Ports, as critical nodes in maritime logistics and supply chains, face growing pressure to decarbonize, yet progress remains slow. While existing research identifies multiple barriers to port decarbonization, limited attention has been paid to how these barriers interact and mutually reinforce one another. This study aims to identify key barriers to port decarbonization and to analyze their interrelationships to uncover the root causes of decarbonization challenges.
Adopting a sociotechnical systems (STS) perspective, the study combines interpretive structural modeling (ISM) and the matrix of cross-impact multiplications applied to classification (MICMAC) approach. Seventeen decarbonization barriers were identified through a literature review and semi-structured interviews with experts from the Portuguese port system. ISM was used to develop a hierarchical model of barrier interactions, while MICMAC classified barriers according to their driving and dependence power.
The findings reveal that barriers to port decarbonization form a highly interconnected system. External environment barriers, which are external challenges coming from outside the ports' organizational boundaries, emerged as dominant root drivers. Examples include global policy gaps and instability, lack of government support and industry complexity. Intermediate challenges related to standards, data availability, funding and knowledge. Those issues function as critical transmission mechanisms between root barriers and highly visible ones. Frequently cited challenges, such as high costs and technological immaturity, appear largely as dependent outcomes rather than primary causes.
This study advances port decarbonization research by moving beyond barrier prioritization toward a multi-level explanation of barrier interactions. By integrating STS theory with ISM-MICMAC analysis, it provides novel insights into where effective intervention points lie in port decarbonization efforts.
