'Small-scale' tourism versus traditional tourism: Which will be the new key to achieve the desired sustainable tourism?

The tourism sector after COVID-19 has raised different concerns that have lead to a development towards a more sustainable model of tourism. After the health crisis, the increase in environmental awareness of tourists has become evident. In this context, the great paradigm of 'small-scale' tourism has been developed as opposed to traditional tourism. The present work seeks to contribute to sustainable development in the Spanish tourism sector, comparing a hostel in Cantabria (considered as 'small scale' /religious tourism) and a hotel in Lloret de Mar (considered as a traditional tourism) one using the Life Cycle Assessment (LCA) methodology to verify advantages and disadvantages of both types of tourism. The functional unit (FU) used was 'per guest night with breakfast included'. The results have revealed similar results for both establishments in all impact categories, as can be seen in its contribution to Climate Change (4.41 kg CO2 eq./FU caused by the hotel and 4.78 kg CO2 eq./FU by the hostel). The electricity consumption and the impact of the breakfast in the hostel were identified as main contributors to environmental burdens (with 76.72 % of the hotel's impact to climate change and 77.36 % for the hostel); hence, improvement opportunities envisaged were focused on these critical points. On the one hand, a biomass boiler, a solar water-heating system and a hybrid solar/biomass heating are considered a more sustainable alternatives related to electricity. Natural gas and diesel Consumption, respectively. On the other hand, oatmeal, Greek yoghurt and berries are good options for a breakfast with a reduced environmental impact. It is also important to implement responsible and green practices in order to achieve more environmentally sustainable alternative and traditional accommodations. Therefore, it can be concluded by stating that LCA is a tool capable of identifying and studying the processes with the highest environmental impact in order to find out the most sustainable form of tourism.

Life cycle assessment to address the environmental impacts of tourism in a Spanish tourist destination: The case of Rias Baixas (Galicia) holidays.

Tourism has grown steadily in recent decades, becoming a strategic sector for the economy in many countries. However, the environmental impacts associated with tourism have also experienced an upward trend. In this sense, innovation is needed in the tourism sector, to move towards new models and strategies that integrate environmental sustainability with the social aspects of the sector. In this study, a holistic assessment of the environmental impact of tourism has been carried out using the Life Cycle Assessment (LCA) method, considering all stages of tourism activity: transportation from the place of origin to destination and back, accommodation, catering, and activities conducted. For this purpose, a case study has been carried out based on a typical trip made from Madrid to Rías Baixas (Galicia), considering a four-night stay and the performance of two activities (music festival and cultural museum) at the destination. Two alternative transportation scenarios (train or plane) have been defined to analyze the influence of the type of transportation on the overall impact. Other touristic activities such as visiting gardens or thermal baths instead of visiting a cultural museum or attending a music festival have been analyzed and it has been found that the thermal baths and the museum have the greatest environmental impacts. Transportation was the biggest contributor to most of the environmental impacts in the selected categories. On the other hand, the stay at the destination has stood out due to the impact of the consumption of food and energy used at the accommodation facility. The impact of the activities conducted at the destination is also worth highlighting. Finally, alternative scenarios for transportation have shown that the mode of transportation selected is key for lowering the overall environmental impact of the stay at the destination, highlighting the public transportation alternative, such as the train, as the most environmentally friendly option.

Comparative Social Life Cycle Assessment of Two Biomass-to-Electricity Systems.

Biomass plays a fundamental role in numerous decarbonisation strategies that seek to mitigate the short- and long-term effects of climate change. Within this context, decision-makers' choices need to comprehensively consider potential sustainability effects associated with bioenergy systems. In particular, due to the lack of studies addressing the social sustainability of bioelectricity, the present work applies the Social Life Cycle Assessment (S-LCA) methodology to compare the social performance of two biomass-to-electricity systems located in Portugal based on either fluidised-bed or grate furnace technology. S-LCA involves a comprehensive approach for holistic evaluation and data interpretation of social aspects. Six social indicators were benchmarked: child labour, forced labour, gender wage gap, women in the sectoral labour force, health expenditure, and contribution to economic development. The results show that the implementation of fluidised-bed furnaces as a more efficient conversion technology could reduce by 15-19% the selected negative social impacts, except women in the sectoral labour force. When enlarging the interpretation to a sustainability perspective, the general suitability of the fluidised-bed furnace system would be further emphasised under environmental aspects while jointly providing valuable insights for informed decision-making and sustainability reporting.

Life cycle assessment of fish and seafood processed products - A review of methodologies and new challenges.

Life cycle assessment (LCA) has been widely applied in many different sectors, but the marine products and seafood segment have received relatively little attention in the past. In recent decades, global fish production experienced sustained growth and peaked at about 179 million tonnes in 2018. Consequently, increased interest in the environmental implications of fishery products along the supply chain, namely from capture to end of life, was recently experienced by society, industry and policy-makers. This timely review aims to describe the current framework of LCA and its application to the seafood sector that mainly focused on fish extraction and processing, but it also encompassed the remaining stages. An excess of 60 studies conducted over the last decade, along with some additional publications, were comprehensively reviewed; these focused on the main LCA methodological choices, including but not limited to, functional unit, system boundaries allocation methods and environmental indicators. The review identifies key recommendations on the progression of LCA for this increasingly important sustaining seafood sector. Specifically, these recommendations include (i) the need for specific indicators for fish-related activities, (ii) the target species and their geographical origin, (iii) knowledge and technology transfer and, (iv) the application and implementation of key recommendations from LCA research that will improve the accuracy of LCA models in this sector. Furthermore, the review comprises a section addressing previous and current challenges of the seafood sector. Wastewater treatment, ghost fishing or climate change, are also the objects of discussion together with advocating support for the water-energy-food nexus as a valuable tool to minimize environmental negativities and to frame successful synergies.

A comparative life cycle assessment of centralised and decentralised wood pellets production for residential heating.

Recently, wood pellets have become a reliable and clean renewable fuel for residential heating, replacing fossil fuels and reducing greenhouse gas emissions. Wood pellets are normally produced in industrial pellet plants (centralised production), but decentralised small-scale local production also occurs. This study applies Life Cycle Assessment (LCA) to quantify and compare the environmental profile of one centralised and two decentralised alternatives for wood pellet production for residential heating in Portugal: (1) industrial wood pellets production (centralised), (2) wood pellets production at sawmills (decentralised) and (3) wood pellets production at households (decentralised). System boundaries include the stages of forest management, wood pellet production, wood pellet distribution and wood pellet energetic conversion. The impact results show that industrial pellet production ranks as the worst alternative, while pellet production at households has the best environmental profile for all the impact categories under study. However, the environmental impacts of pellet production at the sawmill do not differ greatly from those of the pellet production at households; they are 14 to 16% higher for global warming and fossil resources scarcity and 0.3 to 3% higher for the remaining impact categories. The worst environmental performance of the industrial pellet production alternative is mainly due to high electricity and diesel consumption during wood pellet production and the use of logging residues to generate heat for drying biomass feedstock. A sensitivity analysis was performed to evaluate the influence of changing the distance travelled during the transport of packed pellets to stores and sawdust to households. The results show changes in the environmental performance ranking, highlighting that for short distances, both decentralised alternatives can be more sustainable from an environmental perspective than the centralised alternative, but for larger distances, the pellet production at households should be avoided.

Life cycle assessment of woody biomass ash for soil amelioration.

The increasing use of forest biomass as a fuel for power plants due to environmental concerns will certainly increase the amount of woody biomass ash produced. Because of the environmental problems derived from woody biomass ash disposal, an important aspect for the sustainable development of the energy sector is the implementation of effective ash management strategies. The purpose of this study is to assess the environmental impacts of woody biomass ash landfarming for soil amelioration through a Life Cycle Assessment. The baseline scenario corresponds to the current most common practice of woody biomass ash management (landfilling), and two different landfarming alternatives were assessed: liming and fertilisation. Credits were given to the system due to the substitution of three traditional liming products and five traditional fertilisers. Woody biomass ash landfarming presented satisfactory performance in five impact categories under study in comparison to landfilling. When woody biomass ash was used for liming, the environmental savings were more pronounced when substituting hydrated lime. For potassium supply, the substitution of potassium nitrate by woody biomass ash presented the best environmental performance, while for phosphorus supply, the environmental savings were more pronounced substituting single superphosphate. However, in four impact categories, the environmental impacts of ash landfarming exceeded the impacts of ash landfilling, due to the emission to soil of nutrients and trace elements to soil. But this does not necessarily imply increased risks for the environment, as the potential pollutants leaching depends on their bioavailability in the soil.

Defining freshwater as a natural resource: A framework linking water use to the area of protection natural resources.

PURPOSE: While many examples have shown unsustainable use of freshwater resources, existing LCIA methods for water use do not comprehensively address impacts to natural resources for future generations. This framework aims to (1) define freshwater resource as an item to protect within the Area of Protection (AoP) natural resources, (2) identify relevant impact pathways affecting freshwater resources, and (3) outline methodological choices for impact characterization model development. METHOD: Considering the current scope of the AoP natural resources, the complex nature of freshwater resources and its important dimensions to safeguard safe future supply, a definition of freshwater resource is proposed, including water quality aspects. In order to clearly define what is to be protected, the freshwater resource is put in perspective through the lens of the three main safeguard subjects defined by Dewulf et al. (2015). In addition, an extensive literature review identifies a wide range of possible impact pathways to freshwater resources, establishing the link between different inventory elementary flows (water consumption, emissions and land use) and their potential to cause long-term freshwater depletion or degradation. RESULTS AND DISCUSSION: Freshwater as a resource has a particular status in LCA resource assessment. First, it exists in the form of three types of resources: flow, fund, or stock. Then, in addition to being a resource for human economic activities (e.g. hydropower), it is above all a non-substitutable support for life that can be affected by both consumption (source function) and pollution (sink function). Therefore, both types of elementary flows (water consumption and emissions) should be linked to a damage indicator for freshwater as a resource. Land use is also identified as a potential stressor to freshwater resources by altering runoff, infiltration and erosion processes as well as evapotranspiration. It is suggested to use the concept of recovery period to operationalize this framework: when the recovery period lasts longer than a given period of time, impacts are considered to be irreversible and fall into the concern of freshwater resources protection (i.e. affecting future generations), while short-term impacts effect the AoP ecosystem quality and human health directly. It is shown that it is relevant to include this concept in the impact assessment stage in order to discriminate the long-term from the short-term impacts, as some dynamic fate models already do. CONCLUSION: This framework provides a solid basis for the consistent development of future LCIA methods for freshwater resources, thereby capturing the potential long-term impacts that could warn decision makers about potential safe water supply issues in the future.

Life cycle assessment of wood pellets and wood split logs for residential heating.

Wood-fuelled systems are commonly used all over the world for residential heating, and recently wood pellets have been replacing traditional firewood. This article presents an environmental life cycle assessment of five wood-based combustion systems for residential heating: i) a pellet stove using maritime pine pellets; a wood stove using ii) eucalyptus (Eucalyptus globulus Labill.) and iii) maritime pine (Pinus pinaster Ait.) split logs; and a fireplace using iv) eucalyptus and v) maritime pine split logs. The functional unit is 1 MJ of thermal energy for residential heating. System boundaries include four stages: (1) forest management; (2) pellet and wood split log production; (3) distribution; and (4) thermal energy generation. Environmental impacts were calculated for seven impact categories from the ReCiPe 2016 midpoint method, and a sensitivity analysis was performed using the Product Environmental Footprint (PEF) life cycle impact assessment method and modifying the distances travelled. Of the five heating systems analysed, the fireplace presents the worst performance for all the impact categories with the exception of freshwater eutrophication and marine eutrophication, when maritime pine split logs are burned in the fireplace. Comparing the pellet stove with the wood stove, neither system is better for all the impact categories analysed. Regarding sensitivity analysis, the use of an alternative characterisation method leads to similar trends in the results in comparison with those obtained from the ReCiPe method, while changes in transport distances do not affect the total impacts to a large extent.