Multiperspective Decoupling Analyses between Global Embodied Carbon Chains and Global Value Chains.

Decoupling global economic growth from carbon emissions is essential for mitigating global climate change while maintaining continuous economic growth. Traditional production-side decoupling analysis alone is insufficient to capture the decoupling status between carbon emissions and the value added throughout global supply chains. This study investigates the decoupling status between value added and greenhouse gas (GHG) emissions during 1995-2019 from consumption and income perspectives. We find that the decoupling statuses of 17 regions (especially Russia, Australia, and Malta) show significant differences across multiple perspectives. For example, Malta's direct GHG emissions decreased with its GDP growth from a production perspective (i.e., achieved strong decoupling). However, its consumption-based GHG emissions increased with the growth of consumption-based value added (i.e., expansive negative decoupling). Moreover, most international pairs have not yet achieved strong decoupling from consumption and income perspectives. International multilateral cooperation is crucial for decoupling global GHG emissions from economic growth across global supply chains. This study provides insights into the decoupling between embodied GHG emissions and value added from consumption and income perspectives. The findings of this study can complement existing policies on global GHG emission mitigation and sustainable development.

A high spatial resolution dataset for methylmercury exposure in Guangdong-Hong Kong-Macao Greater Bay Area.

Dietary methylmercury (MeHg) exposure increases the risk of many human diseases. The Guangdong-Hong Kong-Macao Greater Bay Area (GBA) is the world's most populous bay area and people there might suffer a high risk of dietary MeHg exposure. However, there lacks a time-series high spatial resolution dataset for dietary MeHg exposure in the GBA. This study constructs a high spatial resolution (1 km × 1 km) dataset for dietary MeHg exposure in the GBA during 2009-2019. It first constructs the dietary MeHg exposure inventory for each county/district of the GBA, based on MeHg concentrations of foods (i.e., rice and fish in this study) and per capita rice and fish intake. Subsequently, this study spatializes the dietary MeHg exposure inventory at 1 km × 1 km scale, using gridded data for food consumption expenditure as the proxy. This dataset can describe the spatially explicit hotspots, distribution patterns, and variation trend of dietary MeHg exposure in the GBA. This dataset can support spatially explicit evaluation of MeHg-related health risks in the GBA.

Double-edged sword of technological progress to climate change depends on positioning in global value chains.

Technological progress (TP) is a double-edged sword to global climate change. This study for the first time reveals rebound and mitigation effects of efficiency-related TP in global value chains (GVCs) on greenhouse gas (GHG) emissions. The integrated effects of TP depend on the positioning of sectors in GVCs. The cost-saving TP in upstream sectors would stimulate downstream demand. This produces stronger rebound effects than mitigation potentials and leads to global GHG emission increments (e.g. TP in the gas sector of China and petroleum and coal products sector of South Korea). In contrast, sectors located in the trailing end of GVCs have greater potentials for GHG emission mitigation through TP, mainly due to the reduction of upstream inputs. (e.g. the construction sector of China and dwelling sector of the United States). Global GHG emissions and production outputs can be either a trade-off or a win-win relationship on account of TP than rebound effects, because TP in different sectors could possibly increase or decrease the emission intensity of GVCs. This study could recognize the most productive spots for GHG emission mitigation through efficiency-related TP. It provides a new perspective for international cooperation to promote global GHG emission mitigation.

Consumption in Non-Pastoral Regions Drove Three-Quarters of Forage-Livestock Conflicts in China.

Forage-livestock conflict (FLC) is a major anthropogenic cause of rangeland degradation. It poses tremendous threats to the environment owing to its adverse impacts on carbon sequestration, water supply and regulation, and biodiversity conservation. Existing policy interventions focus on the in situ FLCs induced by local production activities but overlook the role of consumption activities in driving FLCs. Here, we investigate the spatiotemporal variations in China's FLCs and the domestic final consumers at the county level by combining remote sensing data and multi-regional input-output model. Results show that during 2005-2015, China's pastoralism induced an average of 82 million tons of FLCs per year. Domestic final demand was responsible for 85-93% of the FLCs in China. There was spatiotemporal heterogeneity in domestic consumption driving China's FLCs. In particular, the final demand of non-pastoral regions was responsible for around three-quarters (74-79%) of the total FLCs throughout the decade. The rangeland-based livestock raising, agricultural and sideline product processing, and catering sectors are important demand-side drivers. These findings can support targeted demand-side strategies and interregional cooperation to reduce China's FLCs, thus mitigating rangeland degradation.

Cascading impacts of global metal mining on climate change and human health caused by COVID-19 pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has significantly disrupted global metal mining and associated supply chains. Here we analyse the cascading effects of the metal mining disruption associated with the COVID-19 pandemic on the economy, climate change, and human health. We find that the pandemic reduced global metal mining by 10-20% in 2020. This reduction subsequently led to losses in global economic output of approximately 117 billion US dollars, reduced CO2 emissions by approximately 33 million tonnes (exceeding Hungary's emissions in 2015), and reduced human health damage by 78,192 disability-adjusted life years. In particular, copper and iron mining made the most significant contribution to these effects. China and rest-of-the-world America were the most affected. The cascading effects of the metal mining disruption associated with the pandemic on the economy, climate change, and human health should be simultaneously considered in designing green economic stimulus policies.

A high spatial resolution dataset for anthropogenic atmospheric mercury emissions in China during 1998-2014.

China is the largest atmospheric mercury (Hg) emitter globally, which has been substantially investigated. However, the estimation of national or regional Hg emissions in China is insufficient in supporting emission control, as the location of the sources may have significant impacts on the effects of Hg emissions. In this concern, high-spatial-resolution datasets of China's Hg emissions are necessary for in-depth and accurate Hg-related studies and policymaking. Existing gridded datasets are constructed using population distribution as the proxy, which is limited as Hg emissions are closely related to energy consumption and economic processes. This study constructs a dataset of anthropogenic atmospheric Hg emissions in China gridded to a 1 km resolution during 1998-2014. This dataset is produced based on data of land uses, individual enterprises, roadmaps, and population, uncovering Hg emissions in agriculture, industries, services, and residents. This dataset can promote the reliability of Hg-related studies at a high spatial resolution. Moreover, this dataset can support spatially explicit Hg reduction of economic sectors.

Human health and ecosystem impacts of China's resource extraction.

The throughput of materials fuels the economic process and underpins social well-being. These materials eventually return to the environment as waste or emissions. They can have significant environmental impacts throughout life cycle stages, such as biodiversity loss, adverse health effects, water stress, and climate change. China is the largest resource extractor globally, but the endpoint environmental impacts and the role of possible socioeconomic drivers associated with its resource extraction remain unclear. Here, we account for and analyze the two endpoint environmental impacts associated with China's resource extraction from 2000 to 2017 and quantify the relative contributions of various socioeconomic factors using structural decomposition analysis. The results show that the environmental impacts of China's resource extraction peaked in 2010. There was a significant decline from 2010 to 2017, in which human health damage decreased by 32.8 % and ecosystem quality damage decreased by 55.8 %. On the consumer side, the advancement in China's urbanization process led to an increase in the environmental impacts of urban residents' consumption, and the effect of investment on the environmental impacts decreased significantly after 2010. Decreases in the intensity of the environmental impacts in most sectors and improvements in production structure could reduce the impacts of resource extraction on human health and ecosystems.

Global Supply Chain Drivers of Agricultural Antibiotic Emissions in China.

Antibiotic pollution causes serious environmental and social issues. China is the largest antibiotic producer and user in the world, with a large share of antibiotics used in agriculture. This study quantified agricultural antibiotic emissions of mainland China in 2014 as well as critical drivers in global supply chains. Results show that China's agriculture discharged 4131 tons of antibiotics. Critical domestic supply chain drivers are mainly located in Central China, North China, and East China. Foreign final demand contributes 9% of agricultural antibiotic emissions in mainland China and leads to 5-40% of emissions in each province. Foreign primary inputs (e.g., labor and capital) contribute 5% of agricultural antibiotic emissions in mainland China and lead to 2-63% of emissions in each province. Critical international drivers include the final demand of the United States and Japan for foods and textile products, as well as the primary inputs of the oil seeds sector in Brazil. The results indicate the uniqueness of supply chain drivers for antibiotic emissions compared with other emissions. Our findings reveal supply chain hotspots for multiple-perspective policy decisions to control China's agricultural antibiotic emissions as well as for international cooperation.

Sustainability performance of global chemical industry based on green total factor productivity.

The sustainability of the chemical industry is crucial for achieving global sustainable production. The sustainability performance of global chemical industry is influenced by many issues synergistically and has not been fully quantified. Systematic analysis from multiple perspectives, such as resource savings, economic growth, and environmental improvement, is urgently needed to support effective macro-policy decisions. This study quantifies the variation trend of the sustainability of the global chemical industry during 2004-2014 and identifies the driving forces under the framework of green total factor productivity (GTFP). Results show that most developed countries performed efficiently (with GTFP values equal to 1) in sustainable production of the chemical industry, while the least developed countries usually performed inefficiently (with GTFP values lower than 1). Notably, a polarization of sustainability in the chemical industry has been confirmed among countries with different production capacities. From 2004 to 2014, the sustainability performance of the global chemical industry has generally improved. It was mainly driven by technological progress (resulting from independent technological innovation) rather than efficiency catching-up (derived from technological learning). Furthermore, technological progress was manifested mainly as the improvement in CO2 reduction performance and capital saving performance, while technological learning was manifested mainly as the improvement in labor saving performance. Based on the conclusions of this study, the international world is suggested to take action to strengthen international technology cooperation, and governments should make prioritized and focused policies to effectively promote the sustainability of global chemical industry.

Role of Trade in India's Rising Atmospheric Mercury Emissions.

India is among the largest emitters of atmospheric mercury (Hg) in the world. India's production activities have associated Hg emissions which can be attributed to final demands (e.g., purchases by households, governments, and private investments) of nations driving upstream production from the demand perspective, or primary inputs (e.g., labor and capital supply) of nations enabling downstream production from the supply perspective. This study identifies key nations and sectors that directly and indirectly drove India's Hg emissions from both the demand and supply perspectives during 2004-2014. While domestic final demand was the dominant driver from the demand perspective (driving about 80-85% of the total), USA, China, and UAE are important foreign drivers. Similarly, from the supply perspective, domestic primary inputs were the dominant drivers. However, the share of foreign inputs enabling Hg emissions increased from 16 to 23% during the decade. Saudi Arabia, Indonesia, Australia, and China are the top foreign supply-side drivers. The Construction sector is an important demand-side driver, whereas fossil fuel sectors are important supply-side drivers. These findings can guide global and national policies for demand- and supply-side management of Hg emissions in India and assist in the successful implementation of the Minamata Convention on Mercury.

Life cycle assessment and society willingness to pay indexes of food waste-to-energy strategies.

Food waste (FW) has received increasing attention because of its immense production quantities and significance to resource and environmental impacts related to disposal approaches. We combined life cycle assessment (LCA) with society's willingness to pay (WTP) index to evaluate energy, water, and environmental impacts on three food waste-to-energy (FWTE) options in China. For anaerobic digestion (AD) mode, the results showed that 1140 MJ of energy consumption could be saved by power generation from methane, power transmission, and biodiesel production from per ton of FW; the cost of climate change for treating FW was 137.8 kg CO2e t-1 FW, failing to be climate-sound due to the end life of digestate in practice. The total impact to AD mode in the form of monetized value for WTP was 13.3 CNY t-1 FW, of which the collection and transportation, pretreatment, AD reaction, wastewater treatment, biodiesel production, and residue landfilling stages contributed by 10.5%, 6.5%, 19.3%, 27.6%, 4.7%, and 75.7%, respectively, while biogas utilization offset it by 43.9%. Notably, a considerable amount of water used in AD prevented it from showing an advantage compared to incineration (-5.1 CNY t-1 FW), which performed best overall attributing to the generated electricity compensated for primary energy demand, water, and terrestrial acidification to a great extent. Landfilling turned out to be an unappealing FW disposal method due to the low landfill gas capture ratio. Given that AD is touted for its environmental benefits, potential approaches-such as developing a reliable and supportive technology to facilitate digestate recycling into agriculture-were discussed to improve its competitiveness and attractiveness. Our study employed a way to accumulate and compare impact indicators to better interpret FW management impacts and advantages, considering energy recovery, resource recycling, and the environment.

Planetary Boundaries for Forests and Their National Exceedance.

Achieving forest sustainability is a declared sustainable development goal (SDG 15). Measuring the safe operating space─planetary boundaries─of global forests is essential to determine global forest pressure and manage forests sustainably. Here, we quantify the forestry planetary boundary (FPB) and national forestry boundaries. Results show that, in 2015, the FPB was 7.1 billion m3 of forest stock increments. Global timber harvests account for 58.7% of the FPB. Timber harvests of 47 nations, mostly in Africa and Asia, have exceeded their national forestry boundaries. Their boundary-exceeding timber harvest is mainly driven by the final demand of developed nations (e.g., the United States and Japan) and emerging economies (e.g., India and China) through global supply chains. This study highlights the importance of the FPB in global forest management and trade-related policymaking. The findings can guide global and national forest harvesting activities and help promote international cooperation to mitigate global deforestation.

Urban Food Systems: A Bibliometric Review from 1991 to 2020.

The increase of urbanization is affecting the urban food system (UFS) in many areas, primarily production, processing, and consumption. The upgrading of the urban food consumption structure not only puts forward higher food production requirements, but also poses a challenge to resource consumption and technological innovation. Considerable case or review studies have been conducted on UFS, but there is no bibliometric review attempting to provide an objective and comprehensive analysis of the existing articles. In this study, we selected 5360 research publications from the core Web of Science collection from 1991 to 2020, analyzing contributions of countries, institutions, and journals. In addition, based on keyword co-occurrence and clustering analyses, we evaluated the research hotspots of UFS. The results show that global research interest in UFS has increased significantly during these three decades. The USA, China, and the UK are the countries with the highest output and closest collaborations. UFS research involves multiple subject categories, with environmental disciplines becoming mainstream. Food security, food consumption, and food waste are the three main research areas. We suggest that food sustainability and resilience, food innovation, and comparative studies between cities should be given more attention in the future.