Urban transport assessment of emissions and resource demand of climate protection scenarios

Under the German Climate Action Plan, greenhouse gas emissions are to be reduced by 40–42% until 2030 as a mid-term goal for the transport sector. Furthermore, the European Union has set requirements to reduce emissions of air pollutants like nitrous oxides and particulate matter by up to 65% until 2030. Even though there are different mobility strategies, there is no clear solution on how transport systems need to be adapted in terms of utilized means of transport and mobility behavior to meet the requirements set for 2030. Thus, the aim of this paper is to derive mobility scenarios for traffic systems in urban areas, in which the targets set by the German Federal Government and the European Union for the reduction of greenhouse gases and pollutant emissions are met. Therefore, data on the population's mobility behavior as well as emissions and resource use of the means of transport using the example of Hamburg, Germany are collected. Three scenarios are subsequently derived for the year 2030. Each scenario places a different emphasis on the following aspects: expansion of electric mobility, improvement of specific emission factors and mobility behavior, especially regarding the use of cars, public transport, and bicycles. The first scenario shows that it is possible to reduce traffic-related emissions according to the targets without significant behavioral changes, but by increasing the share of electric cars and plug-in hybrid vehicles to over 30% each. Similarly, a shift of 46% of passenger car traffic to public transport and doubling bicycle traffic will ensure that the emission targets are met in the third scenario. The second scenario achieves this with a more moderate combination of the other scenarios' boundary conditions. However, such a strong expansion of electric mobility increases the demand for critical resources such as cobalt, neodymium and dysprosium used in electric vehicles by a factor of 62–72 compared to 2019. The shift of car traffic to public transport and cycling in conjunction with the use of alternative propulsion systems limits the increase in the demand for critical resources to a factor of 20–23 while at the same utilizing the potentials for reducing pollutant emissions.