ifeu study: Cars and airplanes are the largest CO2 emitters

The environmental comparison “Environmentally Friendly Mobility!”, a study by the Institute for Energy and Environmental Research Heidelberg gGmbH (ifeu) in cooperation with Infras on behalf of the German Federal Environment Agency, encompasses not only the operation of various modes of transportation but also includes the construction of roads and routes, the production of energy carriers, and the disposal of vehicles. The results indicate how the course for climate- and environmentally-friendly transport policy must be set.

Emissions: Cars and Airplanes are Overall Leaders

According to the new studies, cars and airplanes make up about 95 percent of the total CO2 emissions in passenger transport, as confirmed by ifeu. Public transport, long-distance travel by bus and train, as well as cyclists and pedestrians, account for only 5 percent of climate-relevant emissions—while they cover nearly 20 percent of the distances traveled by people—the so-called traffic performance.

External Environmental and Health Costs

Not surprisingly, cars, motorcycles, and airplanes also perform particularly poorly in terms of external environmental and health costs, according to the report. These include, for example, costs caused by harmful emissions from traffic or costs for adapting to climate change. For international and national flights, according to the study, environmental costs are between 5.2 and 7.8 cents per kilometer traveled per person, while for cars and motorcycles they are between 5.7 and 6.2 cents. Trains in long-distance passenger transport come to 1.4 cents, long-distance buses to 0.8 to 1 cent.

"The external costs of motorized individual transport and flying are particularly severe because over 80 percent of passenger kilometers are covered by these modes of transport," says Wolfram Knörr, project manager for "Ecological Evaluation of Transport Modes" at ifeu.

Environmental Sin Last Mile

According to the study, railways and inland waterways perform particularly well in freight transport. For trucks, the prevailing motto is: the bigger, the better. With payload, dust, NOx, and CO2 emissions per ton-kilometer decrease. For goods exchange between continents, procurement and companies should consistently opt for shipping and, if possible, rail, and particularly avoid transportation by plane.

"Our results show that we need to focus more on small trucks in distribution traffic than we have in the past," analyzes Knörr. These "light commercial vehicles" were almost exclusively diesel vehicles in the reference year 2017. "Especially in cities, the use of cargo bikes and electric trucks is recommended," says Knörr.