Road traffic and CO₂ emissions
The specific CO2 output and the fuel consumption of new German cars almost remained at a stable level in 2017. The average carbon emissions of cars manufactured by German OEMs rose slightly by 0.7 per cent compared to 2016 and reached 128.1 g CO2 per km. A closer look at the long-term evolution reveals that the current CO2 figure lies 25.4 per cent below the values measured ten years ago. Passenger cars of German manufacturers with a petrol engine nowadays just consume 5.6 liters per 100 km; Diesel cars even consume only 4.9 liters per 100 km. At the end of 2017 the portfolio of the German OEMs includes 1,200 models with specific CO2 emissions below 120 g/km. 220 models emit even below 100 g/km which is equivalent to less than 4 liters per 100 km. This number has almost doubled in the last three years. 111 models with a German corporate logo are already in the class below 95 g/km.
The total emissions of the road traffic in Germany follow a positive trend. After the collapse of the iron curtain in 1990 goods and passenger transport and consequently CO2 emissions have strongly increased. The growth in the 1990s was followed by a decrease of 30 million tons CO2 from 1999 until 2010 according to the national inventory report of the federal environment agency. These days the total emissions linger at the relatively low level of 1991 whereas the transport and traffic volume has expanded significantly since then.
Key to this was mainly the reduction of the specific energy consumption per vehicle. At present 100 passenger kilometres require about 34 mega joule. In 1990 the energy necessary for the same output was 55 mega joule, that is about 50 per cent higher. There are several reasons that despite this high decrease per vehicle the total emissions of the road traffic did not sink considerably at the same time. For many years the road traffic volume has been growing sharply, today it is one fifth higher than in 2000. The clear rise both in passenger and goods transport notwithstanding, the absolute CO2 emissions could be reduced by 9 per cent in the same time period. This shows the substantial efficiency gains of the past years. The challenge of the next years will be to continue on this path. An especially important task will be to enhance the acceptance of alternative power trains to reconcile the human need for mobility and its consequences on the environment.