Balancing multiple sustainability objectives in feedstock cultivation: a case of Pongamia pinnata in Australia

Biofuels are increasingly recognised as a renewable energy source capable of supporting the transition away from conventional petroleum fuels and contributing to emissions reduction targets. At the same time, concerns remain about the potential consequences of using land to produce fuel as opposed to other uses such as food production, carbon storage and ecological conservation. Although these trade-offs have been a concern for decision-makers for some time, existing decision-support tools remain limited in their ability to explicitly assess such trade-offs and inform decisions on where and what feedstock can be cultivated to balance multiple sustainability objectives associated with land-use change. This study presents a novel spatial decision-support framework that integrates ensemble suitability modelling with spatial multi-objective optimisation to identify optimal cultivation zones for land-based low-carbon liquid fuel feedstocks in Australia. Using Pongamia pinnata as a case study, we use multidimensional Pareto frontiers to identify priority areas that maximise feedstock suitability while minimising competition with food production, carbon storage and biodiversity. We find that approximately 30 million hectares would be considered suitable for Pongamia pinnata cultivation based on climatic and environmental factors. Results also show that 17% of this suitable area overlaps with existing agricultural land, primarily in Queensland and New South Wales. Our approach explicitly accounts for sustainability trade-offs, addressing limitations in existing spatial modelling approaches that fail to directly consider competing land-use objectives. Our methodology is adaptable to other regions, feedstocks, and sustainability objectives, and can provide strategic guidance for sustainable land-use planning.