The European Parliament has introduced measures to decouple economic growth from CO2 emissions by implementing a progressively increasing CO2 tax. In 2023, the new ISO 14038:2023 standard was adopted with a key aim to significantly enhance the accounting and transparency of greenhouse gas (GHG) emissions, particularly in the operation of port terminals. This standard provides an essential framework for the quantification and reporting of GHG emissions. Through standardized reporting, stakeholders, including regulatory bodies, customers, and local communities, can achieve increased trust and accountability. The ISO 14038:2023 standard is especially relevant for port terminals, where precise control and evaluation of emissions are critical for achieving ecological efficiency. By thoroughly understanding emissions sources, port terminals can optimize resource usage. The enhanced efficiency in technological processes throughout the logistics chain also has the potential to economically impact the reduction of ecological tax burdens. This article focuses on the need for reliable emissions evaluation within port technological processes to assess the ecological efficiency of cargo transshipment using different technologies. It examines the practical application of the ISO 14038:2023 standard in this context, identifying potential challenges and suggesting enhancements to ensure effective implementation at the operator level. By prioritizing the control of CO2 emissions, port terminals can contribute significantly to sustainable development and environmental protection.