ICT investment and carbon emission efficiency in regional port groups: evidence from Chinese coastal provinces

Growing concerns about climate change have intensified scrutiny of port operations as significant contributors to global emissions, prompting ports worldwide to reconcile environmental sustainability with operational efficiency. Yet how digital investments specifically influence environmental performance in regional maritime systems remains insufficiently understood. Existing research has examined ICT’s economic impacts and operational efficiency separately. However, limited empirical attention has been directed towards the relationship between digital transformation and carbon emission efficiency. This gap is particularly notable regarding the differential effects of ICT components and the role of governance structures. This study examines nine Chinese coastal provinces from 2008 to 2019, decomposing ICT capital into hardware, communication equipment, and software components. Using two-way fixed effects models and instrumental variables approaches, we analyse their impacts on carbon emission efficiency within regional port groups. Results indicate that ICT investment significantly enhances carbon emission efficiency, with hardware demonstrating the strongest effect, followed by communication equipment and software. The relationship operates through both direct channels and indirect pathways via functional specialisation. Digital infrastructure enables ports to develop clearer divisions of labour and achieve economies of scale, thereby reducing emissions per unit of throughput. Furthermore, port integration exhibits an inverted U-shaped moderating effect, with optimal integration levels varying across ICT components. These findings advance understanding of environmental returns to digital investment in port infrastructure, offering empirical guidance for policymakers navigating governance challenges in sustainable maritime development.