Beyond biomass yield: A conversion-aware framework for climate-resilient feedstocks and sustainable biofuel production

Climate change increasingly threatens biofuel feedstocks through drought, salinity, temperature extremes, flooding and interacting stressors. However, feedstock resilience is commonly assessed from biomass survival or yield, with limited consideration of how stress-induced changes in biomass quality affect downstream conversion and sustainability. This review examines the continuum from climate stress and physiological response to biomass quality, processability and conversion performance, focusing on changes in carbon allocation, structural carbohydrates, lipids, proteins, secondary metabolites, mineral accumulation and biomass recalcitrance. We define conversion-aware resilience as the capacity of a feedstock–conversion system to maintain acceptable biological productivity, biomass processability and conversion performance under climate stress while sustaining favourable environmental and economic outcomes. The framework further recognizes genotype or variety, soil conditions, irrigation regime, nutrient availability and harvest stage as contextual factors that modify stress responses, biomass characteristics and downstream conversion performance. Its assessment is therefore based on measurable indicators including stress-adjusted biomass productivity, water-use efficiency, carbohydrate or lipid accessibility, lignin and ash/mineral content, pretreatment requirements, conversion yield, fuel productivity and associated environmental and techno-economic performance. The review highlights critical resilience-conversion trade-offs, whereby traits that enhance stress tolerance may increase lignification, mineral accumulation or pretreatment requirements, while desirable biochemical enrichment may occur alongside reduced biomass productivity. A conversion-aware climate-resilience framework is proposed linking stress exposure, physiological resilience, biomass quality, processability, conversion compatibility, pathway selection, stress-adjusted fuel productivity and LCA-TEA/resource performance. The framework shifts assessment from feedstocks in isolation toward feedstock–conversion configurations and identifies research priorities including multi-stress factorial experiments, field and multi-location validation, pilot-scale conversion, integrated sustainability assessment and predictive modelling. This approach moves climate-resilient biofuel assessment beyond biomass yield toward measurable conversion-aware resilience and provides a basis for selecting feedstock–conversion configurations capable of maintaining productive and sustainable biofuel systems under future climate conditions.