Coupling and coordinated evolution characteristics of regional economy-energy-carbon emission multiple systems: A case study of main China's Basin.

Comprehensive analysis of the Economy-Energy-Carbon Emission (EECE) system is beneficial for promoting sustainable social development. This study analyzes the system development of major watersheds in China from 2010 to 2019. The research fully considers the system's internal and external inputs and outputs and proposes an evaluation index system for regional EECE coupling and coordinated development. Then, using the difference in system weight allocation to improve the coupling and coordination model, the study explores the dynamic system's coupling and coordination. The results show that (1) The development of the system structure is relatively stable, but the overall development status is not ideal; (2) The downstream of China's main river basins has obvious economic advantages, while the energy system fluctuates greatly. The efficiency of the carbon emission system will decrease in areas with rapid economic development. The coupling and coordination level of the EECE system is better in the Yangtze River Basin than in the Yellow River Basin; (3) From the perspective of dynamic coordinated development, the main river basins have been divided into two states since 2012, but it is relatively stable overall. Regional dynamic coordination is often at a disadvantage in regions with rapid economic and energy development; (4) The coupling coordination degree of the two river basins has significant positive spatial autocorrelation. Most provinces' significant spatial clustering characteristics of the coupling coordination degree are High-High type. Low-Low type provinces are mainly concentrated downstream. The research process has certain reference significance for the collaborative governance of complex regional systems.

Scenario analysis of the eco-efficiency for municipal solid waste management: A case study of 211 cities in western China.

Mitigating greenhouse gas (GHG) emissions is vital for creating sustainable municipal solid waste management systems (MSWMS). In this study, we constructed an MSWMS considering recycling and carried out GHG emission accounting for MSWMS in western China from 2012 to 2021 based on the IPCC mass balance (MB) method. Then, we modeled the emission reduction potentials and economic benefits under different scenarios for 211 prefectural and county-level cities. We formed an eco-efficiency analysis framework that can be used to explore the sustainable development mode. Results revealed that: (1) Emissions from the western region's municipal solid waste (MSW) disposal exhibit an inverted "U" pattern, increasing at an annual rate of about 1.3 % since 2012, peaking in 2019, and then decreasing at rates of 14.4 % and 10.6 %. (2) The GHG emissions show a spatial pattern of decreasing evolution from east to west and south to north, and the provincial-municipal level shows different trends. (3) The SB3 scenario (optimization of landfill gas power generation technology) was the most ecologically efficient in 43 % of the western cities, followed by SB4 (33 %) and SA3 (24 %). (4) The development of integrated urban domestic waste management strategies by the three-level scenarios derived from this study will help local governments achieve the goal of sustainable urban development. Clarifying the differences in GHG emissions and eco-efficiency among cities will help provide policy recommendations for regions with similar characteristics to explore technically applicable, economically affordable implementation paths for city management according to local conditions.

Assessment of cobalt recycling potential and environmental impact in China from 1994 to 2020.

Cobalt recycling is important for solving environmental problems such as resource shortage and pollution emissions. This paper quantifies the positive significance of cobalt recycling on resource replenishment and pollution emission by using the substance flow analysis and life cycle analysis. The results show that the proportion of recycled cobalt supplied as cobalt raw material is 7.1%, which improves the supply structure of the resource. Meanwhile, the environmental impact of recycling cobalt using the combined treatment process is low. The environmental impact of mining cobalt from mines is about 4.03-41.53 times that of recycling cobalt from cobaltiferous waste materials. However, the overall cobalt recycling is not ideal. First, the cobalt recycling rate is growing slowly. From 1994 to 2020, 245,132 t of cobalt-containing final products entered waste management in China. However, only 79,593 t of cobalt have been recycled, with a recycling rate of 32.47%. Secondly, many recycling enterprises only carry out recycling for a certain type of cobaltiferous waste materials due to the non-uniform cobalt recycling process. Finally, China's cobalt recycling policy does not divide the recycling channels for cobalt waste and does not regulate the specific process. In the future, China should set up separate recycling systems for cobaltiferous waste materials according to different categories and consider adopting combined treatment processes. China can only promote the sustainable use of cobalt if it ensures stable and orderly cobalt recycling in terms of policy and technology.

Trends and status in resources security, ecological stability, and sustainable development research: a systematic analysis.

Resources are essential for human survival and development, and resource security occupies an important position in national security. With the increasing resource shortage problem, ecological stability is facing severe challenges. All countries are actively seeking new sustainable development ways to deal with various issues and shocks caused by the shortage of resources. This study aims to systematically and comprehensively evaluate the knowledge structure, research hotspots, and resource security evolution trends. Based on the number of 6391 articles retrieved from the Web of Science database from 1990 to 2021, this article carried out a visual analysis of global resource security research from the perspectives of scientific output characteristics, keywords, and highly cited literature scientific collaboration networks and hotspot emergence analysis. The research results show that after humans have experienced new public safety incidents, their understanding of resource security and sustainable development has risen to a new height. The number of relevant documents is increasing rapidly. At present, the research on resource security is still dominated by developed countries in Europe and America. This study finds that "food supply chain," "water availability," and "soil resources suitability" are the frontiers and hotspots in the field of resource security. Besides, "biodiversity," "mineral resource security," "medical and health resources" are important topics and directions of current research. This study provides a theoretical basis for scholars to explore the future research direction and practice of resource security, to achieve ecological stability and sustainable development.

Research trend and dynamical development of focusing on the global critical metals: a bibliometric analysis during 1991-2020.

Critical metals are indispensable to a world seeking to transition away from carbon. Yet their extraction, processing, and application leave an unsustainable global environment and climate change footprint. To capture the development dynamics and research emphases of critical metals throughout their life cycle, this paper adopts bibliometrics to analyze the various stages of global critical metal flow in multiple dimensions to reveal the hot issues and future strategic trends. The research results indicate that the number of research papers on critical metals is annually rising, with remarkably rapid growth after 2010. Judging from the number of articles published by the authors and the citations, among the authors, Kawakita, Poettgen, Anwander, Inoue, and Dongmei Cui have a significant influence on critical metal research fields. The institutions with the most research on critical metals are universities, not research institutes. In addition, the focus has extended from a single discipline to the interdisciplinary development of multiple disciplines. Analysis of keywords shows that "rare metals" and "precious metals" are the most popular metals among the researched metals. The researched buzzwords of critical metals are disappearing, convergent, and merging over time. The research has focused on the mining and the whole life cycle process of extraction, treatment, and application. Based on the above characteristics, this paper tries to understand the dynamic development and evolution of global critical metals from multiple dimensions, resorting to giving a reference for follow-up-related research scholars.

Carbon emission of energy consumption of the electric vehicle development scenario.

To explore the impact of promotion of electric vehicles on carbon emissions in China, this paper used the principal component analysis (PCA)-logistic regression model to predict the demand for traditional vehicles, and used the scenario analysis method to analyze the proportion of electric vehicles in traditional vehicles qualitatively. Then this paper calculated the carbon emissions during the power generation process based on the existing power structure. In addition, the IPCC carbon emission calculation method is used to compare the CO2 emissions produced by electric vehicles and fuel vehicles with similar vehicle quality while driving the same distance and consuming different energy sources. The results showed that the CO2 emissions of electric vehicles accounted for only 37.05% of fuel vehicles. By 2050, the annual electricity demand of electric vehicles will be 828.7, 776.9, and 752.1 billion kWh under the radical scenario, the reference scenario, and the negative scenario, respectively. According to the current power structure, the carbon emissions will be 1.2, 1.1, and 1 billion tons, respectively. The rapid growth of electric vehicles has a substantial impact on the grid load. Studying the changes in CO2 emissions from energy substitution is significant to formulate the development strategy of the automobile industry and adjust energy structure policies.

Energy conservation and carbon reduction potential for solid waste in China.

The generation of solid waste has increased dramatically in China, owing largely to the rapid development and expansion of the Chinese economy. The management of solid waste is critical and becoming a challenge for some cities in China. Waste recycling is an effective solution to solid waste management and seeks to balance ecological sustainability with economic improvements. This study assessed the energy conservation and CO2 emission reduction potential of solid waste using an embodied energy/carbon model from a life cycle perspective. The results showed that compared with the production of virgin materials, solid waste recycling results in a reduction of 294.2 Mtce in energy consumption, and 614.5 Mt in CO2 emission is shown in 2017. The recycling of steel waste was the highest contributor, accounting for more than 45% of energy conservation and at least 62% of CO2 reduction. If 100% recycling of recyclable waste like steel waste and plastic waste can be achieved, energy conservation and CO2 reduction could reach 551.89 Mtce and 933.69 Mt, respectively, accounting for 12.29% of energy consumption and 8.46% of CO2 emission. A robust recycling system must be established to achieve the purpose of environment production and resource conservation. The proposed evaluation framework could help in the decision-making process. The waste classification must be promoted to increase waste recovery rate and improve waste reproduction technology to maximize energy conservation and CO2 emission reduction.

A Scientometric Analysis of Global Health Research.

With the development and deepening of the process of global integration, global health is gaining increasing attention. An increasing number of studies have examined global health from diverse perspectives to promote the realization of global public health. The purpose of this research is to systematically and comprehensively evaluate the knowledge structure, knowledge domain, and evolution trend in the field of global health research. Based on the 14,692 document data retrieved from Web of Science Core Collection from 1996 to 2019, this article carried out a visual analysis of global health research from the perspective of scientific output characteristics, scientific research cooperation networks, keywords, and highly cited literature. The results show that scholars' interest in global health research is increasing, especially after the outbreak of SARS. USA, England, Canada, Australia, and China have the most prominent contributions to global health research. Significant authors, high impact journals and core institutions also identified. The study found that "global health governance", "global health diplomacy", "medical education", "global health education" and "antimicrobial resistance" are the research frontiers and hot spots. This study provides an overview and valuable guidance for researchers and related personnel to find the research direction and practice of global health.

Environmental Pollution Effect Analysis of Lead Compounds in China Based on Life Cycle.

Environmental pollution caused by lead toxicity causes harm to human health. Lead pollution in the environment mainly comes from the processes of mining, processing, production, use, and recovery of lead. China is the world's largest producer and consumer of refined lead. In this paper, the material flow analysis method is used to analyze the flow and direction of lead loss in four stages of lead production, manufacturing, use, and waste management in China from 1949 to 2017. The proportion coefficient of lead compounds in each stage of lead loss was determined. The categories and quantities of lead compounds discharged in each stage were calculated. The results show that in 2017, China emitted 2.1519 million tons of lead compounds. In the four stages of production, manufacturing, use, and waste management, 137.9 kilo tons, 209 kilo tons, 275 kilo tons, and 1.53 million tons were respectively discharged. The emissions in the production stage are PbS, PbO, PbSO4, PbO2, Pb2O3, and more. The emissions during the manufacturing phase are Pb, PbO, PbSO4, Pb2O3, Pb3O4, and more. The main emissions are Pb, PbO, Pb2O3, Pb3O4, and more. The main emissions in the waste management stage are PbS, Pb, PbO, PbSO4, PbO2, PbCO3, Pb2O3, Pb3O4, and more. Among them, the emissions of PbSO4, PbO, Pb, and PbO2 account for about 90%, which are the main environmental pollution emissions. The waste management stage is an important control source of lead compound emission and pollution. In view of these characteristics of the environmental pollution risk of lead compounds in China, the government should issue more targeted policies to control lead pollution.

A Scientometric Review of Resource Recycling Industry.

With rapid economic development and urbanization, a large number of primary resources are consumed and accumulate in society as recyclable resource, which causes great pressure on the environment. The development of the resource recycling industry (RRI) can reduce environmental impacts and achieve sustainable development and green growth. Scholars are paying more attention to the resource recycling industry (RRI), and the related literature continues to increase. There are over 7041 publications covering RRI in the Web of Science database from 1996 to 2018. This paper analyzes the time distribution characteristics of the literature and the status of the scientific research cooperation network using the visualization analysis software CiteSpace. The number of documents increased from 94 in 1996 to a peak of 963 in 2018. There is no relatively stable core author group. The number of papers published by "Chinese Acad Sci" ranks first among all research institutions. Document co-citation analysis and burst detection are adopted to assess the status and emerging trends in the RRI research domain. A publication by M.C. Monte on waste management is the most cited paper. Additionally, "green and sustainable and technology" and "science and technology-other topics" are the latest emerging subject categories in RRI research. Furthermore, "e-waste", "reverse logistics" and "lean manufacturing" are emerging research trends for RRI, and "carbon emissions", "policy", "demolition waste", "supply chain management" and "compressive strength" have become hot topics. These findings may provide inspiration for scholars to search for new research directions and ideas.