Exploring the trends of research: a bibliometric analysis of global ship emission estimation practices

Maritime shipping is a crucial part of transportation that carries a significant portion of the global goods traded by volume. A significant amount of emissions is produced by maritime shipping, causing serious health and environmental impacts. By considering this phenomenon of maritime shipping, many scholars have been studying related to ship emissions globally and investigating the consequences and minimization measures of such emissions. It is assumed that many scholarly documents are available with various types of emission estimation, measurement mechanisms, and models to observe and accumulate ship emissions. This study aims to conduct a bibliometric analysis of existing literature on ship emission estimation, measurements, models, and methods. It seeks to review and compare various measures and estimate ship emissions and pollutants. A bibliometric approach was applied to 1709 journal articles relevant to ship emission estimation gathered from two popular databases namely Scopus and Web of Science. The bibliometric analysis revealed a steady increase over time, with a particularly notable growth in the most recent decade. The study identified four main themes: (1) Inventory, Exhaust Emissions, and Impact; (2) Energy, Cost, and Emissions; (3) Technologies, Liquefied Natural Gas, and Emissions; (4) Ships, Emissions, and Impact. The study suggests that there are areas for further research that academic researchers could explore. Additionally, policymakers can use these findings to guide the development of research in this field, adjust policies as needed, and invest in more research to reduce emissions from maritime shipping.