The anthropogenic cycles of palladium in China during 2001-2020.

Palladium (Pd) is a strategic metal and can help reduce environmental pollution, especially from vehicle exhausts. China is the world's largest Pd consumer, but with very limited reserves. However, Pd anthropogenic cycles remain unclear in China. This study aims to uncover the dynamic Pd flows and stocks in China for the period of 2001-2020 by conducting dynamic material flow analysis. The results show that the demand for Pd had increased by 10 folds during the study period due to stricter vehicle emissions policies. Also, China mainly imported such resource from the United States, Western Europe, and East Asia, with a share of 88.8 %. However, due to insufficient end-of-life vehicle (ELV) recycling system, the total recycled Pd was only 12.3 tons although the end-of-life Pd flow increased from 3.7 tons in 2001 to 30.8 tons in 2020. This implies a great Pd recycling potential. Therefore, it is urgent to promote Pd recycling by establishing an effective Pd recycling system. In addition, other policy recommendations, such as diversifying Pd import partners, increasing Pd emergency reserves, and economic instruments, are raised by considering the Chinese realities so that the overall Pd resource efficiency can be improved.

The global power sector's low-carbon transition may enhance sustainable development goal achievement.

The low-carbon power transition, which is key to combatting climate change, has far-reaching effects on achieving the Sustainable Development Goals (SDGs) in terms of issues such as resource use, environmental emissions, employment, and many more. Here, we assess the potential impacts of the power transition on progress toward achieving multiple SDGs (covering 18 targets across the 17 goals) across 49 economies under nine socioeconomic and climate scenarios. We find that the low-carbon power transition under the representative concentration pathway (RCP)2.6 scenarios could lead to an approximately 11% improvement in the global SDG index score from 54.70 in 2015 to 59.89-61.33 in 2100. However, the improvement would be significantly decreased to 4.42%-7.40% and 7.55%-8.93% under the RCP6.0 and RCP4.5 scenarios, respectively. The power transition could improve the overall SDG index in most developed economies under all scenarios while undermining their resource-related SDG scores. Power transition-induced changes in international trade would improve the SDG progress of developed economies but jeopardize that of developing economies, which usually serve as resource hubs for meeting the demand for low-carbon power transition in developed economies.

Impacts of Trans-Provincial Thermal Power Transmission on Air-Quality Recovery and Related Health Outcomes in China.

Trans-provincial thermal power transmission has become an important measure for optimizing power allocation and alleviating the mismatch between regional power production and consumption in China, however, leading to inter-regional redistribution of air pollution. Here, we investigated the impacts of thermal power transmission on air-quality recovery and related health outcomes in China. The results showed that the redistribution of air pollutant emissions contributed to air-quality improvements and health benefits in the eastern regions but to the opposite side in the western regions. On a national scale, trans-provincial thermal power transmission contributed to a change in air quality from slightly polluted to good conditions for a period of 9 days under the standard of 75 µg m-3, accounting for 1.8% of the total number of polluted days in 4 months of 2017 and promoting air-quality recovery in China. Furthermore, the recovery totally reduced the number of premature deaths (exposed to fine particulate matter, PM2.5) by 2392 persons (95% confidence interval: 1495-3124) in 2017. Owing to thermal power retrofits and stable power transmission structure, transmission network expansion during the last decade has not brought significant changes in its impacts on air pollution. However, the environmental inequity caused by thermal power transmission stimulates further attention on coordinating regional interests in air pollution control through various production-side and consumption-side measures.

Measuring the anthropogenic cycles of light rare earths in China: Implications for the imbalance problem.

Light rare earth elements (LREEs) are of strategic importance for low carbon transition and decarbonization. However, the imbalance between LREEs exists and a systematic understanding of their flows and stocks is lacking, which impedes the attainment of resources efficiency and exacerbates the environmental burdens. This study examines the anthropogenic cycles and the imbalance problem of three representative LREEs in China, the largest LREEs producer in the world, including cerium (the most abundant), neodymium and praseodymium (the fastest demand-growing). We find that 1) from 2011 to 2020, the total consumption of Nd and Pr increased by 228 % and 223 %, respectively, mainly attributed to the increasing demand of NdFeB, whereas that of Ce increased by 157 %; 2) the supply insufficiency of Nd and Pr under the current quota system accumulated to 138,086 tons and 35,549 tons, respectively, while the oversupply of Ce reached 63,523 tons; and 3) China has become a net importer of LREEs concentrates, and a net exporter of LREEs in the form of intermediate and final products, imposing further burdens to the domestic environment. It is clear that the imbalance of LREEs occurred during the study period, raising urgent needs to adjust the LREEs production quotas, seek other Ce applications, and eliminate illegal mining.

How does digital technology promote carbon emission reduction? Empirical evidence based on e-commerce pilot city policy in China.

Digital technology is an effective way to realize the carbon neutrality target in China. Therefore, based on panel data at the city level in China from 2006 to 2016, we take the e-commerce pilot policy as a quasi-natural experiment, using the staggered difference-in-differences (DID) method to explore the effect of digital technology development on carbon emissions and its transmission mechanism. The conclusion of this paper shows that (ⅰ) the e-commerce pilot policy has significantly reduced carbon emissions. After a series of robustness tests, this empirical conclusion is still valid. (ⅱ) The inhibitory effect of different waves of e-commerce pilot cities on carbon emissions sequentially decreases. The e-commerce pilot policy has a greater effect on reducing carbon emissions in non-old industrial based cities and non-resource-based cities. (ⅲ) Implementing the e-commerce pilot city policy mainly reduces urban carbon emissions by optimizing resource allocation, reducing energy consumption and upgrading the industrial structure. (ⅳ) In addition, implementing the e-commerce pilot city policy has a significant positive carbon-reducing linkage effect with the carbon trading pilot policy and the low-carbon city pilot policy. The findings of this paper provide empirical evidence for carbon emission reduction, which has implications for upgrading urban construction patterns and promoting green urban development.

The spatial-temporal evolution mechanism of PM2.5 concentration based on China's climate zoning.

Increasing attention has been given to the impact of PM2.5 concentration on human health. Exploring the influential factors of PM2.5 is conducive to improving air quality. Most existing studies explore the factors that influence the PM2.5 concentration from the perspective of cities or urban agglomerations, while few studies are conducted from the perspective of climate zones. We used the standard deviation ellipse and spatial autocorrelation analysis to explore the spatial-temporal evolution of the PM2.5 concentration in different climate zones in China during 2000-2018. We used differentiated EKC to construct panel regression models to explore the differences in the influential factors of the PM2.5 concentration in three climate zones. The number of cities with PM2.5 concentration less than 35 µg/m3 increased in the different climate zones. The center of gravity of the PM2.5 concentration has remained at the junction of the temperate and subtropical monsoon climate zones. The PM2.5 concentration had a high positive spatial autocorrelation in the different climate zones. The high-high clustering areas were located in the south of the temperate monsoon climate zone and the north of the subtropical monsoon climate zone. There was an inverted "U-shaped" curve between the PM2.5 concentration and economic development in China that varied in different climate zones. Identifying the differences in the influential factors of PM2.5 concentration in different climate zones will help to accelerate the implementation of the EKC inflection point.

Sustainable social development promotes COVID-19 pandemic control.

The rapid spread of COVID-19 had a negative impact on public health and economic recovery worldwide. There is a large and growing literature on pandemic prevention and control. However, these existing studies seldom focus on the role of sustainable social development in this process. By setting specifications of fixed-effect models based on the score data of sustainable development goals (SDG) and infection case data from 257 Chinese cities, we evaluate the positive effect of sustainable social development on pandemic control. Our results show that sustainable social development leads to a remarkable improvement in pandemic prevention and control, especially for SDG4 (Quality Education) and SDG5 (Gender Equality). Significant positive effects of sustainable social development still exist in the post-pandemic era. This study highlights the importance of promoting social SDGs by linking them with pandemic prevention and control and suggests region-specific policies based on the heterogeneous analysis results.

China industrial environmental database 1998-2015.

There has been a rapid-growing trend in studying China's environmental problems in the past decade. However, the existing environmental statistics data are far from meeting researchers' requirements. The biggest problem is that the official environmental statistics data are only provided at either regional level or sectoral level. Considering the huge heterogeneities in different regions and sectors, researchers are unable to conduct comprehensive policy evaluations. In this study, we constructed the time-series industrial environmental database for China (CIED) at both regional and sectoral level. The database includes totally 31 regions and four types of pollutants: chemical oxygen demand (COD), sulphur dioxide (SO2), ammonia-nitrogen (NH3-N), and nitrogen oxide (NOX). This study also clarifies several important concepts for researchers to better understand China's official environmental statistics data.

Import competition and the improvement in pollutant discharge from heterogeneous enterprises: Evidence from China.

With the deepening of trade liberalization, import competition has become increasingly fierce in China. In addition, the Chinese government has been setting higher requirements for environmental quality. Corporate pollutant emission behavior is a subject of broad concern. This paper uses panel data from 2000 to 2007 to study the impact of import competition on the pollution emission intensity of heterogeneous manufacturing enterprises. The main results are as follows. (1) Import competition can inhibit the SO2 emission intensity of high-productivity manufacturing enterprises. The conclusion remains robust after a series of robustness tests. (2) Heterogeneity analysis shows that import competition significantly impacts corporate pollution emission behavior in eastern regions and frontier industries. (3) The reallocation effect and the technology effect are the main channels through which import competition improves the pollution emissions of high-productivity manufacturing enterprises. This paper provides a more comprehensive perspective for studying the impact of import competition and proposes a new direction for enterprise pollution control.

Increasing mercury risk of fly ash generated from coal-fired power plants in China.

The trend in mercury (Hg) content of fly ash, the primary solid Hg waste from coal-fired power plants (CFPPs), has not been well evaluated in China. This study integrated a national sampling campaign, a literature survey, and model predictions to investigate the trend in Hg content of fly ash and associated output nationwide. The results demonstrated that Hg content of fly ash from both our campaign conducted in 2020 and the literature survey met the Weibull distribution. The best estimate for the distribution of Hg content in our campaign (401.4 µg/kg) was about two-fold higher than that from the literature survey (236.6 µg/kg). The increasing trend was mainly attributed to the increasing installation of advanced air pollution control devices (APCDs) in CFPPs. The total national Hg output by fly ash was estimated to be 217.7 tons (64.1-501.8 tons) currently. Regarding the disposal of fly ash, a total of 16.1 tons and 105.8 tons of Hg were re-emitted into the air and immobilized in materials, respectively. The increasing trend in the Hg content of fly ash suggested the need for more stringent requirements for the disposal of solid Hg waste from CFPPs in China.

Chinese provincial multi-regional input-output database for 2012, 2015, and 2017.

Global production fragmentation generates indirect socioeconomic and environmental impacts throughout its expanded supply chains. The multi-regional input-output model (MRIO) is a tool commonly used to trace the supply chain and understand spillover effects across regions, but often cannot be applied due to data unavailability, especially at the sub-national level. Here, we present MRIO tables for 2012, 2015, and 2017 for 31 provinces of mainland China in 42 economic sectors. We employ hybrid methods to construct the MRIO tables according to the available data for each year. The dataset is the consistent China MRIO table collection to reveal the evolution of regional supply chains in China's recent economic transition. The dataset illustrates the consistent evolution of China's regional supply chain and its economic structure before the 2018 US-Sino trade war. The dataset can be further applied as a benchmark in a wide range of in-depth studies of production and consumption structures across industries and regions.

Decomposing the decoupling of plastics consumption and economic growth in G7 and China: Evidence from 2001 to 2020 based on China's import ban.

Plastic recycling is critical for dematerializing of plastics. It has a profound implication on decoupling economic growth from environmental pressure and advancing waste plastic governance domestically and internationally while identifying drivers that might improve decoupling. In this study, plastic consumption and recycling patterns are presented, and the factors influencing the acceleration of dematerialization subsequent to the ban were investigated in the G7 countries and China. The results show that plastic consumption increases from 7.60 million metric tons (mt) to 12.60 mt between 2017 and 2019, and subsequently rapidly decreases to 6.84 mt in 2020. The plastic recycling rate drastically decreased by 21.3% in 2017, and decreased slightly from 2017 to 2020, at an annual rate of 2.9% on average. China's ban shocked the decoupling trends, which showed resilience and motivated the development of robust plastic recycling, and the global recycling transformation pattern accelerated the dematerialization of plastics. Decoupling performances of the G7 and China gradually stabilized in 2019, and all the countries were strongly decoupled in 2020, although decoupling index (DI) fluctuates from 2017 to 2020. Among the recycling-trading drivers, the improvement of waste plastic quality in recycling contributes more to decoupling, the recycling rate shows a more negative decoupling effect on China before the ban, and the population effect is weak relative to other influencing factors. The factors revealed the mechanism of decoupling of plastic consumption in the recycling-trading process, and the recyclability improvement in terms of plastic quality is important for dematerialization.

The reallocation effect of China's provincial power transmission and trade on regional heavy metal emissions.

Coal-fired power plants (CFPPs) are key point sources to atmospheric heavy metal (HM) emissions in China. Unevenly distributed CFPPs lead to large-scale interregional power transmission, as well as corresponding environmental emissions transfer. However, the effect of power transmission on HM reallocation remains poorly understood. Here, we traced HM (including Hg, As, Se, Pb, Cd, and Cr) emission flows through electricity transmission and regional trade and calculated China's multi-perspective electricity-related HM emissions from 2010 to 2015. Results show that in 2015, power transmission and regional trade caused 226.5 t (14% of total emissions) and 453.6 t (28%) of HM emission flows, respectively, leading to great differences in provincial HM emissions under different perspectives (e.g., Beijing's consumption-based emission was 15.5 times higher than the city's production-based emission in 2015). Our study provides valuable insights for fairly allocating provincial HM emission reduction responsibility and formulating synergistic emission mitigation strategies among regions.

The effect of economic growth target constraints on green technology innovation.

According to data from the working reports of China's 244 prefecture-level city governments from 2004 to 2016, we used the instrumental variable method to identify the effects of governments' behavior of setting economic growth targets on regional green technology innovation. The results show that the setting and top-down amplification of economic growth targets have significant inhibitory effects on green technology innovation. The inhibitory effect is more prominent in cities with rapid economic growth and over fulfilment of economic growth targets. In addition, the higher the degree of over fulfilment of the economic target becomes, the more prominent the inhibiting effect is. An impact mechanism analysis reveals that economic growth target constraints affect regional green technology innovation through an industrial structure effect and foreign investment introduction effect.

Study of the emissions and spatial distributions of various power-generation technologies in China.

The power sector is the main contributor to climate change and atmospheric pollution, and reducing the emissions from the power sector is essential for achieving sustainable development. However, few studies have accounted for the emissions from various power-generation technologies. In this paper, a high-resolution inventory of power plants with more than 6 MW accounting for 93% of the national power generation in China is established for the first time. Based on this inventory, the CO2, NOx and SO2 emissions of China's hard coal power, natural gas power, hydropower, wind power, photovoltaic power, biomass power and nuclear power are calculated by using the life cycle assessment method, and their spatial distributions in 2014 are further analyzed. The results show that China's power plants emitted 3.44 E+09 t CO2, 8.56 E+06 t NOx, and 1.19 E+07 t SO2, and the uncertainties were (-18.66%, +19.14%), (-67.10%, +66.41%) and (-88.69%, +87.61%) in 2014, respectively. Renewable-energy power plants accounted for approximately 15% of the national power generation but only contributed less than 1% of the total emissions. Meanwhile, in China's eastern cities, renewable-energy power accounts for the lowest proportion of the total installed capacity. In addition, both the emission amount and intensity were significantly higher in eastern cities than central and western cities. This study will help improve research on the emissions of all power-generation technologies in China and help achieve a comprehensive and systematic emissions reduction strategy.

Using Existing Infrastructure to Realize Low-Cost and Flexible Photovoltaic Power Generation in Areas with High-Power Demand in China.

This study develops a new concept involving using the existing infrastructure for photovoltaic (PV) generation to reduce the costs associated with increased land use and to avoid curtailment due to the mismatch between power supply and demand. We establish a method to estimate the technological potential and economic performance of the PV systems deployed in coal-fired power plants in China. The potential capacity of the examined 1,082 units in China reaches 4 GWe, which is equivalent to 32% of China's newly installed distributed PV capacity in 2019. A total of 87% of PV systems achieve plant-side grid parity compared with desulfurized coal benchmark electricity prices. To the best of our knowledge, this is the first study that investigates the use of rooftops and coal storage sheds in power plants to facilitate low-cost, flexible PV power generation, thus opening a new channel for future PV generation development.

A 2015 inventory of embodied carbon emissions for Chinese power transmission infrastructure projects.

The spatial mismatch of energy resources and electricity demand in China drives the large-scale construction of power transmission infrastructure, which consumes a large amount of carbon-intensive products. However, a systematic accounting framework for the carbon emissions of power transmission infrastructure has not yet been established. This study for the first time compiles an embodied carbon emissions inventory covering 191 typical power transmission infrastructure projects in China in 2015, including 145 types of alternating current (AC) transmission line projects, 37 typical AC substation projects, 8 typical direct current (DC) transmission line projects and 1 typical DC converter station project. The inventory also shows the detailed inputs of all the projects. These data not only enable a quantitative assessment of the embodied carbon emissions of power transmission infrastructure in China but also provide essential information for climate mitigation policy design in the power sector.

Unbalanced economic benefits and the electricity-related carbon emissions embodied in China's interprovincial trade.

Quantifying the economic benefits and environmental costs brought about by trade can help reveal the environmental inequalities behind regional trade. There have been many studies on the accounting of greenhouse gas emissions and pollutants embodied in regional trade, but there are insufficient studies analyzing the imbalance between the economic benefits and environmental costs embodied in trade. Electricity-related carbon emissions are the main contributor to global warming, explaining more than 40% of carbon emissions both globally and in China. This study uses the network approach and multiregional input-output (MRIO) model to quantify the electricity-related carbon emissions and value added embodied in China's interprovincial trade from 2007 to 2012 and also applies the regional environmental inequality (REI) index to measure the imbalance of electricity-related carbon emissions and economic benefits embodied in such trade. The results show that 20-80% of the electricity-related carbon emissions and 15-70% of the value added of a province's final demand are outsourced to other provinces. The major directions of the net value added and electricity-related carbon emissions embodied in China's interprovincial trade were from north to south and from the center to the east. Unequal bilateral interprovincial trade mainly occurred between inland provinces and developed provinces, and western provinces (such as Guizhou, Gansu, and Ningxia) suffered economic and environmental losses from interprovincial trade. This study can promote understanding of the distribution impacts of domestic trade on environmental costs and economic benefits and provide a reference for China's cross-provincial carbon emission mitigation policies.

Social inequality among elderly individuals caused by climate change: Evidence from the migratory elderly of mainland China.

Faced with severe and growing social inequality among elderly individuals, a more complete understanding of the interconnection between the seasonal migration of the elderly and climate change is clearly needed. This paper tries to clarify the relation between the seasonal migration of the elderly and climate change from a multidimensional perspective. Our study adds to the research on population aging against the background of climate change. This study shows that climate change has a significant impact on regional population aging and that there are significant internal differences between the distribution and scale of the migratory elderly stemming from unequal environmental conditions. Advanced economic conditions and relatively comfortable environments have put some pressure on social endowment services in the three provinces of Northeast China, especially Liaoning Province. With their complex migration mechanism, the fate of the elderly in mainland China is closely intertwined with climatic factors, individual and socioeconomic conditions, traditional cultural backgrounds, etc. A comparatively advanced economy, well-developed endowment resources, and a comfortable environment will help in the development of regional aging resources. Regional inequality and the pursuit of a meaningful life have created different categories of migratory elderly.