Country-Specific External Costs of Abiotic Resource Use Based on User Cost Model in Life Cycle Impact Assessment.

Abiotic resources are indispensable in society, but there are concerns regarding their depletion, scarcity, and increasing prices, resulting in potential economic damage in the future. To address these concerns, it is effective to consider the external costs of resource use. Although resource availability is different among mining sites, and local conditions are relevant in assessing resource scarcity, previous studies have assessed external costs and potential impacts of abiotic resource use globally. This study provides country-specific characterization factors (CFs) of abiotic resource use in life cycle impact assessment based on the user cost model, which represents the external costs of abiotic resource use to reflect country-specific resource scarcity. We demonstrate considerable variations in the CFs depending on the mining country, suggesting that the choice of mining country can affect external costs. The global external cost of abiotic resource use in 2020 was estimated at 1.9 trillion $, with a major contribution from the extraction of fossil fuels in the United States. Historical trends of the CFs and relevant parameters showed temporal fluctuations, emphasizing the importance of regularly updating the data underlying the calculation of the CFs. Country-level assessments of the external costs of resource use can contribute to discussions on the responsibilities of consuming countries by incorporating material footprint studies.

Responsibility of consumers for mining capacity: decomposition analysis of scarcity-weighted metal footprints in the case of Japan.

Metal-consuming countries depend on mining activity in other countries, which may impose potential pressure on sustainable metal supply. This study proposes an approach to analyze the responsibility of consuming countries for mining activities based on the decomposition analysis of scarcity-weighted metal footprints (S-MFs) of Japan. The application results to the Japanese final demand (iron, copper, and nickel) demonstrate the significance of country- and metal-specific conditions in terms of metal footprints and mining capacity in assessing the responsibility of consuming countries. Consuming countries can identify influential factors to reduce their S-MFs based on the decomposition analysis by discriminating the directly controllable and uncontrollable factors for consuming countries, which can help to plan different countermeasures depending on the types of the identified influential factors. The proposed approach supports metal-consuming countries to determine the effective options for reducing the responsibility for the sustainability of metal supply.

Regional Carrying Capacities of Freshwater Consumption-Current Pressure and Its Sources.

Sustainable freshwater management is an essential target for sustainability. The concept of planetary boundaries evaluates whether the environmental loads from humans are within the carrying capacity of the environment at a global level, while the region-specific assessment of carrying capacities of freshwater consumption can complement the global-scale sustainability assessment by shedding light on regional sustainability. We show that 24% of the total freshwater consumption exceeds the regional carrying capacities based on spatially and temporally explicit analysis (monthly data for around 11 000 watersheds). Although 19% of the current total freshwater consumption is determined as "luxury consumption" beyond basic needs, approximately 60% of the exceedance is attributed to basic needs of freshwater for sustaining human life. International trade alleviates the overall pressure on carrying capacity by approximately 4.8% (18.9 billion m3) at a global level through virtual water trade; however, several producer countries demonstrate additional overconsumption beyond the regional carrying capacities, while importer countries that can do so mitigate overconsumption. Appropriate irrigation water management and the location of crop production are the keys to maintain our freshwater consumption levels within the regional carrying capacities on a global scale. However, measures that necessitate the consideration of watershed-specific environmental and economic conditions are desirable.

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.

Understanding the LCA and ISO water footprint: A response to Hoekstra (2016) "A critique on the water-scarcity weighted water footprint in LCA".

Water footprinting has emerged as an important approach to assess water use related effects from consumption of goods and services. Assessment methods are proposed by two different communities, the Water Footprint Network (WFN) and the Life Cycle Assessment (LCA) community. The proposed methods are broadly similar and encompass both the computation of water use and its impacts, but differ in communication of a water footprint result. In this paper, we explain the role and goal of LCA and ISO-compatible water footprinting and resolve the six issues raised by Hoekstra (2016) in "A critique on the water-scarcity weighted water footprint in LCA". By clarifying the concerns, we identify both the overlapping goals in the WFN and LCA water footprint assessments and discrepancies between them. The main differing perspective between the WFN and LCA-based approach seems to relate to the fact that LCA aims to account for environmental impacts, while the WFN aims to account for water productivity of global fresh water as a limited resource. We conclude that there is potential to use synergies in research for the two approaches and highlight the need for proper declaration of the methods applied.