Review of the measurement of external costs of transportation in theory and practice : Report 1: maritime transport

In the last years public concerns regarding the environmental impacts of maritime transport have been increasing. This is due to the fact that, despite the better environmental performance of this mode of transport with respect to other modes, its overall impacts will be out weighted by the expected increase in the volume of ship movements. In order to define effective measures to internalise the external costs of maritime transport it is necessary to assess these costs and find adequate methodologies to evaluate them. Besides external costs estimation, it is important to understand the degree of internalization of such costs, so as to give some insights on how to apply policy instruments that should be informed by efficiency and equity principles. This report summarises the state of the art in evaluation of transport externalities. Different transport modes have been considered through a comprehensive review of theoretical and empirical studies, by carrying out both EU funded research and national studies. the analytical approach adopted to assess environmental costs (with particular reference to those relating to air emissions) in order to be applicable to maritime transport have to be adjusted to consider the following aspects. 1. The existing literature on climate change external costs focus on shadow price of CO2. However, in maritime transport other GHGs, such as NOx, are relevant. As a consequence, a shadow price for NOx needs to be defined; 2.Health effects of ship emissions depend on exposure to pollutants. Of course this occurs only for activities at ports, whilst health effects of other activities (like cruising) could turn to be negligible to the absence of exposure. Dose response function should consider this aspect.