Problem shifting in transport systems. Analysing and balancing unintended consequences of CO2 emission reduction in Dutch transport.

Summary Transport systems face significant input- and output-related challenges in the upcoming decades. To tackle climate change – the major output challenge - an 80% CO2 reduction has to be achieved by 2050 (base year 1990). This requires a sustainability transition to low-CO2 passenger mobility and freight transport. Problem shifting – the occurrence of unintended/indirect consequences – is expected, if the sustainability transition is not properly governed. The results are potential societal disruptions and/or resource scarcity impacts. This study assesses CO2 reduction measures for the Dutch transport system concerning their unintended consequences and describes policy implications as an essential pre-condition for a future-proof transport system. The following methodology has been applied: 1. Identification of potential measures to reduce CO2 emissions in Dutch transport 2. Qualitative assessment of all measures concerning their indirect consequences 3. Quantification of scenario-specific unintended consequences through application of a bottom-up calculation model (assessment of five published strategies) 4. Development of optimized long-term strategy to minimize and balance unintended consequences of CO2 reduction in Dutch transport All identified measures generate multiple unintended consequences – varying in quality and scale. The severity of unintended consequences depends on different inter-connected aspects, such as the scale of implemented measures, the combination of different measures and the socio-economic and cultural context. The assessment of five recently published strategies on CO2 reduction in transport has shown that societal disruption and/or resource scarcity might occur, if transport governance is based on these publications. This is due to the limited scope of these publications. Furthermore, trade-offs are identified, which give guidance to policy-makers about potential key elements in transport governance. This implies that transport governance has to become aware on unintended consequences. The broadened approach chosen in this study has identified the following criteria as important for sustainable transport governance: costs, WTW-energy, infrastructure (transport and energy), land-use, natural resources, social impacts and social acceptance. Unintended consequences have to be politically managed through well-adjusted and context-specific measure combinations, preferably backed up with long-term strategic planning. Modelling results show that the successful management of unintended consequences is possible through re-organizing transportation systems in combination with long-term technology change. Modal shifts (through organizational measures) and transport demand reduction (through behavioural measures) play a key role in reducing CO2 sustainably. Re-organizing transport to more energy-efficient means should get the highest priority, as it has proven to generate the least indirect impacts. The management of intended (CO2 mitigation) and unintended consequences requires significant cross-sectorial policy coordination in the near future to achieve a sustainably “sound” transport system by 2050. This study is considered as a methodologically new approach to include additional criteria for the development of sustainable transportation. The developed optimized scenario “Organization first” should be considered as a valid basis for further discussions on controlling unintended consequences of transport-related CO2 reduction in transport.