• Energy Research

Clay-fired bricks are widely used in emerging economies mainly because of the unavailability of higher-grade construction and building materials; however, they are associated with significant social and environmental damage. The environmental burdens associated with the fuels and materials required for brick production are huge, as they have both direct and indirect effects along supply chains. This study aimed to assess the environmental footprints of brick production along supply chains, focusing on relevant environmental issues in brick production: carbon dioxide emissions, water consumption, and land use. We demonstrate that fuelwood consumption constitutes a major share of the carbon and water footprints, whereas built-up land for brick drying dominates the major effect of land use. Our expansion of the ecological footprint method enables a comparison of the effects of three different environmental issues with the same land area dimension, which reveals the relative severity of carbon dioxide emissions that account for up to 20% of the national CO2 inventory. For the potential reduction in the environmental footprint of brick production, scenario analysis showed a substantial reduction by replacing clay-fired bricks with concrete bricks. The shift to alternative materials, together with mitigation measures for brick production, can effectively alleviate the environmental pressures of construction materials in future emerging economies.

Clay-fired bricks are widely used in emerging economies mainly because of the unavailability of higher-grade construction and building materials; however, they are associated with significant social and environmental damage. The environmental burdens associated with the fuels and materials required for brick production are huge, as they have both direct and indirect effects along supply chains. This study aimed to assess the environmental footprints of brick production along supply chains, focusing on relevant environmental issues in brick production: carbon dioxide emissions, water consumption, and land use. We demonstrate that fuelwood consumption constitutes a major share of the carbon and water footprints, whereas built-up land for brick drying dominates the major effect of land use. Our expansion of the ecological footprint method enables a comparison of the effects of three different environmental issues with the same land area dimension, which reveals the relative severity of carbon dioxide emissions that account for up to 20% of the national CO2 inventory. For the potential reduction in the environmental footprint of brick production, scenario analysis showed a substantial reduction by replacing clay-fired bricks with concrete bricks. The shift to alternative materials, together with mitigation measures for brick production, can effectively alleviate the environmental pressures of construction materials in future emerging economies.

Purpose Life cycle assessment (LCA) has been used to assess freshwater-related impacts according to a new water footprint framework formalized in the ISO 14046 standard. To date, no consensus-based approach exists for applying this standard and results are not always comparable when different scarcity or stress indicators are used for characterization of impacts. This paper presents the outcome of a 2-year consensus building process by the Water Use in Life Cycle Assessment (WULCA), a working group of the UNEP-SETAC Life Cycle Initiative, on a water scarcity midpoint method for use in LCA and for water scarcity footprint assessments. Methods In the previous work, the question to be answered was identified and different expert workshops around the world led to three different proposals. After eliminating one proposal showing low relevance for the question to be answered, the remaining two were evaluated against four criteria: stakeholder acceptance, robustness with closed basins, main normative choice, and physical meaning. Results and discussion The recommended method, AWARE, is based on the quantification of the relative available water remaining per area once the demand of humans and aquatic ecosystems has been met, answering the question “What is the potential to deprive another user (human or ecosystem) when consuming water in this area?” The resulting characterization factor (CF) ranges between 0.1 and 100 and can be used to calculate water scarcity footprints as defined in the ISO standard. Conclusions After 8 years of development on water use impact assessment methods, and 2 years of consensus building, this method represents the state of the art of the current knowledge on how to assess potential impacts from water use in LCA, assessing both human and ecosystem users’ potential deprivation, at the midpoint level, and provides a consensus-based methodology for the calculation of a water scarcity footprint as per ISO 14046. The International Journal of Life Cycle Assessment, 23 (2) ISSN:0948-3349 ISSN:1614-7502

Purpose Life cycle assessment (LCA) has been used to assess freshwater-related impacts according to a new water footprint framework formalized in the ISO 14046 standard. To date, no consensus-based approach exists for applying this standard and results are not always comparable when different scarcity or stress indicators are used for characterization of impacts. This paper presents the outcome of a 2-year consensus building process by the Water Use in Life Cycle Assessment (WULCA), a working group of the UNEP-SETAC Life Cycle Initiative, on a water scarcity midpoint method for use in LCA and for water scarcity footprint assessments. Methods In the previous work, the question to be answered was identified and different expert workshops around the world led to three different proposals. After eliminating one proposal showing low relevance for the question to be answered, the remaining two were evaluated against four criteria: stakeholder acceptance, robustness with closed basins, main normative choice, and physical meaning. Results and discussion The recommended method, AWARE, is based on the quantification of the relative available water remaining per area once the demand of humans and aquatic ecosystems has been met, answering the question “What is the potential to deprive another user (human or ecosystem) when consuming water in this area?” The resulting characterization factor (CF) ranges between 0.1 and 100 and can be used to calculate water scarcity footprints as defined in the ISO standard. Conclusions After 8 years of development on water use impact assessment methods, and 2 years of consensus building, this method represents the state of the art of the current knowledge on how to assess potential impacts from water use in LCA, assessing both human and ecosystem users’ potential deprivation, at the midpoint level, and provides a consensus-based methodology for the calculation of a water scarcity footprint as per ISO 14046. The International Journal of Life Cycle Assessment, 23 (2) ISSN:0948-3349 ISSN:1614-7502

All relevant effects on water must be assessed in water footprinting for identifying hotspots and managing the impacts of products, processes, and services throughout the life cycle. Although several studies have focused on physical water scarcity and degradation of water quality, the relevance of land use in water footprinting has not been widely addressed. Here, we aimed to verify the extent of land-use effect in the context of water footprinting. Intensity factors of land use regarding the loss of freshwater availability are modeled by calculating water balance at grid scale in Japan. A water footprint inventory and impacts related to land use are assessed by applying the developed intensity factors and comparing them with those related to water consumption and degradation. Artificial land use such as urban area results in the loss of many parts of available freshwater input by precipitation. When considering water footprint inventory, the dominance of land use is less than that of water consumption. However, the effect of land use is relevant to the assessment of water footprint impact by differentiating stress on water resources. The exclusion of land use effect underestimates the water footprint of goods produced in Japan by an average of around 37%.

All relevant effects on water must be assessed in water footprinting for identifying hotspots and managing the impacts of products, processes, and services throughout the life cycle. Although several studies have focused on physical water scarcity and degradation of water quality, the relevance of land use in water footprinting has not been widely addressed. Here, we aimed to verify the extent of land-use effect in the context of water footprinting. Intensity factors of land use regarding the loss of freshwater availability are modeled by calculating water balance at grid scale in Japan. A water footprint inventory and impacts related to land use are assessed by applying the developed intensity factors and comparing them with those related to water consumption and degradation. Artificial land use such as urban area results in the loss of many parts of available freshwater input by precipitation. When considering water footprint inventory, the dominance of land use is less than that of water consumption. However, the effect of land use is relevant to the assessment of water footprint impact by differentiating stress on water resources. The exclusion of land use effect underestimates the water footprint of goods produced in Japan by an average of around 37%.