In each study area, Chemical Transport Models have been used to simulate the future development scenarios, as well as the mitigation scenarios, in order to assess the effectiveness of mitigation actions, addressed in strict collaboration with the territorial authorities involved in local working tables.
The future base scenario has been estimated on a reference year (2015 or 2020 or 2025, depending on the city), taking into account both the port development (extension of piers, spatial displacements, increase in port traffic) and the projection of all the other emissions according to future legislation and trend drivers (for example fleet renewal for road transport or change in fuel consumptions).
In particular, future maritime emissions have been calculated considering the reduction to 0.5% for the fuel sulphur content in force as of 2020, according to the Directive 2012/33/EC.
The future base scenario was the basis to calculate the mitigation scenarios that considered specific measures to lowering or mitigating harbour emissions. The difference between the base future and the mitigation scenarios has been calculated both in terms of emissions and concentrations.
The mitigation actions evaluated are in the five cities are:
• Cold ironing for cruise ships or RO-PAX vessels
• 0.1% for sulphur content in fuels to be used also in the manoeuvring phase
• Use of LNG fuel
• Scrubbers to be used to abate emissions during the hotelling or manoeuvring phases
• Displacement of some on shore harbour activities
• Usage of wetting agents (chemical and water) to control the storage pile emissions
As for some outcomes, the PM emissions decrease ranges between 3%, for cold ironing in Marseille, to 78% for the complete vessels fleet renewal with LNG fuel in Barcelona (this action must be considered as the hypothesis of maximum reduction). Relevant PM concentration decreases have been calculated for Barcelona and Genoa in the summer: from 10% to 20% respectively. In the same season, the reduction PM concentrations has been estimated to be less significant for Thessaloniki (1-4%) and Venice (1.5%). In the cold season, the estimated impact of mitigation actions on PM levels is less substantial.
Details on the effectiveness of each measure is available in the publication: " Reducing atmospheric pollution in the Mediterranean Port Cities - The results of APICE project"