Life cycle assessment of green practices for sustainable tourism: glass vs. plastic onboard a cruise ship

The increasing pressure about environmental issues related to tourism sector is nowadays pushing cruise operators towards the investigation of environmentally friendly measures within their activities. In this context, cruise managers should evaluate the inflows and outflows of packaging materials within their purchase activities, in order to reduce waste generation to a minimum, with attention on the entire supply chain and evaluation of alternative methods of waste disposal and waste management systems onboard ships, with investments in new technologies. When focusing on environmental sustainability analysis along the supply chains, Life Cycle Assessment (LCA) methodology plays a strategic role for identifying the critical processes of the so-called life cycle of a product system, and therefore the potential ways for improvement, through the calculation of the environmental burdens in a systematic and scientific way, by regarding all the elementary flows of complex systems. The aim of this paper is to analyze different scenarios for primary packaging management onboard a cruise ship through Life Cycle Assessment (LCA). In particular, the potential environmental impacts due to strategic choices for packaging materials related to water distribution have been evaluated along their life cycle, i.e. from extraction of raw materials to final disposal and/or recycling. The substitution of the total amount of water bottles distributed in the cruise restaurants, shifting from glass to plastic, has been evaluated, in comparison with the reference scenario. Moreover, this study evaluated the possibility of introducing a process onboard in order to treat the polyethylene terephthalate (PET) waste stream deriving from water bottles with a recycling perspective. This measure has been configured as an enhancement of the management scenario where the substitution of water bottles is set up. The results of this study allow concluding that strategic choices for packaging materials and waste materials management are able to yield evident benefits on the environmental balance. The partial substitution of glass bottles with water bottles has been demonstrated to yield not only benefits from waste prevention and minimization point of view, but also in terms of consumption of material and energy resources and potential environmental impacts along the bottles life cycle. In particular, the analysis of Global Warming Potential (GWP) showed that a shift in material supply represents a waste minimization measure that is able to halve the impact on such a crucial indicator for cleaner production and environmental sustainability. Besides, the introduction of a process technology onboard that is able to regranulate PET waste material has been demonstrated to be able to enhance (or not worsen, depending on the impact category) the environmental performance of the system, with the additional benefit of yielding an output flow from the cruise ship that is not a waste but a product, able to enter as a raw material in new life cycles by a recycling perspective.