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The most important conclusion to draw from the model-based integrated analysis of GHG-TransPoRD is that the -60% GHG reduction target for the transport sector is fea-sible to achieve by 2050 as opposed to 1990. Obviously the target is ambitious such that most of the scenarios and policy packages tested by GHG-TransPoRD failed to deliver the required reductions. However, the scenario analysis concluded that scenarios combining:

  • fast development of efficiency technology,
  • alternative engine technologies able to build their energy supply on renewable electricity,
  • ambitious policy-making to counterbalance rebound effects and maintain financial stability of government transport revenues,
  • ambitious regulation phasing out fossil fuel cars around 2035 together with a moderate modal-shift from road towards more energy efficient modes, and
  • adaptation of the electricity system to become largely renewable based
will enable to achieve these targets. Such a scenario was developed and tested in the ambitious regulation scenario (AMB_REG) by GHG-TransPoRD. Sensitivity analyses confirmed that with higher oil prices than underlying our analyses even more stringent GHG reduction targets could be achieved.

Road transport, and in particular car transport, has to deliver the largest absolute reductions of energy demand and GHG emissions. With more than 90% of domestic transport GHG emissions accounting for road transport this is obvious, as well. However, as road transport, and again in particular cars and light duty vehicles, disposes of the largest potentials to both reduce energy demand and to switch to low-carbon or carbon-free energy sources these two findings of GHG-TransPoRD are consistent and fit together.

The Intergovernmental Panel on Climate Change (IPCC) and the International Energy Agency (IEA) both emphasize the requirement for a peak of GHG emissions during the current decade until 2020. This means early reductions of GHG emissions from European transport will be preferential compared with later reductions. In the next two decades only road mode will be able to contribute both significant and early GHG reductions. The other modes will mainly rely on operational measures to reduce their GHG emissions during that period due to slow fleet turnover. This can be identified by the maximum efficiency at market conditions scenario (Max_E&M), which is designed to implement the most effective efficiency technology in a fastest and market-driven way, in what concerns technology choice. Until 2020 it generates close to 46% more reductions than the EV scenario, 60% more than the HFC scenario, and 24% more than the combined EC+HFC scenario. The driver of this reduction is massive introduction of efficiency technology of road vehicles to be either driven by the climate mitigation awareness of the automotive industry or by setting of strict CO2 emission standards through European and global legislation. To ensure achieving the target, policy-makers should choose the second option.

However, our analysis revealed that around 2035 fossil fuel based conventional cars need to be banned from the European market completely to achieve the -60% reduc-tions until 2050. Only with such a policy the alternative technologies like EVs, FCEV and PHEV would diffuse into the market fast enough, and from todays’ point of view doubts must be raised if this would happen without such a ban. But this means, over the next 10 to 15 years investments into efficiency technologies of conventional fossil fuel cars need to be substantial, despite these vehicles could only be sold some 20 years longer. Of course, some innovations like light-weight design and improved aerodynamics can be implemented into any car independent from its engine technology. Other technologies constitute transitory techniques that bridge to the development of alternative fuel vehicles (e.g. CNG/biogas cars), while there would probably also be improvements of the combustion engines, which can not be applied anymore when conventional cars are phased-out. The challenge to identify those technologies that improve efficiency most effective and can be applied longer into the future as well has to be solved by the automotive industry, in particular after 2020.

The A(S)IF analysis of the ambitious regulation scenario (AMB_REG) demonstrates that looking at the full period until 2050 during the first two decades the reduction of energy intensity (in other words improvement of energy efficiency) constitutes the dominating source for reductions of GHG emissions, while between 2030 and 2050 the reduction of carbon intensity, in particular through electrification of transport and the parallel transition of electricity production to a renewable based system, will be the dominating source of GHG reductions. In short, first capture fast the energy efficiency potentials and than focus on the carbon-free energy potentials.

However, this should not be understood in a way that alternative fuel vehicles should not be developed and brought to the market in the first two decades. But considering that even in the automotive industry, being the sector with the biggest R&D budgets in Europe, these budgets are limited and investments need to be prioritised. Then priority at least in this decade should be given to efficiency improvements, while from the climate mitigation point of view alternative fuel vehicles (in particular EVs and FCEVs) could receive a lower priority. This should by no means lead to a halt of their development, but rather to a shift of their massive introduction to a few years later as this seems to be reasonable, at least under a constrained investment budget. Nevertheless, it must be ensured that these vehicles get onto their learning curve, e.g. by selling them only to early adopter markets, which in the case of EVs would be fleet operators in certain sectors, instead of intending to sell them to a mass market from the beginning of market diffusion. Such specific markets should also be considered when designing policies to foster alternative fuel vehicles.

Efficiency improvements of road transport in climate mitigation scenarios will be much faster than increase of energy prices. Thus in all scenarios that do not counterbalance efficiency gains by increasing other transport cost (e.g. fuel duties, road tolls, urban road charges) very strong rebound effects have been found leading to a significant modal-shift towards road transport and away from the more efficient rail mode and public transport. Such a rebound effect may cannibalise a significant part of the GHG savings, such that counterbalancing measures need to be taken. Thus in our more ambitious scenarios fuel duties have been increased and urban road charges introduced such that in total the scenarios generated higher GHG emission reductions than the scenarios without such measures.

Increasing road transport taxes and tolls brings about the co-benefit that government revenues from the transport sector are stabilised, while pure efficiency and alternative technology scenarios deteriorate the government revenues from the transport sector, which in turn at least partially is required to fund infrastructure and operation within the transport sector e.g. for railway infrastructure and public transport.

Biofuels could supply about 40 to 50 Mtoe of transport energy demand. The peak of their supply and demand in the different scenarios would be during the decade 2030 to 2040. After 2040 the demand for biofuels is reduced, driven by decreasing demand from road transport. However, for air transport the use of biokerosene constitutes the main option to significantly reduce its GHG emissions. Therefore GHG-TransPoRD suggests to emphasize R&D for use of biofuels in air transport as well as to ensure that in case biofuel and biomass supply gets limited their use in air transport is prioritised.

Finally, it should be noted that the scenario achieving the -60% reduction target poses an abatement cost on transport users and corresponding a minor reduction of GDP growth but on the other hand it reveals a negative abatement cost for the society, or in other words an abatement benefit.