Search

It is vital to find reasons for differences in the results of environmental input-output (EIO), physical input-output (PIO), and hybrid input-output (HIO) models for industrial and environmental policy analysis. Using EIO, PIO, and HIO models, China's industrial metabolism is calculated. Four reasons were found to account for differences in the results of analysis using EIO, PIO, and HIO models: the manner in which they deal with residential consumption, service sectors, and waste recycling, and the assumption of unique sector prices. The HIO model, which treats residential consumption as sectors of the intermediate delivery matrix, is preferred to the EIO and PIO models for analyzing industrial and environmental policies. Moreover, waste recycling in five sectors-agriculture; the manufacture of paper, printing, and articles for culture, education, and sports activities; the manufacture of nonmetallic mineral products; smelting and pressing of metals; and construction-should be comprehensively considered when using the HIO model to study problems related to these five sectors. Improvements in the EIO, PIO, and HIO models and future work are also discussed. [ABSTRACT FROM AUTHOR]

The relative risk model (RRM) was applied to evaluate the ecological risk characterization of the freshwater ecosystems in China, from both overall and region-specific levels. Ten large-scale river basins (further broken into 15 risk regions) in China were chosen as the study objects; 10 sources, two habitats, and seven endpoints were identified as risk components. The results reveal the status of ecosystem conditions, key ecological risk issues, and the spatial heterogeneity of the freshwater ecosystems in China. The policy implications for the ecosystem-based water management contained in the results are discussed. The results obtained in this article provide a deeper understanding of the ecological risk characterization of the freshwater ecosystems in China, and aid in promoting the applications of the RRM as the tool for ecosystem-based water management. [ABSTRACT FROM PUBLISHER]

Abstract: Sustainable urban materials management is significant for environmental sustainability. This study identifies key economic sectors for sustainable urban materials management using urban physical input–output (PIOT) table and hierarchical cluster analysis method to mitigate urban air pollutants (comprising CO2, SO2 and NO x ) and examines uncertainties. Suzhou city in China is taken as an example. Key economic sectors in Suzhou considering direct amount are production and supply of electric and heat power, smelting and pressing of ferrous metals, services, other manufacturing, textile, non-metallic mineral products and chemistry, while key economic sectors considering accumulative amount are agriculture, construction, production and supply of electric and heat power, services and smelting and pressing of ferrous metals. Uncertainties for sustainable urban materials management are consistent with the development stage of the economy. Thus, when constructing urban PIOT for a particular city based on monetary input–output table (MIOT) of another city or province, the development stage of the city or province whose MIOT is used should be similar to that of the particular city. If not, lower and upper limits for the development stage should be set to investigate uncertainties. [Copyright &y& Elsevier]

Abstract: Investigating impacts of urban solid waste recycling on urban metabolism contributes to sustainable urban solid waste management and urban sustainability. Using a physical input–output model and scenario analysis, urban metabolism of Suzhou in 2015 is predicted and impacts of four categories of solid waste recycling on urban metabolism are illustrated: scrap tire recycling, food waste recycling, fly ash recycling and sludge recycling. Sludge recycling has positive effects on reducing all material flows. Thus, sludge recycling for biogas is regarded as an accepted method. Moreover, technical levels of scrap tire recycling and food waste recycling should be improved to produce positive effects on reducing more material flows. Fly ash recycling for cement production has negative effects on reducing all material flows except solid wastes. Thus, other fly ash utilization methods should be exploited. In addition, the utilization and treatment of secondary wastes from food waste recycling and sludge recycling should be concerned. [Copyright &y& Elsevier]

Rapid global urbanization has caused substantial changes in land cover and vegetation growth. Rapid urban growth in a short time has escalated the conflicts between economic development and ecological conservation, particularly in some metropolitan regions. However, the effects of rapid urbanization on vegetation have not been fully captured, especially accounting for the latest ecological development initiatives. In this study, we chose a typical urban agglomeration, the Beijing–Tianjin–Hebei (BTH) urban agglomeration in China, and analyzed the vegetation variation and the impacts of urbanization on the vegetation growth based on transferable methods, using data such as the Normalized Difference Vegetation Index (NDVI) and the nighttime light (NTL). The results indicate significantly enhanced vegetation growth in the BTH region, with a strikingly spatial pattern of greening in the northwest, and browning in the southeast from 2001 to 2018. Besides this, the results enclose most of the areas (72%) of built-up land in the BTH, which tended to brown in the process of rapid urban development, while 27% greened with increasing urbanization. This means that the vegetation's response to urbanization shows apparent differences and geographic heterogeneity along the urbanization gradient at the urban agglomeration scale. Parts of the periphery of the metropolis and the central areas of developing cities may experience a browning trend; however, the core urban areas of urbanized metropolises demonstrate greening, rather than browning. Furthermore, this study provides solid evidence on the remarkable greening impacts of several ecological restoration projects which are currently underway, especially in ecologically fragile areas (e.g., the suburbs). The implications derived from the urban ecological development and the transferable methodology deployed in this paper facilitate the unfolding relationships between urbanization and social-ecological development. Our findings provide new insights into the interactions between vegetation dynamics and urbanization at the regional level. [ABSTRACT FROM AUTHOR]

The physical input-output (PIO) model has different product flow scopes from the monetary input-output (MIO) model. Using the PIO and MIO models to analyze the structure of material flows can identify new hotspots for policy decisions over each other. However, PIO models are not well-studied in existing studies on the structure of China's material flows. This study uses both the PIO and MIO models to analyze consumption-based material flows of Chinese sectors and critical supply chain paths leading to China's material flows. Results show that the PIO and MIO models validate each other by simultaneously identifying critical sectors and important final demand categories. However, product prices and the treatment of services lead to different findings based on the MIO and PIO models. Compared with the PIO model, the MIO model underestimates the contribution of the construction sector to China's material flows, but overestimates that of the equipment and machinery and other services sectors. The PIO model reveals the higher importance of rural household consumption, while the MIO model identifies more critical supply chain paths associated with services. The PIO and MIO models can complement each other in the implementation and assessment of environmental measures (e.g., production efficiency improvement). [ABSTRACT FROM AUTHOR]

Abstract: This study proposed a novel way for global greenhouse gas reduction through reusing China’s waste oil to produce biofuels. Life cycle greenhouse gas mitigation potential of aviation bio-kerosene and biodiesel derived from China’s waste oil in 2010 was equivalent to approximately 28.8% and 14.7% of mitigation achievements on fossil-based CO2 emissions by Annex B countries of the Kyoto Protocol in the period of 1990–2008, respectively. China’s potential of producing biodiesel from waste oil in 2010 was equivalent to approximately 7.4% of China’s fossil-based diesel usage in terms of energy. Potential of aviation bio-kerosene derived from waste oil could provide about 43.5% of China’s aviation fuel demand in terms of energy. Sectors key to waste oil generation are identified from both production and consumption perspectives. Measures such as technology innovation, government supervision for waste oil collection and financial subsidies should be introduced to solve bottlenecks. [Copyright &y& Elsevier]

Abstract: With China’s rapid economic development and urbanization process, cities are facing great challenges for tackling anthropogenic climate change. In this paper we present features, trajectories and driving forces for energy-related greenhouse gas (GHG) emissions from four Chinese mega-cities (Beijing, Tianjin, Shanghai and Chongqing) during 1995–2009. First, top-down GHG inventories of these four cities, including direct emissions (scope 1) and emissions from imported electricity (scope 2) are presented. Then, the driving forces for the GHG emission changes are uncovered by adopting a time serial LMDI decomposition analysis. Results indicate that annual GHG emission in these four cities exceeds more than 500 million tons and such an amount is still rapidly growing. GHG emissions are mainly generated from energy use in industrial sector and coal-burning thermal power plants. The growth of GHG emissions in four mega-cities during 1995–2009 is mainly due to economic activity effect, partially offset by improvements in carbon intensity. Besides, the proportion of indirect GHG emission from imported energy use (scope 2) keeps growing, implying that big cities are further dependent on energy/material supplies from neighboring regions. Therefore, a comprehensive consideration on various perspectives is needed so that different stakeholders can better understand their responsibilities on reducing total GHG emissions. [Copyright &y& Elsevier]