A new White Paper (download below) from CirculaTUM, TUM’s interdisciplinary mission network for circular economy research, examines current approaches to measuring vehicle greenhouse gas emissions. Written by a multidisciplinary team led by TUM School of Management faculty members Prof. Johannes Fottner, Prof. Magnus Fröhling, and Prof. Tim Büthe, the White Paper takes stock of current research on car emissions across the entire vehicle life cycle, from production and operation to recycling and end-of-life treatment. It combines these findings from science and engineering research with regulatory and political economy analyses to identify a pathway to a broader, life cycle-based regulatory approach in automotive climate regulation that would incentivize more emission-reducing innovations to boost economic growth as well as climate change mitigation.
Looking Beyond the Tailpipe
At the center of the White Paper is a simple question: Does measuring emissions at the tailpipe capture a vehicle’s full climate footprint? The researchers argue that it does not.
Regulation (EU) 2019/631, which governs CO₂ emissions for new passenger cars, primarily evaluates vehicles based on tailpipe emissions. As a result, emissions released during vehicle production, through the electricity used to operate the vehicle, and at the end of a vehicle’s life remain largely outside the regulation’s compliance metric.
The researchers argue that this creates a disconnect between how emissions are measured and where they actually occur across a vehicle’s life cycle.
What the Analysis Shows
The White Paper finds that battery-electric vehicles reduce life-cycle emissions by an average of 41 percent compared with combustion-engine vehicles. This average reflects the combined evidence from 19 studies and 47 modeled scenarios, and the results depend on factors such as production conditions, the sustainability of the electricity used, and end-of-life treatment. Approximately 92 percent of the analyzed scenarios show lower life-cycle emissions for battery-electric vehicles.
At the same time, the results reveal substantial variation, including among battery-electric vehicles. The current version of Regulation (EU) 2019/631 makes these differences invisible and thus provides no incentives for further progress and innovation.
According to the researchers, these differences are largely invisible in a tailpipe-only metric, which captures emissions at a single point while overlooking contributions elsewhere in the vehicle life cycle. While battery-electric vehicles are treated as zero-emission vehicles for compliance purposes under Regulation (EU) 2019/631, the study highlights the role of emissions generated elsewhere in the value chain.
Supply Chains and Circularity Matter
The White Paper highlights additional opportunities for reducing emissions beyond vehicle operation itself. Investments in low-carbon steel, lower-emission battery production, renewable energy sources, and circular economy solutions can all influence a vehicle’s overall climate footprint.
From a logistics perspective, Prof. Johannes Fottner points to developments that are already taking place across the automotive sector:
“There is already real progress today in building traceable supply chains for green steel and in recovering materials at the end of a vehicle’s life – progress that current regulation simply fails to capture. Regulation that does not recognize this gives industry no incentive to realize this potential, even though it is already prepared to do so.”
According to the researchers, a framework that does not account for these contributions cannot reward them, potentially limiting incentives for their wider adoption.
What This Means for Future Climate Targets
Beyond accounting questions, the White Paper examines the potential implications for future climate targets. The achievements of these targets is in question (see, e.g., Tang et al. (2023). Additional measures are needed to reach these aims.
In this context, the White Paper aims to support discussions on the ongoing revision of Regulation (EU) 2019/631 towards a comprehensive and differentiated policy that incentivizes efforts towards reaching these aims. According to the authors, the current proposal’s steel and fuel credits address only part of the challenge and do not fully account for emissions throughout the vehicle's life cycle.
A Life-Cycle-Based Standard for Defossilization
Building on these findings, the researchers propose a life-cycle-based standard for defossilization that would recognize verifiable emissions reductions wherever they occur across a vehicle’s life cycle, rather than focusing exclusively on tailpipe emissions.
Prof. Magnus Fröhling emphasizes that life-cycle thinking is already established in other areas of European regulation:
“European precedents already exist in the Ecodesign Regulation and the Carbon Border Adjustment Mechanism. What matters is that a new standard be built on performance-based crediting that treats every ton of fossil carbon actually saved equally – regardless of where in the life cycle it is saved – while also being practically operable. Steel already offers the most reliable data basis for this and is therefore the right starting point.”
Sustainability Meets Public Policy
A key contribution of the White Paper is to link a systematic review of the finding about automotive sector CO2 and other greenhouse gas emissions from the scientific literature in engineering, natural sciences and sustainability assessment to an analysis of legal, regulatory and political challenges and possibilities. Made possible by an exceptionally multi-disciplinary team of contributors, the White paper thus seeks to enrich both the regulatory policy debate and public discourse throughout Europe.
Prof. Tim Büthe sees opportunities for progress in the ongoing European debate:
“Scientific experts agree that a life cycle-based approach to measuring automotive CO2 emissions is superior, but this scientific consensus is not yet reflected in EU regulatory practice, which currently is too blunt to create reliable incentives for climate change mitigation. Many car manufacturers and their suppliers are actually ahead and already collect the data and provide life cycle assessments. Some harmonization will be needed, but even the infrastructure to make it happen for the entire sector already there. And even the political conflicts in the EU are not really about whether a vehicle’s life cycle should be captured by regulation, but only about how fast this should occur and whether it should be mandatory. A pragmatic compromise should readily be possible so as to create more effective incentives for greater emission-reducing innovations.”
Taken together, the findings suggest that the potential for substantial emissions reductions across the automotive sector extend well beyond the powertrain alone. By accounting for production, energy provision, and end-of-life treatment alongside vehicle operation, a life-cycle perspective can provide a more comprehensive view of a vehicle’s climate footprint. The White Paper lays out a pathway for how to get there.
Publication
The study is available for download below.
Fottner, J.; Fröhling, M.; Büthe, T.; Ferraresi, F.; Fischer, A.M.; Kigwiru, V.; Schirmeister, J.; Schönherr, C.; Varamishvili, S. (2026). Defossilization, Not Decarbonization: Toward a Life Cycle-Based Standard for Automotive Greenhouse Gas Regulation. White Paper, Technical University of Munich.
The research for the White Paper was funded by the three chairs with supplemental funding by the TUM University Foundation. The authors declare that they have no conflicts of interest.
Defossilization, Not Decarbonization
Toward a Life Cycle-Based Standard for Automotive Greenhouse Gas Regulation
