Carbon opportunity costs of biofuels in Germany

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In this project, the so-called carbon opportunity costs for biofuels used in Germany were calculated for the first time. According to official data, the greenhouse gas emissions saved by using cultivated biofuels instead of fossil fuels amounted to 9.2 million t CO₂-eq. in 2020. If one were to forego this saving and instead allow natural vegetation to grow on the areas occupied for biofuels, an average annual carbon sequestration of over 16 million t CO₂ would be possible. This is the carbon  opportunity cost of biofuel production, and it is significantly higher than the emission reduction from replacing fossil fuels.

In addition, the study produced as part of the project shows that the mileage currently covered by biofuels from cultivated biomass can be made available for electric drives via solar power on only about 3% of the area. If the switch to e-mobility is combined with a renaturation of the 97% of the land that is freed up, annual emission savings of 27 million t CO₂ are possible. This is almost three times the officially reported total savings in greenhouse gas emissions from biofuels.

Furthermore, renaturation instead of cultivation and use of biofuels would be associated with further ecological benefits: Increasing the share of natural land, protecting biodiversity and ecosystem services, reducing the input of acidifying and eutrophying substances into soil, water and air.