• Energy Research
• 8. Economic growth close
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Abstract The rapid economic development of China has been accompanied by the emission of a great number of pollutants, which in turn have caused severe environmental problems. To strengthen environmental management and to establish a pollution source information database covering all key pollution sources and activities, China carried out its first National Census of Pollution Sources (NCPS) in 2007. The survey contents include the basic environmental situation in 2007, the generation levels of the main pollutants at that time, and the amount of pollution actually discharged into the environment after end-of-pipe treatment at all kinds of pollution sources. Based on the first NCPS report for China released in 2011, and taking two typical industry pollutants, sulfur dioxide (SO 2 ), and chemical oxygen demand (COD) as examples, we first revised the historical data concerning environmental statistics based on the NCPS documents. Subsequently, we analyzed the overall industrial scale in the change of SO 2 and COD emissions using index decomposition analysis, and then studied the contributions and comparative significance of the “three pollution emission reduction measures” put forward by the Chinese government. The latter are: Engineering Emission Reduction (EER), Structure Emission Reduction (SrER) and Supervision Emission Reduction (SuER). From these analyses, we were able to identify the main driving forces for SO 2 and COD emission reduction in China's industrial system. The results indicate that, with continually increasing pollution pressure caused by rapid economic development, EER and SuER have made the greatest contributions to reducing SO 2 and COD emissions; but SrER has not had an obvious effect. In the future, EER and SuER will gradually have less and less potential and become more challenging, while SrER should be achievable through adjusting the economic structure.

River deltas and estuaries are disproportionally-significant coastal landforms that are inhabited by nearly 600 M people globally. In recent history, rapid socio-economic development has dramatically changed many of the World's mega deltas, which have typically undergone agricultural intensification and expansion, land-use change, urbanization, water resources engineering and exploitation of natural resources. As a result, mega deltas have evolved into complex and potentially vulnerable socio-ecological systems with unique threats and coping capabilities. The goal of this research was to establish a holistic understanding of threats, resilience, and adaptation for four mega deltas of variable geography and levels of socio-economic development, namely the Mekong, Yellow River, Yangtze, and Rhine deltas. Compiling this kind of information is critical for managing and developing these complex coastal areas sustainably but is typically hindered by a lack of consistent quantitative data across the ecological, social and economic sectors. To overcome this limitation, we adopted a qualitative approach, where delta characteristics across all sectors were assessed through systematic expert surveys. This approach enabled us to generate a comparative assessment of threats, resilience, and resilience-strengthening adaptation across the four deltas. Our assessment provides novel insights into the various components that dominate the overall risk situation in each delta and, for the first time, illustrates how each of these components differ across the four mega deltas. As such, our findings can guide a more detailed, sector specific, risk assessment or assist in better targeting the implementation of risk mitigation and adaptation strategies.

As issues concerning “circular economy” and “sustainable development” have been advocated globally, the recycling, reuse, recovery or disposal of end-of-life vehicles (ELVs) have gained more and more attention. Toxic substances and wasted resources within ELVs make evaluating the sustainability of ELV recycling enterprises to be especially important for sound ELV management. In this study, an improved emergy analysis with traditional and revised emergy indices was employed for evaluation of the efficiency and sustainability of ELV recycling enterprises. The constructed emergy indicator system not only reflected the ELV recycling system's resource, environmental, economic and technological efficiency, but also made a multi-scale and multi-dimensional evaluation of the system according to its industrial characteristics. An ELV recycling enterprise in Jiangxi Province, China, as a case, was studied employing the proposed method and indicator system. The results showed that the enterprise involved in the study had strong competitive ability with relatively high economic benefit, and had a moderate environmental impact compared with other industrial systems. The emergy sustainability index indicated that the recycling enterprise was both economically and environmentally sustainable in the long term. However, the emergy technical efficiency indices indicated that the technical level and operational efficiency of the ELV recycling enterprise were relatively low and more investment should be put into the improvement of the recycling technologies. The results of the study can provide useful information for the decision makers to manage ELV recycling enterprises considering not only economic benefits but also the environmental benefits in the long term.

Improving energy efficiency is regarded as a key path to tackling global warming and achieving the Sustainable Development Goals (SDGs). In 2020, the energy consumption of the world's ten major energy-consuming countries accounted for 66.8% of the global total. This paper applied data envelopment analysis (DEA) to calculate these ten major energy-consuming countries' total-factor energy efficiency (TFEE) at national and sectoral levels from 2001-2020, and explored the influencing factors of total-factor energy efficiency with the Tobit regression model. The results showed significant difference in the ten countries' energy efficiency. The United States and Germany topped the list for total-factor energy efficiency, while China and India were at the bottom. Meanwhile, the energy efficiency of the industrial subsector has increased significantly over the past two decades, while that of the other subsectors has been relatively flat. The industrial structure upgrading, per capita GDP, energy consumption structure, and foreign direct investment had significant impacts on energy efficiency with national heterogeneity. Energy consumption structure and GDP per capita were determinative factors of energy efficiency.

Plants acquire carbon through photosynthesis to sustain biomass production, autotrophic respiration and production of non-structural compounds for multiple purposes. The fraction of photosynthetic production used for biomass production, the biomass production efficiency, is a key determinant of the conversion of solar energy to biomass. In forest ecosystems, biomass production efficiency was suggested to be related to site fertility. Here we present a database of biomass production efficiency from 131 sites compiled from individual studies using harvest, biometric, eddy covariance, or process-based model estimates of production. The database is global, but dominated by data from Europe and North America. We show that instead of site fertility, ecosystem management is the key factor that controls biomass production efficiency in terrestrial ecosystems. In addition, in natural forests, grasslands, tundra, boreal peatlands and marshes, biomass production efficiency is independent of vegetation, environmental and climatic drivers. This similarity of biomass production efficiency across natural ecosystem types suggests that the ratio of biomass production to gross primary productivity is constant across natural ecosystems. We suggest that plant adaptation results in similar growth efficiency in high- and low-fertility natural systems, but that nutrient influxes under managed conditions favour a shift to carbon investment from the belowground flux of non-structural compounds to aboveground biomass.

Abstract The primary problem in achieving carbon emission reduction and carbon peak is to identify the key driving factors and emission reduction potential of the industrial sector, especially in resource-cursed regions like Xinjiang. This study aimed to explore the key driving factors and abatement potential of carbon emissions based on the "energy-environment-economy" hybrid input-output model of Xinjiang during 1997-2017. The result showed that: (1)Industrial carbon emissions have experienced three stages: slow growth-rapid growth-stable growth. (2)Demand change effect and energy intensity effect were the determinants of industrial carbon emission change; Capital formation and domestic trade were the biggest drivers of carbon emissions growth, and the driving force of imports in international trade increased gradually over time. (3) The coal-based energy structure was both the biggest obstacle and the best entry point in carbon emission reduction. (4) Of the 28 key industry sectors, heavy industry including the production and supply of electricity and heat (S22), petroleum processing, coking and nuclear fuel processing (S11), chemical industry (S12), metal smelting and rolling (S14), and energy industries had the greatest potential for carbon reduction. The research findings provide scientific decision-making reference for Xinjiang to accurately grasp the carbon emission reduction potential of the industry and formulate a targeted carbon peak action plan.

Abstract One of the greatest problems in using renewable energy sources is the great variability of energy level, both in the short and long term. Geothermal energy, by nature, has high availability because the source is not dependent on weather conditions, so it is among the most stable renewable energy sources. In China, urban populations are provided with their electricity requirements, but rural areas need guaranteed electricity for socio-economic development. Fortunately, mid-low temperature geothermal resources are located proximal to rural areas without access to grid electricity in China. Small-scale geothermal power plants can support electricity demand as well as create employment opportunities for the rural public. Therefore, geothermal energy has the potential to play an important role in the future energy supply of China. Based on mid-low temperature geothermal resource and waste heat resource, the paper introduces the energy efficiency of single-flash and binary cycle geothermal power plant. The result shows that binary cycle plant is favorable for power generation when water temperature is below 130 °C, otherwise, flash steam power plant is a better choice. Furthermore, two project cases were analyzed in the end, focusing on the operating parameters and thermal efficiency. The single-flash and binary cycle geothermal power plants could be improved energy efficiency of low-grade resources and both widely utilized in China.