A System Dynamics Approach to Maritime GHG Emission Reduction: A Case Study on Turkish Bulk Carriers

The shipping industry is under increasing pressure to decarbonize. This pressure, driven by global regulations and the need to mitigate the effects of climate change, provides the impetus for the current study to adopt a system-dynamics approach. The effectiveness of various strategies in lessening greenhouse gas emission within the context of Turkish Bulk Carriers. The model was experimentally calibrated using true ship data from Turkish-flagged bulk carriers that assisted in model development. The model accounts for interactions among regulator-driven factors (Energy Efficiency Existing Ship Index/Carbon Intensity Indicator and carbon pricing), operational approaches (speed and efficiency), fuel prices, dissemination of new technologies, capacity constraints, feedback rules, and delays. Four policy scenarios, simulated through 2050, are: Business-as-Usual (BAU), International Maritime Organization (IMO)-based, Aggressive, and Technological Breakthrough. Annual carbon flow, cumulative carbon dioxide emissions, and changes in the composition of the world's shipping fleet (HFO/liquefied natural gas/Bio/Hydrogen) are included. Model calibration against independent statistics reveals negligible discrepancies between the model and historical data series for various parameters, and sensitivity analysis confirms vessel speed as the main elasticity factor, followed by conventional vessel share and average distance. The analysis provides evidence of an annual weakening of total carbon dioxide emissions in all studied pathways; however, substantial discrepancies remain regarding both timing and magnitude. Recommendations include that comprehensive measures, such as carbon pricing and operational and technological strategies supported by infrastructure investments, can reduce total carbon emissions and long-term costs. In contrast, reliance on isolated, applied technologies may increase cumulative emissions, even while delivering overall benefits.