, with some limited effort in
