Skip to main content

09-07-2021 | Emissions | News | Article

Scientists on the Barricades

Marc Ziegler
5:30 min reading time

In open letters to the EU Commission, hundreds of scientists are calling emphatically for a change of course in the implementation of the transport revolution. The tenor: Only free, technology-open competition can bring about rapid and real reductions in Greenhouse Gas emissions. An essay of Marc Ziegler, deputy editor-in-chief of MTZ worldwide.

Germany becomes climate-neutral. Not by 2050 - as is the goal of the entire EU - but by 2045. At least that is the political plan. For some, these plans seem naive because they believe the goal is unattainable, while for others they do not go far enough because 2045 is clearly too late to achieve the Intergovernmental Panel on Climate Change's target of a maximum global warming of 1.5°C. If we continue as we have been doing, we will not be able to achieve this goal and the global residual budget of additionally released fossil Greenhouse Gases will be used up within the next seven years. Reducing emissions can relieve this budget, that much is clear, but is it actually happening?

Editor's recommendation

01-04-2021 | In the Spotlight | Issue 4/2021

Life Cycle Assessments - Controversial, but without Alternative

The decision about the phase-out of fossil fuels in our transport systems has been made and the focus is now primarily on battery electric vehicles, but synthetic fuels and fuel cells are still in the running. Only life cycle assessments that …

This is precisely the issue addressed in an open letter initiated by Prof. Dr.-Ing. Thomas Willner of the Hamburg University of Applied Sciences (HAW) and Dr. Armin Günther of Air Liquide Deutschland GmbH, which was subsequently countersigned by 168 scientists from all over the world. 

And they are not the only ones to take to the barricades: A second open letter to the EU Commission, which has recently been picked up by the mass media in particular, deals with the same issue. It is based on a position paper also signed by 170 scientists who are members of the International Association of Sustainable Drivetrain and Vehicle Technology Research (Iastec).

Calculations contrary to physical facts

The reason for this concentrated effort is the new European fleet limit calculations, in which, for example, BEVs (Battery Electric Vehicles) are to continue to be calculated without CO2 emissions, contrary to the physical facts, but alternative fuels remain completely out of consideration. In addition, alternative fuels are still generally not tax-privileged. And the Renewable Energy Directive (RED) in its 2021 version will not bring about sufficient improvements, according to HAW researcher Thomas Willner, Armin Günther and the co-signers.

Willner highlights three basic demands:

  • No delay: emission reductions must be instantaneous and real, and actions must also be measured by whether they achieve immediate emission reductions.
  • No Greenhouse Gas export: There must be no export of emissions, since in a global context it makes no difference where greenhouse gases are emitted.
  • Fast rollout: Measures must be able to be rolled out quickly and worldwide, since climate protection is a global task and can only succeed through international cooperation.

In an interview with MTZ and, the process engineer elaborates: "You have to calculate things through to the end. A BEV first increases CO2 emissions during production and only achieves an initial reduction in emissions after about five to fifteen years, the batteries are manufactured in the Far East, and the necessary development of infrastructure will still take years." Thus, he said, unilateral subsidies contradict all three requirements. "Free, open-technology competition alone can lead to immediate, real, global reductions," Willner says. 

Energy production in sweet spots

In this context, the scientists see the export and construction of wind power and solar plants in sweet spots such as Africa as indispensable, since there - after the region has become self-sufficient in electricity - the resulting excess capacities can be used to generate CO2-neutral energy carriers, such as hydrogen or synthetic hydrocarbons. These can be distributed as green molecules in the existing infrastructure and used in the existing fleet. The ultimate goal is a clean circular economy. The Fraunhofer Institute for Energy Economics and Energy System Technology IEE has also compiled an overview of the actual potential for the production of green molecules with a Power-to-X (PtX) atlas. In it, the institute shows that in the long term, up to 109,000 TWh of liquid green hydrogen or 87,000 TWh of synthetic fuels could be produced outside Europe.

Structurally weak regions, but also countries that currently have large deposits of fossil fuels, should be promoted internationally. This would create incentives not to resort to cheap fossil energy. In this way, no, or at least less, further fossil CO2 would be emitted, as oil, gas and coal would remain in the earth. 

More CO2 emissions due to possible German ban on internal combustion engines

The scientist is also critical of a ban on internal combustion engines. "If we ban engines in Germany, it actually only leads to fossil fuel becoming a bit cheaper worldwide. In the end, that tends to have the opposite effect, namely more CO2 is emitted elsewhere." In a technology-open approach, on the other hand, the use of waste streams would make sense. Plastics or used fats can be cracked with little energy input and thus serve as a source of carbon, which can then be synthesized into diesel or other fuels very cheaply with little hydrogen. An experimental plant is under construction at HAW Hamburg and is scheduled to begin operation before the end of 2021, when it will produce fuel from waste.

Also in the Iastec letter to the EU Commission, the six scientists from Italy, Spain, Greece, Sweden, Poland and Germany, on behalf of the 170 position paper signatories, call for the planned legislation to be "recalibrated on behalf of all EU citizens who expect effective CO2 reduction." While the average range of total energy expended in a directly-charged BEV is two to three times higher compared to a hybrid vehicle using synthetic fuels, on the other hand, the output of photovoltaic and wind power in many regions of the world is two to three times higher than in Europe, he said. And, "energy storage issues are being solved in parallel along the reFuels path." The Iastec scientists led by Prof. Dr. Thomas Koch of the Karlsruhe Institute of Technology (KIT) further write, "We would therefore like to note that the lowest CO2 powertrain of a small car, especially a diesel hybrid, seems to be completely banned politically and economically, although the CO2 reduction potential of a combined diesel hybrid with R33 fuel in 2030 is circa 50%, which is completely impossible for many countries with a BEV strategy." Koch and his co-signers urge, "We need all technical solutions including an improved BEV strategy. But the only chance to enable automobile-based mobility for all regions in Europe in combination with intensive CO2 reduction is to intensively increase reFuels production." Other regions of the world such as China, Korea, Japan and the U.S. would also recommend an intensive reFuels strategy.


No matter how you slice it, you can really only agree with the scientists. Emission reductions must be immediate, universal and sustainable to be successful. The current method of accounting for emissions using emission factors does not meet these criteria. In the long term, further change can certainly take place, but solutions must prove themselves in all aspects in order to be sustainable. The development of international environmentally friendly infrastructure is not only environmentally friendly, but also socially beneficial, since it is economic and development aid in one. It is also unlikely that there will be any arguments against fuels made from biological waste or plastic waste, as these also solve several problems at once. Excluding modern combustion engines and synthetic fuels from subsidies is definitely the wrong way to go. On the one hand, they can and will be climate-neutral, and on the other, they are simply without alternative in many application scenarios, not only in transport but in all sectors.

Related topics

Background information for this content

01-04-2021 | In the Spotlight | Issue 4/2021

Life Cycle Assessments - Controversial, but without Alternative

01-04-2021 | Cover Story | Issue 5-6/2021

"It makes no sense to use e-fuels only in aircraft or ships"

Supplementary Content

Premium Partner

    Image Credits