Quantifying the emissions produced along different supply chains is an extremely difficult challenge. However, carbon-based emissions generated by the transport sector have an extremely significant impact on environmental sustainability.To address these issues, we propose a method for estimating the carbon foot-print as an indicator of the environmental sustainability of processes as it represents the total emissions produced within a given process.Therefore, the first problem we come across is developing a tool for calculating the logistic carbon footprint, which clearly defines the boundaries of application of the model and its scope of application. For this reason, the proposed tool will follow a standardized and uniform approach in order to streamline the calculation processes and make it even more efficient: the sources of emissions related to a supply chain are innumerable, so depending on the different approaches to calculating emissions, they can lead to extremely different results. In order to streamline the calculation process, the main sources of primary emissions and indirect emissions due to the supply of fuel oil have been used in a preponderant manner, and then an adjustment factor that takes into account all factors omitted from the model has been introduced. In this way, the calculation of the carbon footprint has been made uniform, homogeneous, and comparable as well as quantitatively reliable.Once themethod of elaboration of the carbon footprint is framed, we will proceed to use this synthetic indicator for the analysis of environmental sustainability for different logistic processes that consider the Port of Trieste as an intermodal exchange hub for intra-Mediterranean traffic and with destination the main markets of continental Europe, taking into account different modes of transport: road, rail, and maritime transport.