• Energy Research

Purpose The dairy sector covers multiple activities related to milk production and treatment for alimentary uses. Different dairy products are available in the markets, with yoghurt being the second most important in terms of production. The goal of this study was to analyse from a cradle-to-grave approach the environmental impacts and energy balance derived from the yoghurt (solid, stirred and drinking yoghurts) manufacture process in a specific dairy factory processing 100 % Portuguese raw milk.

Abstract The market for insulation material is playing a crucial role in Europe's energy transformation, due to its influence on energy consumption in buildings. The introduction of renewable materials for thermal insulation is recent, and little is known so far about its environmental implications. This study analyses the environmental performance of a cork insulation board, made of agglomerated cork from forestry cork wastes, by means of cradle-to-gate Life Cycle Assessment methodology. The results indicate that the use of natural insulation materials does not necessarily imply a reduction of environmental impacts due to manufacturing processes with a low technological development. In this case, the most influential stage is the manufacturing stage, in which the board agglomeration and the cork trituration have the highest impacts. The most influential inputs are both the transport used during the life cycle and the large quantities of electricity and diesel in the manufacturing stage. Some strategies have been identified to reduce the environmental impact, such as promote the acquisition of local raw cork to reduce transportation from the manufacturer, improve the efficiency and productivity of manufacturing processes and improve the product design to help increase its market share. Moreover, the inclusion of biogenic carbon contained in forest-based building materials affects the Global Warming Potential results considerably. However, it is very important to consider how this biogenic carbon is calculated and how the product is managed after its lifetime.

This article analyzes different forest management strategies to meet the increasing demand of biomass for bioenergy and assesses the resulting global warming implications. Applied to maritime pine forest plantations in Portugal, the assessed strategies are: full harvest of residues (FULL); sustainable and proactive management (SMART); expansion of forest plantations on abandoned farmland (EXP); and biomass import (IMP). A dynamic CO2 inventory was obtained for each scenario using a parametric stand-level C-flux model adapted to Portuguese conditions, which was then extended to the landscape-level and coupled to a dynamic climate model. The time-adjusted absolute global warming potential (AGWP) was then calculated at both stand and landscape levels, considering the timing of all CO2 emissions and uptakes (both fossil and biogenic). To test the robustness of the findings, a sensitivity analysis was performed. Results show that, in a supply-constrained context like Portugal, SMART and EXP management strategies can provide important global warming mitigation benefits (GWPbio < 0), although their supply-response is slow (long-term strategies). On the other hand, FULL and IMP management strategies show moderate to null AGWP reduction potential (0 < GWPbio < 1), while involving other possible risks (e.g., exacerbated soil erosion, nutrient depletion or uncertain impacts abroad), but their supply-response is fast (short-term strategies). National forest regulations and energy policies should be revised to address the drawbacks related to all management strategies and to unleash the multiple environmental benefits they can provide in the short- and long-term.

Abstract Four types of commercially-available domestic hot water (DHW) systems (natural gas instantaneous, electric instantaneous, electric storage and heat pump) were analysed and compared from a life cycle assessment (LCA) perspective and their environmental hotspots (stages and processes) were determined. In addition, the influence of the origin of the energy consumed during their usage was analysed and their environmental performance was compared with that of new DHW systems recently developed. A cradle-to-grave analysis was adopted by employing data provided by the manufacturer and supplemented with secondary data from Ecoinvent. The ReCiPe 2016 (hierarchist perspective) method was used to perform the impact assessment. Regardless of the type of water heater, the use stage (due to high energy consumption) was clearly the main responsible for the environmental damage by DHW systems, but the stage of production of raw materials was also important. A comparative analysis of the four current water heating systems showed that the heat pump caused the least impacts (by litre of heated water provided per year), followed by gas-fired, electric storage, and electric instantaneous in that order. The environmental burdens are highly influenced by the country in which the DHW systems are installed because the origin of the energy source used varies. New water heaters developed by manufacturer demonstrated a trend to an environmental improvement compared to the current ones, although improvements with respect to materials consumed are still required.

How relevant is the role of CO2 from harvested wood products (HWPs) for the Brazilian GHG emission balance? The C stocks and CO2 emissions and removals from the HWPs in Brazil during 1900–2016 were evaluated using three methodological approaches: stock-change approach (SCA), production approach (PA), and stock-change of domestic origin (SCDOA). Data from the FAO’s FAOSTAT system on production, import and export of semi-finished products (sawnwood, wood-based panels and paper/paperboard) were analyzed, considering distinct land-use activities: deforestation (D), forest management (FM) and afforestation/reforestation (A/R). Two scenarios to evaluate the effect of HWPs from D were evaluated. The C stock in HWPs in 2016 reached 252 Mt C, by SCA. Contributions to C storage historically were higher from sawnwood, but wood-based panels and paper/paperboard have recently outperformed it. A/R is the major activity responsible for C storage in HWPs. The CO2 removal by HWPs was 521 Mt during 1990–2016, which corresponds to 1.1% of the country’s emissions in the same period. It was concluded that Brazil has become a major producer and wood consumer and that HWPs are allies for a positive C balance and fulfillment of the commitments assumed by the country regarding climate change. Abbreviations AFOLUAgriculture, forestry and other land uses A/RAfforestation/reforestation DDeforestation FAOUnited Nations Food and Agriculture Organization FMForest management HWPsHarvested wood products IBGEBrazilian Institute of Geography and Statistics PAProduction approach PEVSPlant extraction and forestry SCAStock-change approach SCDOAStock-change of domestic origin approach

The measurement of water consumption by trees is fundamental for detecting potential opportunities to mitigate water resource depletion. The water footprint (WF) is a tool to address the environmental effects related to water use, identifying ways to reduce overall water consumption. This work presents a review, updating the information on how WF is being addressed when applied to forest and orchard trees, identifying the methodological trends of the WF studies, and highlighting the main challenges that deserve further research for a consistent WF assessment of these trees. A sample with 43 publications selected based on keyword screening criteria was comprehensively reviewed, showing that most of the studies focus on orchard trees (mainly olive and citrus trees). The bulk of the studies only presented accounting or inventory results (i.e., water volumes consumed) and disregarded their sustainability or impact. This review highlights that a robust WF assessment of forest and orchard trees requires further research for harmonising the quantification of the green water scarcity footprint, and puts key challenges to the WF practitioners, such as the selection of the most adequate method to estimate ET considering trees specificities and climatic parameters, and the adoption of high spatial and temporal resolution for the WF assessment.

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.

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.