Decarbonizing regional air transport: Strategic pathways for sustainable multi-airport systems in developing economies

As the global aviation sector advances toward net-zero emissions targets, multi-airport systems (MAS) in developing economies confront the dual imperative of accommodating surging air travel demand while aligning infrastructure development with climate commitments. This study examines how MAS can serve as strategic catalysts for decarbonization by analyzing three rapidly urbanizing metropolitan regions in Southeast Asia: Metro Manila (Philippines), Jakarta (Indonesia), and Ho Chi Minh City (Vietnam). Employing a mixed-methods approach that integrates stakeholder interviews (n = 27), policy document analysis, and operational assessments conducted between November 2023 and April 2025, the research applies a sustainability transitions framework informed by multi-level perspective (MLP) theory and strategic spatial planning models to evaluate how emerging MAS navigate the tension between growth imperatives and environmental responsibility. The findings reveal three distinct decarbonization trajectories shaped by governance structures, institutional coordination, and strategic framing. Metro Manila's New Manila International Airport represents a greenfield opportunity to embed renewable energy systems and sustainable aviation fuel (SAF) infrastructure from the design phase, yet faces challenges in cross-jurisdictional climate governance and policy enforcement. Jakarta's multi-airport strategy demonstrates early potential for multimodal integration through high-speed rail connectivity, but remains constrained by institutional fragmentation and limited alignment between airport development and national climate objectives. Ho Chi Minh City's Long Thanh Airport exemplifies a hybrid model that strategically integrates green building certification and intermodal planning while reducing environmental pressures on the urban core, though implementation depends critically on inter-agency coordination and sustained climate finance. Comparative analysis establishes that the success of MAS decarbonization hinges not merely on technological adoption but on the coherent alignment of national climate policy, governance reform, spatial planning frameworks, and infrastructure investment cycles. The study contributes to MAS literature by demonstrating that airports in developing economies function as territorial transformation platforms where sustainability outcomes depend on early-stage embedding of climate objectives, institutional capacity for cross-sectoral coordination, and strategic positioning within broader regional development agendas. Policy implications emphasize that developing economies should proactively integrate decarbonization into airport master planning, establish multi-stakeholder governance mechanisms, leverage international green finance and climate-conditioned investment, and align MAS development with national sustainable development pathways to ensure these systems evolve as low-carbon, resilient regional transport ecosystems rather than replicating carbon-intensive infrastructure models.