Automakers under report Scope 3 emissions by 33%, new study finds, and some now look more carbon intensive than oil majors

New research has found that major automakers under report their Scope 3 emissions by 33%, meaning some manufacturers are now estimated to be more carbon intensive than oil and gas firms when a corrected methodology is applied. The study does not name a single outlier but characterises the underestimation as a sector wide pattern among leading car manufacturers. The gap between reported and estimated figures is large enough to fundamentally alter how investors, regulators, and procurement counterparties assess the climate performance of these companies.

Scope 3 emissions in the automotive sector are dominated by the use phase of vehicles sold, which means that what manufacturers report as their carbon footprint is shaped heavily by the assumptions they apply to how customers will drive and charge those vehicles over time. If those assumptions are optimistic, the reported figure will be structurally lower than reality. A 33% underestimation implies that the assumptions being used across the industry are systematically skewed rather than reflecting isolated methodology choices by individual companies.

For ESG managers at companies that supply into the automotive value chain, this finding carries a direct compliance implication. Under ESRS E1, companies must disclose Scope 3 emissions with sufficient granularity to allow investors to assess material climate risk. If the anchor numbers provided by automakers are off by a third, then any supplier relying on customer provided data to calculate its own downstream Scope 3 exposure is inheriting a material error. This is precisely the kind of data quality problem that auditors and assurance providers will escalate as CSRD verification requirements tighten.

The research also sharpens the regulatory case for third party verification of Scope 3 data. The GHG Protocol already permits companies to use a range of methodologies for category 11 (use of sold products) emissions, and the latitude within that framework appears to be a key driver of the discrepancy the study identifies. Regulators considering future ESRS technical guidance will likely point to findings like this when arguing for narrower methodology choices or sector specific factors.

For procurement leads, the immediate action is to scrutinise what baseline emissions data your automotive customers or counterparties are sharing with you, and to flag whether those figures have been independently verified or are based on internal modelling. Automated supplier engagement tools that capture raw activity data rather than pre calculated emissions figures offer a more robust foundation. The gap between what buyers ask for and what suppliers can provide is exactly where platforms like SOMA operate, and findings like this study make the case for closing that gap at the data collection stage rather than at the reporting stage.