Biomass and bioenergy: A systematic and critical review of the global sustainable potential until 2050

Bioenergy plays a pivotal role in global defossilisation strategies, particularly in smart energy system scenarios that rely on bioenergy with carbon capture and sequestration to achieve net-zero and net-negative emissions. Nevertheless, estimates of the global bioenergy potential vary widely across the literature, reflecting divergent methodological assumptions and sustainability constraints. This review synthesises three decades, 1999–2025, of global bioenergy resource assessments, tracing the evolution from early theoretical projections exceeding 138,900–277,800 TWh (500–1000 EJ) to more recent sustainability-constrained estimates. The review examines agro-ecological zoning models, bottom-up resource assessments, integrated assessment models, satellite-derived net primary productivity ceilings, and spatially explicit sustainability-first frameworks. Across approaches, a clear convergence emerges: while technical potentials commonly range between 41,700–111,100 TWh (150–400 EJ), incorporation of sustainability criteria reduces the technical supply envelope to approximately 22,200–41,700 TWh (80–150 EJ) by 2050. This tightening of resource estimates contrasts with several mitigation pathways scenarios in Intergovernmental Panel for Climate Change reports that assume large-scale bioenergy deployment, often exceeding the indicative sustainability limit of 27,800 TWh (100 EJ) by 2050. By linking methodological evolution in resource assessment studies with its representation in global climate mitigation modelling, this review highlights a growing tension between sustainability-constrained supply and mitigation demand. The findings underscore the need for harmonised definitions, transparent land-use accounting, and sustainability-first constraints within integrated assessment models frameworks. Bioenergy can contribute meaningfully to defossilisation of energy systems, but aligning climate pathways with empirically grounded sustainable supply limits is essential for credible and ecologically robust net-zero strategies.