Towards life cycle sustainability assessent of cities. A review of background knowledge

Influences of Land Policy on Urban Ecological Corridors Governance: A Case Study from Shanghai

The analysis of land use change (LUC) characteristics and the impact of policies related to urban ecological space is required to improve spatial planning and to support decision making regarding green infrastructure (GI) investment. This study employed Geo-informatic Tupu analysis and Fluctuation Potential Tupu analysis methods to analyze the characteristics of LUC in an urban ecological corridor (EC). To help understand the influence of land use policy on GI governance and support the optimization of spatial planning, we proposed a situation-structure-implementation-outcome (SSIO) policy cascade analysis framework. SSIO takes "place" as its starting point, then couples the local policy with the governance structure to promote the sustainability of urban commons governance. The results show that the land use type within an EC in the city is mainly cultivated land. However, between 2009 and 2019, cultivated land, construction land, and facility agricultural land all showed a decreasing trend, while forest land and garden land types underwent increasing trends. The LUC Tupu unit highlights the transition from cultivated land to forest land. Forest land has the greatest increase in area and accounts for 52.34% of the area of increasing land use. Cultivated land shows the greatest decrease in area and accounts for 70.30% of the area of decreasing trends. Based on the local policy situation of the metropolis, a land policy governance mechanism can be constructed by the establishment of a governance structure with local government as the core, using land consolidation as the platform, taking ecological spatial planning and inefficient construction land reduction as typical policy tools, and experimentally integrating the concept of Nature-based Solutions (NbS). In general, these findings may be applicable to other rapidly urbanizing cities around the world that are developing complex land use policies for ecological space governance.

A holistic environmental and economic design optimization of low carbon buildings considering climate change and confounding factors

The low carbon building design has become critical given the urgent need to reduce global carbon emissions. Reducing operational energy use through multi-objective optimizations used to be a common approach, but its validity is impaired by surging embodied impacts. Therefore, a life cycle optimization becomes necessary to improve the overall carbon performance of buildings. However, current research lacks an application of multi-objective optimizations to explore the energy use, carbon emission and cost considering both embodied and operational impacts. Impacts of confounding design factors and climate change on achieving low carbon designs are also not sufficiently revealed by existing studies. To address these gaps, this study: (i) proposes a parametric design optimization method for low carbon buildings considering cost-effectiveness, (ii) explores the impacts of confounding factors on achieving low carbon designs and (iii) evaluates the impact of climate change on the life cycle performance of buildings with proper scenario assumptions. A case study is conducted to explore passive design parameters and integrated photovoltaic (PV) applications to reduce the energy use and carbon emissions in a cost-effective approach. The joint optimization of embodied and operational impacts can reduce the energy use, carbon emission and cost by 42%, 58% and 32%, respectively. Also, variation of confounding factors can lead to different optimized designs with carbon reduction difference up to 75%. The results also show that global warming will lead to higher energy use and carbon emissions in tropical regions within the near future, while stringent mitigation strategies aligned with RCP 2.6 can reverse the trend after two decades.

Public Bus Transportation System Environmental Impact Projections Regarding Different Policy Scenarios—A LCA Study

Urban activities, such as transportation, are responsible for a large portion of energy-related CO2 emissions. As the need for sustainable urban development increases, decision-makers embrace Life Cycle Assessment (LCA) as a reliable tool capable of generating scientifically based information on environmental impacts. However, there is still a lack of an analysis standard regarding the particularities of urban systems. Therefore, this research aims to define current and future environmental profiles, considering a case study of the public transport system in Porto Alegre, considering specificities of the urban context and different public policy scenarios through LCA. These results show that, although the transportation system management relies on the municipalities, the higher significance of environmental impacts depend on a national policy for using biodiesel in the diesel sold, which could lead to an increase of, for example, up to 9.4% of CO2 emissions from 2017 (baseline) to 2030. Finally, it is perceivable that to conduct a LCA to support decision-making in public urban services, a detailed approach is needed considering that technological variables interact with the territorial context and policy changes.

Sustainability in the Opera Sector: Main Drivers and Limitations to Improve the Environmental Performance of Scenography

Private and public organizations are becoming increasingly involved in achieving the Sustainable Development Goals. This includes organizations within the cultural sector, with a central role in the progress of society. This study presents a state-of-the-art analysis of actions towards sustainability of the opera sector with a life cycle perspective and focusing on the impact of opera sets’ scenery. Our research is based on a review of literature and experiences, the results of interviews, a survey, and an experts’ forum to analyze the related systems, standards, and practices. The study contributes with novel research that provides an understanding of the factors that determine the environmental performance which are synthesized with a sustainability SWOT analysis. Findings are relevant for academic researchers analyzing the potential conflicts among organizational strategic goals and sustainability and for scenic arts’ practitioners and managers who aim to develop a roadmap towards improving the sustainability of their sector.

Linking the Development of Building Sustainability Assessment Tools with the Concept Evolution of Sustainable Buildings

With the rapid development of materials science and construction technology, the concept of sustainable building (SB) and the Building Sustainability Assessment Tool (BSAT) have also evolved and developed. Understanding the development of BSAT and SB is of great significance to the sustainable development of the construction industry. This research used the bibliometric method to analyze the development and evolution in the relevant literature on SB and BSAT from 1990 to 2021, and the correlations and differences between them were investigated. We found that there are many common trends in the development of research efforts in SB and BSAT: (1) they focused solely on the environment, in the early days, and only later considered economic and social impacts; (2) the scales with which they are concerned continue to expand, from individual buildings to communities and even cities; (3) key areas, such as energy, materials, resources, indoor environmental quality, high-tech applications, adaptability, and concern for people are being given more attention by both SB and BSAT. On the other hand, the difference between them is that SB research focuses on more macro aspects, such as policy, culture, climate change, while BSAT research is more concerned with micro aspects, such as its system of tools. Furthermore, some current research gaps in the BSAT field are identified, clarifying its future research directions. By linking the evolution of the SB concept and the development of the BSAT research field, this review provides a new and valuable perspective for the sustainable assessment of the construction industry, which, itself, is conducive to the sustainable transformation of this industry, which could contribute greatly to the mitigation of global climate change.

Comparison of Different Monetization Methods in LCA: A Review

Different LCA methods based on monetization of environmental impacts are available. Therefore, relevant monetization methods, namely Ecovalue12, Stepwise2006, LIME3, Ecotax, EVR, EPS, the Environmental Prices Handbook, Trucost and the MMG-Method were compared quantitatively and qualitatively, yielding results for 18 impact categories. Monetary factors for the same impact category range mostly between two orders of magnitude for the assessed methods, with some exceptions (e.g., mineral resources with five orders of magnitude). Among the qualitative criteria, per capita income, and thus the geographical reference, has the biggest influence on the obtained monetary factors. When the monetization methods were applied to the domestic yearly environmental damages of an average EU citizen, their monetary values ranged between 7941.13 €/capita (Ecotax) and 224.06 €/capita (LIME3). The prioritization of impact categories varies: Stepwise and Ecovalue assign over 50% of the per capita damages to climate change, while EPS and LIME3 assign around 50% to mineral and fossil resource use. Choices regarding the geographical reference, the Areas of Protection included, cost perspectives and the approach to discounting strongly affect the magnitude of the monetary factors. Therefore, practitioners should choose monetization methods with care and potentially apply varying methods to assess the robustness of their results.

Towards Sustainable Neighborhoods in Europe: Mitigating 12 Environmental Impacts by Successively Applying 8 Scenarios

The purpose of this research is to determine the most impactful and important source of environmental change at the neighborhood level. The study of multiple scenarios allows us to determine the influence of several parameters on the results of the life cycle analysis of the neighborhood. We are looking at quantifying the impact of orientation, storm water management, density, mobility and the use of renewable energies on the environmental balance sheet of a neighborhood, based on eleven environmental indicators. An eco-neighborhood, located in Belgium, has been selected as the modeling site. The results show that the management of mobility is the parameter that can reduce the impact the most, in terms of greenhouse effect, odor, damage to biodiversity and health. With the adaptation of photovoltaic panels on the site, the production exceeds the consumption all through the year, except for the months of December and January, when the installation covers 45% and 75% of the consumption, respectively. Increasing the built density of the neighborhood by roof stacking allows the different environmental impacts, calculated per inhabitant, to be homogeneously minimized.

SDG-Based Sustainability Assessment Methodology for Innovations in the Field of Urban Surfaces

The sustainability of urban surfaces can be enhanced by introducing innovations. An ex-ante assessment of the potential sustainability impacts of innovations in urban areas can provide decision-makers with valuable recommendations for their selection before implementation. This knowledge helps to make the innovation more future-proof. Although a first methodological approach for such an assessment is available, there is no readily applicable set of indicators. Hence, this article proposes a holistic sustainability impact assessment method tailored to the management of urban surfaces and their innovations. For the development of the method, a Sustainable Development Goal (SDG)-based, top-down approach is adopted. The proposed assessment method makes it possible to identify an innovation’s potential contribution to the achievement of the SDGs before its introduction. In this article, the assessment method is tested by evaluating the sustainability impacts of weed-suppressing joint filling sand on a walkway in a municipal cemetery in Southern Germany. The case study shows that a mixed impact of the innovation in the three dimensions of sustainability could be expected within the system boundary. It highlights the need for innovation optimization, mainly in the economic dimension. As a result, the introduced method can support the innovation process of urban surfaces for sustainable municipal development.

The environmental impact of rock support for road tunnels: The experience of Norway

Despite the high levels of investment in the construction of underground space, there has been relatively little research so far on the environmental impact of tunnelling and rock support. In an attempt to fill this gap, this paper explores and compares the environmental impact of rock support on road-tunnel design in Norway for different rock-mass classes and tunnel sizes. Norwegian rock-support practices in road-tunnelling over the last twenty years are used to estimate figures for the consumption of material, equipment and energy. The background data are drawn from various Ecoinvent databases and environmental product declarations for major materials. The results indicate: 1) that the global warming potential (GWP) varies from 1 ton to 3.6 t per meter of rock support for different tunnel sizes and rock masses; 2) that all the environmental impacts of the shotcreting (or concrete-spraying) process are significantly greater than of all other processes; 3) that when a tunnel becomes larger or the rock mass becomes poorer, the relative contribution of the bolting process will increase; 4) that all environmental impacts are more sensitive to rock-class than to cross-section parameters; and 5) that potential improvements include reducing rebound, better designs of shotcrete admixtures and binders, improving durability and mechanical properties, and implementing the GWP or other environmental indicators during the design and tendering stages.

Environmental comparison of indoor floor coverings

Appropriate selection of construction materials plays a major role in a building's sustainable profile. The study sets out a comparative life cycle assessment of indoor flooring systems of different nature. The flooring systems consisted of coverings and, where required, bonding material and/or impact soundproofing material. The following coverings were assessed: inorganic (natural stone and ceramic tiles), polymer (carpeting and PVC), and wood-based (laminate and parquet) coverings. The life cycle assessment scope was defined cradle to cradle, i.e. product stage, transport to the construction site, installation of all construction elements, use, and valorisation by recycling, as end-of-life transition scenario towards a circular economy. In the use stage, three scenarios were defined as a function of pedestrian traffic intensity, which determined maintenance, repair, and replacement operations and frequencies. The environmental impacts of the coverings product stage were taken from previously assessed and selected Environmental Product Declarations (EPDs), as these are standardised public documents devised to provide environmental life cycle information. The method adopted in the study suggests that, though the use of EPDs as information source is interesting, erroneous conclusions may be drawn if the EPDs are not comparable and/or if the comparison is not made in the building context. The results indicate that the flooring systems with inorganic coverings performed best in the global warming, acidification, eutrophication, photochemical ozone creation, and abiotic depletion for fossil resources impact categories, whereas laminates performed best in the abiotic depletion for non-fossil resources and ozone layer depletion impact categories. The carpet flooring system performed worst in every impact category except photochemical ozone creation potential.

LCA-based Comparison of Two Organic Fraction Municipal Solid Waste Collection Systems in Historical Centres in Spain

Municipal solid waste (MSW) collection is an important issue in the development and management of smart cities, having a significant influence on environmental sustainability. Door-to-door and pneumatic collection are two systems that represent a way of arranging waste collection in city´s historic areas in Spain where conventional street-side container collection is not feasible. Since door-to-door collection generates significant direct greenhouse gas emissions from trucks, pneumatic collection emerges as an alternative to the trucking system. While this technology apparently reduces local direct air emissions, it suffers from a large energy demand derived from vacuum production for waste suction. The introduction of new normative frameworks regarding the selective collection of the biodegradable fraction makes necessary a comprehensive analysis to assess the influence of this fraction collection and its subsequent recycling by anaerobic digestion. As a novelty, this work compares both conventional door-to-door and pneumatic collection systems from a life cycle approach focusing on the biodegradable waste. Results indicate that, in spite of the fact electricity production and consumption have a significant influence on the results, the energy savings from the recycling of the organic fraction are higher than the energy requirements. Therefore, the pneumatic collection could be an environmentally-friendly option for MSW management under a circular economy approach in Spanish city´s historic areas, since wastes could be a material or energy source opportunity.

Technical feasibility and life cycle assessment of an industrial waste as stabilizing product for unpaved roads, and influence of packaging

The use of industrial solid wastes with a high content of SiO₂ and Al₂O₃, called "precursors", is often studied in the construction industry when combined with NaOH as "activator". The precursor and activator system is generally proposed as a binder material with similar characteristics to Portland cement. In this work, we technically and environmentally evaluated such a system elaborated with an industrial waste: coal ash with caustic soda in solid state. This product, mixed with the soil, acts as a stabilizer to increase the capacity of load support, allowing the improvement of the conditions of performance in low volume traffic roads. An experimental design applied to the stabilizing product showed the incidence of different factors on the load carrying capacity response: packaging material, type of seal, baling moisture and storage humidity. The application of the stabilizer product was found to increase the resistance of the ground over a 500%. Finally, the environmental aspects were evaluated through a simplified Life Cycle Assessment methodology (LCA), the scope of the study was restricted to cradle to gate, collecting data up to the packaged stabilizing product. The results showed that the highest impacts were caused, for most impact categories, by NaOH production, and transport was relevant as well.

Servitization in Support of Sustainable Cities: What Are Steel’s Contributions and Challenges?

In the pursuit of eco-efficiency, resilience, and self-sufficiency, sustainable cities focus on long-term environmental goals instead of only short-term economic ones. To do so, many of them rely on servitization, the practice of replacing tangible solutions for intangible ones. Considering steel’s wide range of applications and its pervasive presence, this article’s goal was twofold: Not only to understand how servitization helps sustainable cities, but also the contributions and challenges of the steel present in service-providing. To do so, the criteria of sustainable urban metabolism and circles of sustainability were used to analyze three case studies of servitization: energy, housing, and mobility. The results showed that servitization can provide significant benefits to sustainable cities, while also being able to substantially alter the supply-side dynamics of steelmaking by affecting, most notably, demand. This brought to light how important it is for steelmakers to pay close attention to the service-providing initiatives that may concern their clients and products. Nevertheless, further research is necessary to fully understand all of the effects that servitization can have on all of the commodities involved in its implementation.

First steps in life cycle assessments of cities with a sustainability perspective: A proposal for goal, function, functional unit, and reference flow

This study highlights the need and suggests some basis for working on the Life Cycle Assessment (LCA) of cities with a sustainability perspective. Cities are relevant actors in sustainable development and contribute to the generation of significant environmental impacts upstream and downstream their internal activity. LCA is precise in assessing environmental aspects of sustainability but lacks social and economic inputs. It is important to avoid problem shifting, even between the different dimensions of sustainability. A systematic literature review has been performed so as to extract the procedure for defining the goal, function, functional unit, and reference flow of a complex system. The existing literature is mainly product focused, although services are also considered somehow. The procedure for defining the abovementioned items is previously applied to a relatively simple system, a power generation plant, so as to find parallelisms to define those items for a complex system such as a city. To obtain a feasible (i.e., simplified) city Life Cycle Sustainability Assessment, the authors propose to introduce the social and economic aspects through the use of the City Prosperity Index (CPI) as technical performance within the FU of the city LCA. The CPI combined with the number of inhabitants is the normalization factor which is found to be more suitable to avoid problem shifting among sustainability dimensions and to avoid the interference of the number of inhabitants when comparing two different cities. An exemplification of the variation of the results after the application of these two factors in 18 cities' CO₂-eq emissions is described. Even though this is not a large sample, it includes cities from different continents and levels of development and, thus it can be useful to see the how the suggested method is affecting cities' ranking.

Understanding urban water performance at the city-region scale using an urban water metabolism evaluation framework

Water sensitive interventions are being promoted to reduce the adverse impacts of urban development on natural water cycles. However it is currently difficult to know the best strategy for their implementation because current and desired urban water performance is not well quantified. This is particularly at the city-region scale, which is important for strategic urban planning. This work aimed to fill this gap by quantifying the water performance of urban systems within city-regions using 'urban water metabolism' evaluation, to inform decisions about water sensitive interventions. To do this we adapted an existing evaluation framework with new methods. In particular, we used land use data for defining system boundaries, and for estimating natural hydrological flows. The criteria for gauging the water performance were water efficiency (in terms of water extracted externally) and hydrological performance (how much natural hydrological flows have changed relative to a nominated pre-urbanised state). We compared these performance criteria for urban systems within three Australian city-regions (South East Queensland, Melbourne and Perth metropolitan areas), under current conditions, and after implementation of example water sensitive interventions (demand management, rainwater/stormwater harvesting, wastewater recycling and increasing perviousness). The respective water efficiencies were found to be 79, 90 and 133 kL/capita/yr. In relation to hydrological performance, stormwater runoff relative to pre-urbanised flows was of most note, estimated to be 2-, 6- and 3- fold, respectively. The estimated performance benefits from water sensitive interventions suggested different priorities for each region, and that combined implementation of a range of interventions may be necessary to make substantive gains in performance. We concluded that the framework is suited to initial screening of the type and scale of water sensitive interventions needed to achieve desired water performance objectives.