The Broader Sustainability Aspects of Biobased Aviation Fuels: An Investigation into Socioeconomic and Environmental Impacts

Abstract

As the global aviation industry strives toward net-zero carbon emissions by 2050, sustainable aviation fuels (SAFs) derived from biobased feedstocks have emerged as a crucial pathway to decarbonization. While much of the existing research on SAFs has focused on environmental and technological aspects, limited attention has been paid to their broader sustainability dimensions, such as socioeconomic and human health impacts and supply-demand dynamics. This thesis addresses these gaps by providing an integrated assessment of the sustainability performance of biobased SAF production and supply chains, combining quantitative modelling with a holistic systems perspective.
The research first establishes that biobased SAF constitutes an emerging, complex sector that interacts with multiple industries and societal stakeholders. Given its developmental stage, assessing its full sustainability performance early on is vital for guiding policy and investment decisions. The thesis develops and applies methodological approaches to quantitatively evaluate underexplored sustainability dimensions, focusing on socioeconomic effects, life cycle human health impacts, and the balance between SAF supply and demand under future decarbonization scenarios.
The socioeconomic assessment employs a scenario-based Input-Output (IO) analysis, using Brazil’s projected SAF demand toward 2050 as a case study. The analysis demonstrates that biobased SAF production can generate substantial positive socioeconomic benefits, including net gains in employment and GDP. However, these benefits vary by feedstock type and conversion technology, highlighting the need for region-specific policies to optimize socioeconomic outcomes. Modest negative impacts on trade balance and fossil-sector employment are identified, for which proactive mitigation measures—such as retraining programs and labor reallocation—are recommended to ensure a just transition.
To complement the socioeconomic analysis, the thesis explores human health impacts through a comparative evaluation of six life cycle impact assessment (LCIA) methods. The results reveal that biomass conversion processes are the primary contributors to health-related impacts due to chemical use, energy consumption, and waste generation, followed by feedstock cultivation involving fertilizers and pesticides. The study concludes that no single LCIA method can universally capture human health effects in SAF systems; rather, the methodological choice should be context-specific, guided by study scope and regional conditions.
Further, a supply-demand analysis examines the potential of biobased SAF to meet the aviation sector’s decarbonization targets by 2050. Using European data and multiple scenarios, the findings suggest that sufficient SAF supply is only attainable if feedstock availability exceeds 60% of theoretical potential—an unlikely scenario given competition from other bio-based industries. The results underscore the regional variability in biomass distribution and the importance of aligning national and continental strategies.
Overall, the thesis concludes that biobased SAF holds significant promise in reducing greenhouse gas emissions—up to 75% compared to fossil jet fuel—while promoting socioeconomic development. However, its sustainability performance is highly context-dependent, influenced by technology choice, feedstock type, and policy design. The work advances an operational framework for integrated sustainability assessment that identifies trade-offs and synergies, supporting informed decision-making for SAF deployment. Beyond aviation, the methodological insights contribute to broader discussions on designing fair, effective, and context-sensitive transitions toward a sustainable bioeconomy.