Supply Chain Factors Contributing to Improved Material Flow Indicators but Increased Carbon Footprint.

Improvements in four material flow indicators (MFIs) have helped facilitate Japan's transition to a sound material-cycle society. However, the economic and technological factors that have affected these MFIs have not been identified previously. Moreover, it is unclear whether the improvements in the MFIs have contributed to Japan's progress toward carbon mitigation. In this study, we quantified the contribution of the factors in the capital-embodied supply chain to changes in the MFIs at the national and sector levels. We also examined the consistency of MFI improvements with carbon footprint reduction. Our results show that, in many sectors, structural changes in the supply chain improved two of the MFIs (resource productivity and material circularity) but increased the carbon footprint of the sector. To address this conflict, producers need to manage their supply chains based on an understanding of the nexus between material consumption and carbon emissions, paying particular attention to supply chains associated with capital formation.

Efficient use of cement and concrete to reduce reliance on supply-side technologies for net-zero emissions.

Decarbonization strategies for the cement and concrete sector have relied heavily on supply-side technologies, including carbon capture and storage (CCS), masking opportunities for demand-side intervention. Here we show that cross-cutting strategies involving both the supply and demand sides can achieve net-zero emissions by 2050 across the entire Japanese cement and concrete cycle without resorting to mass deployment of CCS. Our analysis shows that a series of mitigation efforts on the supply side can reduce 2050 CO2 emissions by up to 80% from baseline levels and that the remaining 20% mitigation gap can be fully bridged by the efficient use of cement and concrete in the built environment. However, this decarbonization pathway is dependent on how CO2 uptake by carbonation and carbon capture and utilization is accounted for in the inventory. Our analysis underscores the importance of including demand-side interventions at the heart of decarbonization strategies and highlights the urgent need to discuss how to account for CO2 uptake in national inventories under the Paris Agreement.

Consumption in the G20 nations causes particulate air pollution resulting in two million premature deaths annually.

Worldwide exposure to ambient PM2.5 causes over 4 million premature deaths annually. As most of these deaths are in developing countries, without internationally coordinated efforts this polarized situation will continue. As yet, however, no studies have quantified nation-to-nation consumer responsibility for global mortality due to both primary and secondary PM2.5 particles. Here we quantify the global footprint of PM2.5-driven premature deaths for the 19 G20 nations in a position to lead such efforts. G20 consumption in 2010 was responsible for 1.983 [95% Confidence Interval: 1.685-2.285] million premature deaths, at an average age of 67, including 78.6 [71.5-84.8] thousand infant deaths, implying that the G20 lifetime consumption of about 28 [24-33] people claims one life. Our results indicate that G20 nations should take responsibility for their footprint rather than focusing solely on transboundary air pollution, as this would expand opportunities for reducing PM2.5-driven premature mortality. Given the infant mortality footprint identified, it would moreover contribute to ensuring infant lives are not unfairly left behind in countries like South Africa, which have a weak relationship with G20 nations.

Critical supply chains for mitigating PM2.5 emission-related mortalities in India.

Air pollution and its health-related effects are a major concern globally, and many people die from air pollution-related diseases each year. This study employed a structural path analysis combined with a health impact inventory database analysis to estimate the number of consumption-based PM2.5 emission-related deaths attributed to India's power supply sector. We identified critical supply chain paths for direct (production) electricity use and indirect (consumption) use. We also considered both domestic and foreign final demand and its effect on PM2.5 emission-related deaths. Several conclusions could be drawn from our results. First, the effect of indirect electricity usage on PM2.5 emission-related deaths is approximately four times larger than that for direct usage. Second, a large percentage of pollution-related deaths can be attributed to India's domestic final demand usage; however, electricity usage in the intermediate and final demand sectors is inextricably linked. Third, foreign final demand sectors from the Middle East, the USA, and China contribute indirectly toward PM2.5 emission-related deaths, specifically in the rice export supply chain. The results show that the Indian government should implement urgent measures to curb electricity use in rice supply chains in order to reduce the number of PM2.5 emission-related deaths.

Forest Tax Payment Responsibility from the Forest Service Footprint Perspective.

It has been observed that market failure has hampered the development of sustainable forest ecosystem services such as CO2 absorption and fixation, water retention, and biodiversity. One of the reasons for this is that the link between forest land use and the beneficiaries of that use has not been widely recognized or clearly established. To address this problem, we conducted a footprint analysis to clarify the linkage between Japanese taxpayers as the beneficiaries of forest land use and the use of tax revenue and monetary donations for forest management. This study focuses on how the current forest tax collected from Japanese taxpayers (63 billion Japanese yen) could be allocated more fairly. The question of whether the collected taxes are sufficient is left for another time. At the core of our analysis, we examined the carbon footprint and established a linkage between the origins of CO2 emissions in Japan and their destinations by using a subnational multiregional input-output database and building a base table focused on various land use types and subnational regions at the municipality level. By clarifying these linkages and enhancing their transparency, we provide a basis for developing alternative financing schemes involving both taxation and taxpayer donations in support of forest management activities and protection of biodiverse habitats.

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.

Global Metal Use Targets in Line with Climate Goals.

Metals underpin essential functions in modern society, yet their production currently intensifies climate change. This paper develops global targets for metal flows, stocks, and use intensity in the global economy out to 2100. These targets are consistent with emissions pathways to achieve a 2 °C climate goal and cover six major metals (iron, aluminum, copper, zinc, lead, and nickel). Results indicate that despite advances in low-carbon metal production, a transformative system change to meet the society's needs with less metal is required to remain within a 2 °C pathway. Globally, demand for goods and services over the 21st century needs to be met with approximately 7 t/capita of metal stock-roughly half the current level in high-income countries. This systemic change will require a peak in global metal production by 2030 and deep decoupling of economic growth from both metal flows and stocks. Importantly, the identified science-based targets are theoretically achievable through such measures as efficient design, more intensive use, and longer product lifetime, but immediate action is crucial before middle- and low-income countries complete full-scale urbanization.

Global socio-economic losses and environmental gains from the Coronavirus pandemic.

On 3 April 2020, the Director-General of the WHO stated: "[COVID-19] is much more than a health crisis. We are all aware of the profound social and economic consequences of the pandemic (WHO, 2020)". Such consequences are the result of counter-measures such as lockdowns, and world-wide reductions in production and consumption, amplified by cascading impacts through international supply chains. Using a global multi-regional macro-economic model, we capture direct and indirect spill-over effects in terms of social and economic losses, as well as environmental effects of the pandemic. Based on information as of May 2020, we show that global consumption losses amount to 3.8$tr, triggering significant job (147 million full-time equivalent) and income (2.1$tr) losses. Global atmospheric emissions are reduced by 2.5Gt of greenhouse gases, 0.6Mt of PM2.5, and 5.1Mt of SO2 and NOx. While Asia, Europe and the USA have been the most directly impacted regions, and transport and tourism the immediately hit sectors, the indirect effects transmitted along international supply chains are being felt across the entire world economy. These ripple effects highlight the intrinsic link between socio-economic and environmental dimensions, and emphasise the challenge of addressing unsustainable global patterns. How humanity reacts to this crisis will define the post-pandemic world.

Our health, our planet: a cross-sectional analysis on the association between health consciousness and pro-environmental behavior among health professionals.

One possible predictive factor that affects both pro-environmental behavior and health behavior is health consciousness (a psychological state where an individual is aware of and involved in his/her health condition). We examined the relationship between health consciousness and two pro-environmental behaviors (recycling and green purchasing) within health professionals in a Japanese large hospital. Multivariate linear regression analysis revealed a significant association between health consciousness and recycling behavior, while there was no association between health consciousness and green purchasing behavior. We assume that health consciousness can certainly be a factor promoting pro-environmental behavior, but that it may have been insufficient to cause green purchasing, because of the organizational norm of recycling in the Japanese context. Given that there is previous evidence about the relationship between health consciousness and health behavior, health consciousness might be a predictive factor that encourages both health behavior and pro-environmental behavior simultaneously.

Affluent countries inflict inequitable mortality and economic loss on Asia via PM2.5 emissions.

This research sets out to quantify the mortality and economic loss in individual Asian countries caused by the PM2.5 emissions induced by the consumption of the world's five highest-consuming countries (US, China, Japan, Germany, UK). In 2010 alone, the economic impact of these five countries' consumption caused a loss of almost 45 billion US dollars due to the premature deaths of more than 1 million people in Asia, including 15 thousand children younger than 5 years old. The percentage ratio of economic loss to value-added driven by consumers via trade differed greatly among the impacted countries. For the US, the highest percentage loss was 4.1% in Laos, followed by 2.0% in Bangladesh, both markedly higher than the figures for the more developed countries, such as 0.21% for Japan and 0.18% for Korea. This reflects the inequitable value chain existing between consumer countries and impacted countries, and implies that developing countries are obtaining value-added in exchange for unintentionally increased health risks, delaying their development and potentially creating a vicious circle that hinders much-needed improvements in areas like poverty reduction and public health. This inequitable situation needs to be redressed through introduction of clean energy and other types of technological assistance to help achieve United Nations Sustainable Development Goals 7, 10 and 13. Such as move is essential if premature infant deaths are to be curtailed.

Clarifying Demographic Impacts on Embodied and Materially Retained Carbon toward Climate Change Mitigation.

Modern lifestyles demand a number of products derived from petroleum-based sources that eventually cause carbon emissions. The quantification of lifestyle and household consumption impacts upon carbon emissions from both the embodied CO2 (EC) and materially retained carbon (MRC) viewpoints is critical to deriving amelioration policies and meeting emission reduction goals. This study, for the first time, details a methodology to estimate both EC and MRC for Japan, focusing on petrochemicals and woody products utilizing the time series input-output table, physical value tables and the national survey of family income and expenditure, leveraging time series input-output-based material flow analysis (IO-MFA), and structural decomposition analysis (SDA). Findings elucidated hot spots of deleterious consumption by age of householder and the critical factors which underpin them including intensity effects, pattern effects, and demographic shifts over time. Although demographic shifts associated with an aging, shrinking population in Japan decreased EC and MRC, the negative effect reduced in size over time during 1990-2005. Policy implications identify the potential to mitigate approximately 21% of required household emission reductions by 2030 through strategies including recycling initiatives and the recovery of carbon from products covered within current recycling laws and hot spot sectors which are not currently considered such as apparel.

Integrating Circular Economy Strategies with Low-Carbon Scenarios: Lithium Use in Electric Vehicles.

Electrification of the transport sector will support its decarbonization, yet significantly change material requirements. This calls for an integrated modeling approach internalizing metal demand-supply dynamics in low-carbon scenarios to support the Paris agreement on climate change and sustainable material circulation. Here we develop a step toward the integrated simulation of energy-materials scenarios by unifying a stock-flow dynamics model for low-carbon scenarios using linear programming. The modeling framework incorporates lithium supply from both mines and end-of-life (EoL) recycling for projected use in electric vehicles on a global basis. The results show that supply constraints, which could become apparent from around 2030 in the case of current recycling rates (<1%), would impede the deployment of battery electric vehicles (BEVs), leading to the generation of an additional 300 Mt-CO2 of emissions for vehicle operation in 2050. Another important finding is that increasing the recycling rate to 80% could substantially relieve restrictions on the introduction of BEVs without requiring primary supply from natural deposits far beyond historical rates of expansion. While EoL recycling is important from a long-term perspective, an EoL-oriented strategy has little effect on the short/medium-term (such as to 2030) lithium demand-supply balance because of exponential demand growth and long living batteries. Importantly, findings in this study emphasize the necessity of tackling climate change and resource circulation in an integrated manner.

Global Distribution of Used and Unused Extracted Materials Induced by Consumption of Iron, Copper, and Nickel.

In today's global economy, sustainable resource management requires a consumption perspective of resource use and insight into actual resource use through the global supply chain. The estimated global amount of used and unused extraction caused by mineral extraction of iron, copper, and nickel more than doubled from 1990 to 2013 (iron, 2.8-6.7 Pg; copper, 2.7-5.5 Pg; nickel, 0.19-0.60 Pg). By incorporating global material flow into a global link input-output model (GLIO, a hybrid multiregional IO model), we estimated the total used and unused extraction caused by iron, copper, and nickel mining induced by Japanese final demand to be 0.44, 0.52, and 0.043 Pg in 2011, respectively, equivalent to 7.1% of the total global extraction amount caused by iron mining, 11% of the amount caused by copper mining, and 10% of the amount caused by nickel mining. Whereas the world extraction total caused by iron, copper, and nickel mining rapidly increased from 2005 to 2011, the extraction amount induced by Japanese final demand for the same period either stayed about the same (iron) or decreased slightly (copper, 99% of the 2005 amount; nickel, 92%).

Global land-use change hidden behind nickel consumption.

Economic growth is associated with a rapid rise in the use of natural resources within the economy, and has potential environmental impacts at local and/or global scales. In today's globalized economy, each country has indirect flows supporting its economic activities, and natural resource consumption through supply chains influences environmental impacts far removed from the place of consumption. One way to control environmental impacts associated with consumption of natural resources is to identify the consumption of natural resources and the associated environmental impacts through the global supply chain. In this study, we used a global link input-output model (GLIO, a hybrid multiregional input-output model) to detect the linkages between national nickel consumption and mining-associated global land-use changes. We focused on nickel, whose global demand has risen rapidly in recent years, as a case study. The estimated area of land-use change around the world caused by nickel mining in 2005 was 1.9km2, and that induced by Japanese final demand for nickel was 0.38km2. Our modeling also revealed that the areas of greatest land-use change associated with nickel mining were concentrated in only a few countries and regions far removed from the place of consumption. For example, 57.7% of the world's land-use changes caused by nickel mining were concentrated in five countries in 2005: Australia, 13.7%; Russia, 12.9%; Indonesia, 12.5%; New Caledonia, 10.4%; and Colombia, 8.2%. The mining-associated land-use change induced by Japanese final demand accounted for 19.5% of the total area affected by land-use change caused by nickel mining. The top three countries accounted for 70.6% (Indonesia: 47.0%, New Caledonia: 16.0%, and Australia: 7.7%), and the top five accounted for 82.4% (the Philippines: 7.5%, and Canada: 4.3%, in addition to the top three countries and regions).

Nitrogen footprints: Regional realities and options to reduce nitrogen loss to the environment.

Nitrogen (N) management presents a sustainability dilemma: N is strongly linked to energy and food production, but excess reactive N causes environmental pollution. The N footprint is an indicator that quantifies reactive N losses to the environment from consumption and production of food and the use of energy. The average per capita N footprint (calculated using the N-Calculator methodology) of ten countries varies from 15 to 47 kg N capita-1 year-1. The major cause of the difference is the protein consumption rates and food production N losses. The food sector dominates all countries' N footprints. Global connections via trade significantly affect the N footprint in countries that rely on imported foods and feeds. The authors present N footprint reduction strategies (e.g., improve N use efficiency, increase N recycling, reduce food waste, shift dietary choices) and identify knowledge gaps (e.g., the N footprint from nonfood goods and soil N process).

Global mining risk footprint of critical metals necessary for low-carbon technologies: the case of neodymium, cobalt, and platinum in Japan.

Meeting the 2-degree global warming target requires wide adoption of low-carbon energy technologies. Many such technologies rely on the use of precious metals, however, increasing the dependence of national economies on these resources. Among such metals, those with supply security concerns are referred to as critical metals. Using the Policy Potential Index developed by the Fraser Institute, this study developed a new footprint indicator, the mining risk footprint (MRF), to quantify the mining risk directly and indirectly affecting a national economy through its consumption of critical metals. We formulated the MRF as a product of the material footprint (MF) of the consuming country and the mining risks of the countries where the materials are mined. A case study was conducted for the 2005 Japanese economy to determine the MF and MRF for three critical metals essential for emerging energy technologies: neodymium, cobalt and platinum. The results indicate that in 2005 the MFs generated by Japanese domestic final demand, that is, the consumption-based metal output of Japan, were 1.0 × 10(3) t for neodymium, 9.4 × 10(3) t for cobalt, and 2.1 × 10 t for platinum. Export demand contributes most to the MF, accounting for 3.0 × 10(3) t, 1.3 × 10(5) t, and 3.1 × 10 t, respectively. The MRFs of Japanese total final demand (domestic plus export) were calculated to be 1.7 × 10 points for neodymium, 4.5 × 10(-2) points for cobalt, and 5.6 points for platinum, implying that the Japanese economy is incurring a high mining risk through its use of neodymium. This country's MRFs are all dominated by export demand. The paper concludes by discussing the policy implications and future research directions for measuring the MFs and MRFs of critical metals. For countries poorly endowed with mineral resources, adopting low-carbon energy technologies may imply a shifting of risk from carbon resources to other natural resources, in particular critical metals, and a trade-off between increased mining risk and deployment of such technologies. Our analysis constitutes a first step toward quantifying and managing the risks associated with natural resource mining.

Changes in the carbon footprint of Japanese households in an aging society.

As the aging and low birthrate trends continue in Japan, and as changes in the working population and consumption patterns occur, new factors are expected to have an impact on consumption-based greenhouse gas (GHG) emissions. We present the impacts of changes in the composition of Japanese households on GHG emission structures using current (2005) consumption-based accounting on the commodity sectors that are expected to require priority efforts for reducing emissions in 2035. This is done using the Global Link Input-Output model (GLIO) and domestic household consumption data and assuming that recent detailed consumption expenditures based on the Social Accounting Matrix (SAM) will continue into the future. The results show that consumption-based GHG emissions derived from Japanese household consumption in 2035 are estimated to be 1061 Mt-CO2eq (4.2% lower than in 2005). This study can be used to reveal more information and as a resource in developing policies to more meticulously and efficiently reduce emissions based on emission and import rates for each domestic and overseas commodity supply chain.

Global flows of critical metals necessary for low-carbon technologies: the case of neodymium, cobalt, and platinum.

This study, encompassing 231 countries and regions, quantifies the global transfer of three critical metals (neodymium, cobalt, and platinum) considered vital for low-carbon technologies by means of material flow analysis (MFA), using trade data (BACI) and the metal contents of trade commodities, resolving the optimization problem to ensure the material balance of the metals within each country and region. The study shows that in 2005 international trade led to global flows of 18.6 kt of neodymium, 154 kt of cobalt, and 402 t of platinum and identifies the main commodities and top 50 bilateral trade links embodying these metals. To explore the issue of consumption efficiency, the flows were characterized according to the technological level of each country or region and divided into three types: green ("efficient use"), yellow ("moderately efficient use"), and red ("inefficient use"). On this basis, the shares of green, yellow, and red flows in the aggregate global flow of Nd were found to be 1.2%, 98%, and 1.2%, respectively. For Co, the respective figures are 53%, 28%, and 19%, and for Pt 15%, 84%, and 0.87%. Furthermore, a simple indicator focusing on the composition of the three colored flows for each commodity was developed to identify trade commodities that should be prioritized for urgent technical improvement to reduce wasteful use of the metals. Based on the indicator, we discuss logical, strategic identification of the responsibilities and roles of the countries involved in the global flows.

Estimates of embodied global energy and air-emission intensities of Japanese products for building a Japanese input-output life cycle assessment database with a global system boundary.

To build a life cycle assessment (LCA) database of Japanese products embracing their global supply chains in a manner requiring lower time and labor burdens, this study estimates the intensity of embodied global environmental burden for commodities produced in Japan. The intensity of embodied global environmental burden is a measure of the environmental burden generated globally by unit production of the commodity and can be used as life cycle inventory data in LCA. The calculation employs an input-output LCA method with a global link input-output model that defines a global system boundary grounded in a simplified multiregional input-output framework. As results, the intensities of embodied global environmental burden for 406 Japanese commodities are determined in terms of energy consumption, greenhouse-gas emissions (carbon dioxide, methane, nitrous oxide, perfluorocarbons, hydrofluorocarbons, sulfur hexafluoride, and their summation), and air-pollutant emissions (nitrogen oxide and sulfur oxide). The uncertainties in the intensities of embodied global environmental burden attributable to the simplified structure of the global link input-output model are quantified using Monte Carlo simulation. In addition, by analyzing the structure of the embodied global greenhouse-gas intensities we characterize Japanese commodities in the context of LCA embracing global supply chains.

High-resolution inventory of Japanese anthropogenic mercury emissions.

Heavy metals like mercury that are emitted into the environment remain there indefinitely, posing a long-term threat to both the environment and human health. Elemental mercury is volatile and is in gaseous form, and because of the long residence time, transported over long distances. Comprehensive control of mercury emissions therefore remains an important international issue. The crucial steps for designing effective approaches for such control include the quantification of mercury emissions by sources and the identification of geographical characteristics of the emissions. In this study a detailed, high-resolution inventory of Japanese mercury emissions in 2005 was developed to improve understanding of their geographical distribution. Proceeding from a national emissions inventory per source category, emissions were spatially allocated with increasing geographical resolution in a stepwise procedure using statistics from geographic information resources, yielding mercury emissions per prefecture, per municipality and per grid cell of approximately 1 × 1 km. The five prefectures with the highest emissions were Fukuoka, Yamaguchi, Hyogo, Oita, and Hokkaido, accounting for 35.2% of all emissions. In each prefecture a small number of municipalities account for a major share of emissions. Distribution by grid cell is characterized by a concentration of 50% of all emissions in a mere 32 of the 255 954 grid cells over which emissions are distributed in this study. It was also quantitatively confirmed that use of larger grid cells leads to greater uncertainty in emissions distribution. Problems with data collection are clarified and measures to improve the accuracy of future estimation are proposed.