La selecció de tècniques i cultius pot determinar l'impacte ambiental i econòmic dels horts en terrat

Investigadors del Institut de Ciència i Tecnologia Ambientals (ICTA) de la UAB, en col·laboració amb el Departament de Ciències Agràries de la Universitat de Bolonya, analitzen els impactes ambientals i els costos econòmics de la producció d'aliments en horts comunitaris en terrat des d'una perspectiva quantitativa. Els resultats aporten noves dades i coneixement sobre la contribució a la sostenibilitat de l'agricultura urbana en el marc del disseny urbà. L'estudi identifica les tècniques, els cultius i les pràctiques més eco-eficients, és a dir, amb un menor impacte ambiental i cost econòmic.La selección de técnicas y cultivos puede determinar el impacto ambiental y económico de los huertos en azoteaResearchers from the Institute of Environmental Sciences and Technology (ICTA) of UAB, in collaboration with the Department of Agricultural Sciences of the University of Bologna, evaluated the environmental impacts and economic costs of community rooftop gardens from a quantitative perspective. The results contribute new data and knowledge about the contribution of urban gardens to sustainability in the framework of urban design and planning. The study identifies the best techniques, crops and practices in eco-efficiency terms, that is, with a lower environmental impact and economic cost

Comparative LCA of recycled and conventional concrete for structural applications

Purpose: Construction and demolition (C&D) waste recycling has been considered to be a valuable option not only for minimising C&D waste streams to landfills but also for mitigating primary mineral resource depletion. However, the potentially higher cement demand due to the larger surface of the coarse recycled aggregates challenges the environmental benefits of recycling concrete. Furthermore, it is unclear how the environmental impacts depend on concrete mixture, cement type, aggregates composition and transport distances. Methods: We therefore analysed the life cycle impacts of 12 recycled concrete (RC) mixtures with two different cement types and compared it with corresponding conventional concretes (CC) for three structural applications. The RC mixtures were selected according to laws, standards and construction practice in Switzerland. We compared the environmental impacts of ready-for-use concrete on the construction site, assuming equal lifetimes for recycled and conventional concrete in a full life cycle assessment. System expansion and substitution are considered to achieve the same functionality for all systems. Results and discussion: The results show clear (∼30%) environmental benefits for all RC options at endpoint level (ecoindicator 99 and ecological scarcity). The difference is mainly due to the avoided burdens associated to reinforcing steel recycling and avoided disposal of C&D waste. Regarding global warming potential (GWP), the results are more balanced and primarily depend on the additional amount of cement needed for RC. Above 22 to 40kg additional cement per cubic metre of concrete, RC exhibits a GWP comparable to CC. Additional transport distances above 15km for the RC options do result in environmental impacts higher than those for CC. Conclusions: In summary, the current market mixtures of recycled concrete in Switzerland show significant environmental benefits compared to conventional concrete and cause similar GWP, if additional cement and transport for RC are limite

Resolving differing stakeholder perceptions of urban rooftop farming in Mediterranean cities : promoting food production as a driver for innovative forms of urban agriculture

Urban agriculture (UA) is spreading within the Global North, largely for food production, ranging from household individual gardens to community gardens that boost neighborhood regeneration. Additionally, UA is also being integrated into buildings, such as Urban Rooftop Farming (URF). Some URF experiences succeed in North America both as private and community initiatives. To date, little attention has been paid to how stakeholders perceive UA and URF in the Mediterranean or to the role of food production in these initiatives. This study examines the promotion and inclusion of new forms of UA through the practice of URF and contributes to the nascent literature on the stakeholder and public perceptions of UA. It seeks to understand how those perceptions shape the development of new urban agriculture practices and projects. Barcelona (Spain) was used as a Mediterranean case study where UA and URF projects are growing in popularity. Through semi-structured interviews with 25 core stakeholders, we show that UA is largely perceived as a social activity rather than a food production initiative, because the planning of urban gardens in Barcelona was traditionally done to achieve leisure and other social goals. However, several stakeholders highlighted the potential to increase urban fertility through URF by occupying currently unused spaces. As a result, the positive valuation of URF depends on the conceptualization of UA as a social or food production activity. In turn, such conceptualization shapes barriers and opportunities for the development of URF. While most UA-related stakeholders (e.g., food co-ops, NGOs) preferred soil-based UA, newer stakeholders (e.g., architects) highlighted the economic, social and environmental opportunities of local and efficient food production through innovative URF

Disseny d'un sistema d'indicadors en camins i diagnosi socioambiental del Camí de Cavalls de Menorca 2008 : sector nord-est

Menorca va ser declarada Reserva de la Biosfera per la UNESCO l'any 1993. Entre d'altres, un dels aspectes més emblemàtics de l'Illa és el Camí de Cavalls. Preservar la diversitat que aquest ofereix comporta una gestió complexa. Per això, és necessària per una millor gestió ambiental la realitzacióNota: Aquest document conté originàriament altre material i/o programari només consultable a la Biblioteca de Ciència i Tecnologia.Nota: Aquest projecte està relacionat amb el titulat "Disseny d'un sistema d'indicadors ambientals en camins i diagnosi socioambiental del Camí de Cavalls: sector sud-oest", redactat per Laura Millet, Ma. Elena Miró, Anna Òdena i Anna Olle

An environmental and economic life cycle assessment of rooftop greenhouse (RTG) implementation in Barcelona, Spain. Assessing new forms of urban agriculture from the greenhouse structure to the final product level

Purpose: rooftop greenhouses (RTGs) are increasing as a new form of urban agriculture. Several environmental, economic, and social benefits have been attributed to the implementation of RTGs. However, the environmental burdens and economic costs of adapting greenhouse structures to the current building legislation were pointed out as a limitation of these systems in the literature. In this sense, this paper aims to analyse the environmental and economic performance of RTGs in Barcelona. - Methods: a real RTG project is here analysed and compared to an industrial greenhouse system (i.e. multi-tunnel), from a life cycle perspective. Life cycle assessment (LCA) and life cycle costing (LCC) methods are followed in the assessment. The analysis is divided into three parts that progressively expand the system boundaries: greenhouse structure (cradle-to-grave), at the production point (cradle-to-farm gate), and at the consumption point (cradle-to-consumer). The applied LCIA methods are the ReCiPe (hierarchical, midpoint) and the cumulative energy demand. A cost-benefit analysis (CBA) approach is considered in the LCC. For the horticultural activity, a crop yield of 25 kg · m−2 is assumed for the RTG reference scenario. However, sensitivity analyses regarding the crop yield are performed during the whole assessment. - Results and discussion: the greenhouse structure of an RTG has an environmental impact between 17 and 75 % higher and an economic cost 2.8 times higher than a multi-tunnel greenhouse. For the reference scenario (yield 25 kg · m¯²), 1 kg of tomato produced in an RTG at the production point has a lower environmental impact (10-19 %) but a higher economic cost (24 %) than in a multi-tunnel system. At the consumption point, environmental savings are up to 42 % for local RTGs tomatoes, which are also 21 % cheaper than conventional tomatoes from multi-tunnel greenhouses in Almeria. However, the sensitivity assessment shows that the crop efficiency is determinant. Low yields can produce impacting and expensive vegetables, although integrated RTGs, which can take advantage from the residual energy from the building, can lead to low impacting and cheap local food products. -Conclusions: RTGs face law limitations that make the greenhouse structure less environmentally friendly and less economically competitive than current industrial greenhouses. However, as horticultural systems and local production systems, RTGs can become an environmentally friendly option to further develop urban agriculture. Besides, attention is paid to the crop yield and, thus, further developments on integrated RTGs and their potential increase in crop yields (i.e. exchange of heat and CO2 with the building) are of great interest

Analysis of the consumer's perception of urban food products from a soilless system in rooftop greenhouses : a case study from the Mediterranean area of Barcelona (Spain)

Unidad de excelencia María de Maeztu MdM-2015-0552Soilless crops are commonly used in rooftop agriculture (RA) because they easily adapt to building constraints. However, acceptance of the produce derived from this system may be controversial. This paper evaluates consumers' acceptance of food from RA in Mediterranean cities, focusing on the quality of the product, production system, and consumers' motivations. We surveyed 238 respondents on the UAB university campus as potential consumers. The survey was distributed via an Internet-link that was provided along with a sample of tomatoes from RA. The results showed that most people approved the quality of RA products and perceived them to be local and fresh (94%). The respondents exhibited acceptance of soilless-produced tomatoes and considered them to be environmentally better than conventionally produced ones (69%). Cluster analysis revealed that consumers with high income levels and a university education had a better perception of the quality and proposed a higher price for RA products, but no difference was found regarding their environmental perception of this products. Moreover, people who possessed more information about the product also had a higher perception of the quality and production system (it was perceived to be environmentally friendly) and would pay more for them. The main concerns of consumers were related to food safety and the social impact of RA. Additional research is needed to improve the sustainability of RA, and the applied measures should be communicated to potential consumers to enhance their acceptance and success

Modelling environmental burdens of indoor-grown vegetables and herbs as affected by red and blue LED lighting

Notwithstanding that indoor farming is claimed to reduce the environmental pressures of food systems, electricity needs are elevated and mainly associated with lighting. To date, however, no studies have quantified the environmental and economic profile of Light Emitting Diodes (LED) lighting in indoor farming systems. The goal of this study is to quantify the effect of varying the red (R) and blue (B) LED spectral components (RB ratios of 0.5, 1, 2, 3 and 4) on the eco-effciency of indoor production of lettuce, chicory, rocket and sweet basil from a life cycle perspective. The functional unit of the assessment was 1 kg of harvested fresh plant edible product, and the International Reference Life Cycle Data System (ILCD) method was employed for impact assessment. Even though most of the materials of the LED lamp and electronic elements were imported from long distances (14,400 km), electricity consumption was the largest contributor to the environmental impacts (with the LED lamps being the main electricity consumers, approximately 70%), apart from the resources use indicator, where the materials of the lamps and the mineral nutrients were also relevant. RB0.5 was the most energy-effcient light treatment but had the lowest eco-effciency scores due to the lower crop yields.This project received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 708672. The elaboration of the manuscript was also supported by a grant from the Fundacion Séneca (reference 20555/IV/18, Call for Fellowships for Guest Researcher Stays at Universities and OPIS of the Region of Murcia) awarded to Francesco Orsini

Life cycle assessment of energy flow and packaging use in food purchasing

The aim of this project is to obtain quantitative data on the metabolic flows (energy consumption, not only by the establishment but also in the transportation of workers and customers, and packaging use) and their resulting environmental impacts of a standard shopping basket purchase in five city center municipal markets and a hypermarket in a suburban retail park in the province of Barcelona (Catalonia, Spain). The main results show that a standard shopping basket purchased in a retail park requires 20 times more energy than one purchased in a municipal market (11.1 kWh and 0.57 kWh, respectively). Customer transportation represents 83.2% of energy consumption in a retail park, while the greatest impacts in a municipal market stem from the establishment itself (49.5%) and worker transportation (40.4%). Secondly, the packaging use inventory is higher in a hypermarket (253 g) than in a municipal market (102 g). However, the overall environmental impact associated with a standard shopping basket is 10 times higher on average in a hypermarket than in a municipal market, and the carbon footprints of the hypermarket and the municipal market are 3.8 and 0.4 kg of CO₂ eq., respectively. According to the sensitivity analysis, current policies for reducing the amount of plastic bag packaging have little repercussion in a retail park because its relative weight in terms of total packaging use is only 7%. Nevertheless, they have notable effects in municipal markets where plastic bags represent 25% of the packaging use. Finally, if customers selected the least packaged products available in hypermarkets, each shopping basket could reduce up to 47.2% of its used packaging weight and between 15.4 and 59.0% of its associated environmental impact

Editors & reviewer's manual for LCADB.sudoe

A la portada: FEDER, SUDOE, Secotech sudoe, Sostenipra, UAB i Inèdit, Universidade de Aveiro, École des Mines d'Alès, +Cemagref, SupAgro, INRA, UdG, Catar agroresoucesThis manual is a guideline for uploading a Life Cycle Inventory (LCI) analysis using the Life Cycle Assessment Data Base tool, which can be found in the following site: http://lcadb. sudoe. ecotech. cat/

Urban agriculture in the framework of sustainable urbanism

Agriculture represents a crucial phase in the development of mankind. Although cities initially had close ties withagriculture, which was a key element in ancient civilisations, in modern twentieth-century urban plans, such as Le Corbusier’s Chandigarh or Lucio Costa’s Brazilia, agriculture was banished from large cities. The demographic growth of urban areas today and its predictions for the short and long term have increased the value of urban agriculture.Peer ReviewedPostprint (published version