Inventory and Evaluation of Environmental Performance Indices for Shipping
Increased demand for environmental, energy and sustainability information on products in a life cycle perspective has led to the development of a large number of different voluntary initiatives aimed at communicating the environmental performance of sea transport, such as databases, indices, labels and certificates. There is however a lack of scientific studies that applies the research area of environmental indices to shipping. The majority of previous studies on environmental indices for shipping have focused on comparing indices or to find successful parameters for developing a new index. This study has conducted an inventory of environmental initiatives applicable for communicating environmental performance of ships and shipowners. It has then identified and evaluated voluntary initiatives that are based on an indexing system; defined as ‘environmental performance indices’. The evaluation was conducted on three indices based on principal aspects and criteria found in literature.
The results of the inventory showed a large diversity of 38 environmental performance initiatives related to a diversity of stakeholders. They had different scope, target groups and applications. Most existing initiatives are based on a set of environmental requirements or standards, where specific installed equipment, operational measures, management aspects or compliance with environmental legislation are rewarded in one way or another. Such rewards could be score points or for example reduced port dues. Some initiatives were however based on environmental performance data such as specific emission levels. Many further focused on air emissions and energy efficiency or carbon dioxide emissions. Ten initiatives were identified as environmental performance indices, though their inclusion within this definition was later discussed in further analysis.
The following three indices were evaluated: (1) the Energy Efficiency Operational Indicator developed by the International Maritime Organization, (2) the Performance Metrics Tool developed by Clean Cargo Working Group, and (3) the Clean Shipping Index developed by the Clean Shipping Project. The indices each assess environmental performance based on data for individual vessels, which then is aggregated into a final index. The last two indices use scoring systems for different environmental areas and include performance requirements. These indices could be used for a shipowner to benchmark and market environmental performance of their ships, and for a transport buyer to select the ships and shipowners according to their performance results. Third-party verification exists for all three indices, which provides quality control of the data used for the performance assessment.
It was concluded that the three indices have many similarities, though they show a large variation in their construction and application. The varieties of the three indices could be explained by the variety of stakeholders connected to them. It was concluded that the properties of a particular index depend on the indented use, which in turn depends on the intended users and the developer of the index. It was further concluded that the variety of different initiatives is problematic and shows a need for global standardized methods. The study could contribute to bring order to the variety of concepts of the different initiatives associated with environmental ship indices. It could also identify potential uses and users of the indices. In addition, it could be one way of solving methodological problems of comparison between different indices identified in earlier studies.