This paper analyzes current urban symbiosis development and application in China, and then conducts a statistical analysis of the emissions reduction of CO2 and CH_4 in relation to recovery of iron and steel scraps, w...This paper analyzes current urban symbiosis development and application in China, and then conducts a statistical analysis of the emissions reduction of CO2 and CH_4 in relation to recovery of iron and steel scraps, waste paper, and waste plastics from 2011 to 2014 using the greenhouse gas(GHG) emission inventory calculation method provided by the IPCC. Results indicate that the cumulative recovery of renewable resources during China's main urban symbiosis development in 2011e2014 was 803.275 Mt, and the amount of iron and steel scraps, waste paper, and waste plastic recovery was the largest, respectively accounting for 62.2%, 18.0%, and 8.2% of total recovery in 2014. In addition, the cumulative emissions reduction of GHGs in relation to recovery of iron and steel scraps, waste paper, and waste plastics in 2011e2014 was27.962 Mt CO_2-eq, 954.695 Mt CO_2-eq, and 22.502 Mt CO_2-eq, respectively, thereby totaling 1005.159 Mt CO_2-eq. Results show a remarkable GHG emissions reduction during 2011e2014.展开更多
China’s aluminum(Al)production has released a huge amount of greenhouse gas(GHG)emissions.As one of the biggest country of primary Al production,China must mitigate its overall GHG emission from its Al industry so th...China’s aluminum(Al)production has released a huge amount of greenhouse gas(GHG)emissions.As one of the biggest country of primary Al production,China must mitigate its overall GHG emission from its Al industry so that the national carbon neutrality target can be achieved.Under such a background,the study described in this paper conducts a dynamic material flow analysis to reveal the spatiotemporal evolution features of Al flows in China from 2000 to 2020.Decomposition analysis is also performed to uncover the driving factors of GHG emission generated from the Al industry.The major findings include the fact that China’s primary Al production center has transferred to the western region;the primary Al smelting and carbon anode consumption are the most carbonintensive processes in the Al life cycle;the accumulative GHG emission from electricity accounts for 78.14% of the total GHG emission generated from the Al industry;China’s current Al recycling ratio is low although the corresponding GHG emission can be reduced by 93.73% if all the primary Al can be replaced by secondary Al;and the total GHG emission can be reduced by 88.58% if major primary Al manufacturing firms are transferred from Inner Mongolia to Yunnan.Based upon these findings and considering regional disparity,several policy implications are proposed,including promotion of secondary Al production,support of clean electricity penetration,and relocation of the Al industry.展开更多
Earth’s magnetopause is a thin boundary separating the shocked solar wind plasma from the magnetospheric plasmas,and it is also the boundary of the solar wind energy transport to the magnetosphere.Soft X-ray imaging ...Earth’s magnetopause is a thin boundary separating the shocked solar wind plasma from the magnetospheric plasmas,and it is also the boundary of the solar wind energy transport to the magnetosphere.Soft X-ray imaging allows investigation of the large-scale magnetopause by providing a two-dimensional(2-D)global view from a satellite.By performing 3-D global hybrid-particle-in-cell(hybrid-PIC)simulations,we obtain soft X-ray images of Earth’s magnetopause under different solar wind conditions,such as different plasma densities and directions of the southward interplanetary magnetic field.In all cases,magnetic reconnection occurs at low latitude magnetopause.The soft X-ray images observed by a hypothetical satellite are shown,with all of the following identified:the boundary of the magnetopause,the cusps,and the magnetosheath.Local X-ray emissivity in the magnetosheath is characterized by large amplitude fluctuations(up to 160%);however,the maximum line-of-sight-integrated X-ray intensity matches the tangent directions of the magnetopause well,indicating that these fluctuations have limited impact on identifying the magnetopause boundary in the X-ray images.Moreover,the magnetopause boundary can be identified using multiple viewing geometries.We also find that solar wind conditions have little effect on the magnetopause identification.The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will provide X-ray images of the magnetopause for the first time,and our global hybrid-PIC simulation results can help better understand the 2-D X-ray images of the magnetopause from a 3-D perspective,with particle kinetic effects considered.展开更多
China removed fertilizer manufacturing subsidies from 2015 to 2018 to bolster market-oriented reforms and foster environmentally sustainable practices.However,the impact of this policy reform on food security and the ...China removed fertilizer manufacturing subsidies from 2015 to 2018 to bolster market-oriented reforms and foster environmentally sustainable practices.However,the impact of this policy reform on food security and the environment remains inadequately evaluated.Moreover,although green and low-carbon technologies offer environmental advantages,their widespread adoption is hindered by prohibitively high costs.This study analyzes the impact of removing fertilizer manufacturing subsidies and explores the potential feasibility of redirecting fertilizer manufacturing subsidies to invest in the diffusion of these technologies.Utilizing the China Agricultural University Agri-food Systems model,we analyzed the potential for achieving mutually beneficial outcomes regarding food security and environmental sustainability.The findings indicate that removing fertilizer manufacturing subsidies has reduced greenhouse gas(GHG)emissions from agricultural activities by 3.88 million metric tons,with minimal impact on food production.Redirecting fertilizer manufacturing subsidies to invest in green and low-carbon technologies,including slow and controlled-release fertilizer,organic-inorganic compound fertilizers,and machine deep placement of fertilizer,emerges as a strategy to concurrently curtail GHG emissions,ensure food security,and secure robust economic returns.Finally,we propose a comprehensive set of government interventions,including subsidies,field guidance,and improved extension systems,to promote the widespread adoption of these technologies.展开更多
Solar wind charge exchange produces emissions in the soft X-ray energy range which can enable the study of near-Earth space regions such as the magnetopause,the magnetosheath and the polar cusps by remote sensing tech...Solar wind charge exchange produces emissions in the soft X-ray energy range which can enable the study of near-Earth space regions such as the magnetopause,the magnetosheath and the polar cusps by remote sensing techniques.The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)and Lunar Environment heliospheric X-ray Imager(LEXI)missions aim to obtain soft Xray images of near-Earth space thanks to their Soft X-ray Imager(SXI)instruments.While earlier modeling works have already simulated soft X-ray images as might be obtained by SMILE SXI during its mission,the numerical models used so far are all based on the magnetohydrodynamics description of the space plasma.To investigate the possible signatures of ion-kinetic-scale processes in soft Xray images,we use for the first time a global hybrid-Vlasov simulation of the geospace from the Vlasiator model.The simulation is driven by fast and tenuous solar wind conditions and purely southward interplanetary magnetic field.We first produce global X-ray images of the dayside near-Earth space by placing a virtual imaging satellite at two different locations,providing meridional and equatorial views.We then analyze regional features present in the images and show that they correspond to signatures in soft X-ray emissions of mirrormode wave structures in the magnetosheath and flux transfer events(FTEs)at the magnetopause.Our results suggest that,although the time scales associated with the motion of those transient phenomena will likely be significantly smaller than the integration time of the SMILE and LEXI imagers,mirror-mode structures and FTEs can cumulatively produce detectable signatures in the soft X-ray images.For instance,a local increase by 30%in the proton density at the dayside magnetopause resulting from the transit of multiple FTEs leads to a 12%enhancement in the line-of-sight-and time-integrated soft X-ray emissivity originating from this region.Likewise,a proton density increase by 14%in the magnetosheath associated with mirror-mode structures can result in an enhancement in the soft X-ray signal by 4%.These are likely conservative estimates,given that the solar wind conditions used in the Vlasiator run can be expected to generate weaker soft X-ray emissions than the more common denser solar wind.These results will contribute to the preparatory work for the SMILE and LEXI missions by providing the community with quantitative estimates of the effects of small-scale,transient phenomena occurring on the dayside.展开更多
In recent years,the United Arab Emirates(UAE)has developed strategies to increase renewable power generation and reduce emis-sions to net zero by 2050.Electricity generation and energy-intensive industries(EII)have th...In recent years,the United Arab Emirates(UAE)has developed strategies to increase renewable power generation and reduce emis-sions to net zero by 2050.Electricity generation and energy-intensive industries(EII)have the largest potentials for emission reduc-tion.Therefore,an up-to-date inventory of greenhouse gas emissions and a study of the pathways to achieving the 2050 targets are essential.This study focuses on power production and EII(aluminium,steel and cement).The structure of these sectors is modelled and simulated up to 2050 using a system dynamics(SD)methodology.The SD model is validated to reflect the real-world state of the system using the emissions inventory projections as reference modes.Nineteen mitigation policies are considered in the selected sectors and four policy scenarios were simulated.The results show that implementing the Energy Strategy 2050 in the power sector can result in a reduction of 63.5%in emissions in that sector,which translates into a reduction of 33.5%overall by 2050.Additionally,implementing all identified mitigation strategies to full utilization in EII yields a 94%reduction in that sector,which translates into a 78%reduction overall.Decarbonizing the aluminium industry yields the highest emissions reductions,followed by power produc-tion,then cement and finally steel.In the best-case scenario,22.1%of the business-as-usual emissions are still released and further decarbonization—mainly in the power sector—will be required.This is achievable given the trajectory of the UAE’s successful nuclear energy programme and the prospect of utilizing carbon capture,utilization and storage even further.展开更多
The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this sector.In this paper,international environmental governance in the steel indu...The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this sector.In this paper,international environmental governance in the steel industry is reviewed,and the current state of development of low-carbon technologies is discussed.Additionally,low-carbon pathways for the steel industry at the current time are proposed,emphasizing prevention and treatment strategies.Furthermore,the prospects of low-carbon technologies are explored from the perspective of transitioning the energy structure to a“carbon-electricity-hydrogen”relationship.Overall,steel enterprises should adopt hydrogen-rich metallurgical technologies that are compatible with current needs and process flows in the short term,based on the carbon substitution with hydrogen(prevention)and the CCU(CO_(2) capture and utilization)concepts(treatment).Additionally,the capture and utilization of CO_(2) for steelmaking,which can assist in achieving short-term emission reduction targets but is not a long-term solution,is discussed.In conclusion,in the long term,the carbon metallurgical process should be gradually supplanted by a hydrogen-electric synergistic approach,thus transforming the energy structure of existing steelmaking processes and attaining near-zero carbon emission steelmaking technology.展开更多
This paper analyzes the key indicators of the impact assessment the teleworking as practice of performing regular work from home or from a location close to home,on reducing the number of travel and reduced carbon emi...This paper analyzes the key indicators of the impact assessment the teleworking as practice of performing regular work from home or from a location close to home,on reducing the number of travel and reduced carbon emissions transportation activities.Models and methodologies described in the literature are a good basis for a better and more comprehensive and understanding of the positives and negative effects teleworking and real opportunities of its wider application,however there is a lack of systemic analysis.Development of a set of indicators for assessing emission reduction induced by the measures to promote sustainable transport.Due to the complexity of the transport sector,a change in any indicator models have side effects on other indicators(unwanted and multiplier effects)and what is the theme of our research work.展开更多
The process-oriented model Forest-DNDC describing biogeochemical cycling of C and N and GHGs (greenhouse gases) fluxes (CO2, NO and N2O) in forest ecosystems was applied to simulate carbon sequestration and GHGs emiss...The process-oriented model Forest-DNDC describing biogeochemical cycling of C and N and GHGs (greenhouse gases) fluxes (CO2, NO and N2O) in forest ecosystems was applied to simulate carbon sequestration and GHGs emissions in Abies fabric forest of the Gongga Mountains at southeastern edge of the Tibetan Plateau. The results indicated that the simulated gross primary production (GPP) of Abies fabric forest was strongly affected by temperature. The annual total GPP was 24,245.3 kg C ha-1 yr-1 for 2005 and 26,318.8 kg C ha-1 yr-1 for 2006, respectively. The annual total net primary production (NPP) was 5,935.5 and 4,882.2 kg C ha-1 yr-1 for 2005 and 2006, and the annual total net ecosystem production (NEP) was 4,815.4 and 3,512.8 kg C ha-1 yr-1 for 2005 and 2006, respectively. The simulated seasonal variation in CO2 emissions generally followed the seasonal variations in temperature and precipitation. The annual total CO2 emissions were 3,109.0 and 4,821.0 kg C ha-1 yr-1 for 2005 and 2006, the simulated annual total N2O emissions from forest soil were 1.47 and 1.36 kg N ha-1 yr-1 for 2005 and 2006, and the annual total NO emissions were 0.09 and 0.12 kg N ha-1 yr-1 for 2005 and 2006, respectively.展开更多
Abies fabric forest in the eastern slope of Gongga mountain is one type of subalpine dark coniferous forests of southwestern China. It is located on the southeastern edge of the Qinghai-Tibet plateau and is sensitive ...Abies fabric forest in the eastern slope of Gongga mountain is one type of subalpine dark coniferous forests of southwestern China. It is located on the southeastern edge of the Qinghai-Tibet plateau and is sensitive to climatic changes. A process-oriented biogeochemical model, Forest-DNDC, was applied to simulate the effects of climatic factors, temperature and precipitation changes on carbon characteristics, and greenhouse gases (GHGs) emissions in A. fabric forest. Validation indicated that the Forest-DNDC could be used to predict carbon characteristics and GHGs emissions with reasonable accuracy. The model simulated carbon fluxes, soil carbon dynamics, soil CO2, N2O, and NO emissions with the changes of temperature and precipitation conditions. The results showed that with variation in the baseline temperature from -2℃to +2℃, the gross primary production (GPP) and soil organic carbon (SOC) increased, and the net primary production (NPP) and net ecosystem production (NEP) decreased because of higher respiration rate. With increasing baseline precipitation the GPP and NPP increased slightly, and the NEP and SOC showed decreasing trend. Soil CO2 emissions increased with the increase of temperature, and CO2 emissions changed little with increased baseline precipitation. With increased temperature and decreased baseline temperature, the total annual soil N2O emissions increased. With the variation of baseline temperature from -2℃to +2℃, the total annual soil NO emissions increased. The total annual N2O and NO emissions showed increasing trends with the increase of precipitation. The biogeochemical simulation of the typical forest indicated that temperature changes strongly affected carbon fluxes, soil carbon dynamics, and soil GHGs emissions. The precipitation was not a principal factor affecting carbon fluxes, soil carbon dynamics, and soil CO2 emissions, but changes in precipitation could exert strong effect on soil N2O and NO emissions.展开更多
This study was performed to estimate the emission of non-CO 2 greenhouse gases(GHGs) from biomass burning at a large fire area.The extended methodology adopted the IPCC Guidelines(2003) equation for use on data from t...This study was performed to estimate the emission of non-CO 2 greenhouse gases(GHGs) from biomass burning at a large fire area.The extended methodology adopted the IPCC Guidelines(2003) equation for use on data from the Samcheok forest fire gathered using 30 m resolution Landsat TM satellite imagery,digital forest type maps,and growing stock information per hectare by forest type in 1999.Normalized burn ratio(NBR) technique was employed to analyze the area and severity of the Samcheok forest fire that occurred in 2000.The differences between NBR from pre-and post-fire datasets are examined to determine the extent and degree of change detected from burning.The results of burn severity analysis by dNBR of the Samcheok forest fire area revealed that a total of 16,200 ha of forest were burned.The proportion of the area characterized by a 'Low' burn severity(dNBR below 152) was 35%,with 'Moderate'(dNBR 153-190) and 'High'(dNBR 191-255) areas were at 33% and 32%,respectively.The combustion efficiency for burn severity was calculated as 0.43 for crown fire where burn severity was 'High',as 0.40 for 'Moderate' severity,and 0.15 for 'Low' severity surface fire.The emission factors for estimating non-CO 2 GHGs were separately applied to CO 130,CH 4 9,NO x 0.7 and N 2 O 0.11.Non-CO 2 GHGs emissions from biomass burning in the Samcheok forest fire area were estimated to be CO 44.100,CH 4 3.053,NO x 0.238 and N 2 O 0.038 Gg.展开更多
In recent years,China has implemented several measures to improve air quality.The Beijing-Tianjin-Hebei(BTH)region is one area that has suffered from the most serious air pollution in China and has undergone huge chan...In recent years,China has implemented several measures to improve air quality.The Beijing-Tianjin-Hebei(BTH)region is one area that has suffered from the most serious air pollution in China and has undergone huge changes in air quality in the past few years.How to scientifically assess these change processes remain the key issue in further improving the air quality over this region in the future.To evaluate the changes in major air pollutant emissions over this region,this paper employs ensemble Kalman filtering(EnKF)for integrating the national ground monitoring pollutant observation data and the Nested Air Quality Prediction Modeling System(NAQPMS)simulation data to inversely estimate the emission rates of SO_(2),NOX,CO,and primary PM_(2.5)over BTH region in February from 2014 to 2019.The results show that SO_(2),NOX,CO,and primary PM_(2.5)emissions in the BTH region decreased in February from 2014 to 2019 by 83%,37%,41%,and 42%,while decreases in Beijing during this period were 86%,67%,59%,and 65%,respectively.Compared with the prior emission inventory,the inversion emission inventory reduces the uncertainty of multi-pollutant simulation in the BTH region,with simulated root mean square errors of the monthly average concentrations of SO_(2),NOX,PM_(2.5),and CO reduced by 41%,30%,31%,and 22%,respectively.The average uncertainties of SO_(2),NOX,PM_(2.5),and CO inversion emissions in2014-19 are±14.03%yr^(-1),±28.91%yr^(-1),±126.15%yr^(-1),and±43.58%yr^(-1).Compared with the uncertainty of MEIC emission,the uncertainties of all species changed by+2%yr^(-1),-2%yr^(-1),-26%yr^(-1),and-4%yr^(-1),respectively.The spatial distribution results illustrate that air pollutant emissions are mainly distributed over the eastern and southern BTH regions.The spatial gap between the inversion emissions and MEIC emissions was further closed in 2019 compared to 2014.The results of this paper can provide a new reference for assessing changes in air pollution emissions over the BTH region in recent years and validating a bottom-up emission inventory.展开更多
The Asia-Pacific Economic Cooperation(APEC)is contemplating expanding its list of environmental goods(EG)for trade liberalization to fight climate change.In support of doing so,this study proposes that a long list tha...The Asia-Pacific Economic Cooperation(APEC)is contemplating expanding its list of environmental goods(EG)for trade liberalization to fight climate change.In support of doing so,this study proposes that a long list that retains controversies is better for carbon emission reduction than a short common list.This study examines four mechanisms of longer lists:enlarging market scales,enriching product mixes,enhancing product sophistication,and enriching trade patterns.Using China’s emerging EG trade during the 2001-2015 period as a case study,this study compares four EG lists with different EG.The results show that:(1)a longer list reduces carbon emissions from both imports and exports,making domestic regions with different advantages have better chances of improving carbon efficiencies.(2)Product sophistication reduces the emission gap between trading partners,regardless of the length of EG lists.(3)China’s EG exports contribute to carbon reduction in leading regions,while EG imports provide laggard regions with better chances of reducing carbon emissions.These findings provide three implications for future list-making:it is important to(1)seek a long and inclusive list rather than a short common list,(2)shift the focus from environmental end-use to the technological contents of products,and(3)balance the demand of laggard regions to import and the capacity of leading regions to export.展开更多
The current study extends the previous literature by exploring the effects of a newly discovered driver,i.e.,import taxes(as a proxy for commercial policies),on the consumption-based carbon emissions(CCO2e)for 1990Q1-...The current study extends the previous literature by exploring the effects of a newly discovered driver,i.e.,import taxes(as a proxy for commercial policies),on the consumption-based carbon emissions(CCO2e)for 1990Q1-2017Q4.For empirical analysis,several tests and methods,including Augmented Dickey–Fuller unit root test,Zivot–Andrews unit root test,asymmetric cointegration bound testing approach,non-linear ARDL,Wald-test,Granger causality test and wavelet quantile correlation(WQC)method are utilized.Furthermore,NARDL technique estimates reveal that contractionary commercial policy enhances the environmental quality by disrupting the detrimental effects of CCO2e.However,expansionary commercial policy escalates the environmental pollution by boosting the carbon emissions.Also,the exports and the renewable energy improve the ecological quality;however,GDP deteriorates the atmospheric quality by increasing the CCO2e.Besides,WQC method and the trivariate Granger causality test are deployed to confirm the robustness of the results.Based on the findings,some crucial policies are also recommended for sustainable and green development in Pakistan.展开更多
Introduction:The Belt and Road Initiative(BRI)is an important cooperative framework that increasingly affects the global economy,trade,and emission patterns.However,most existing studies pay insufficient attention to ...Introduction:The Belt and Road Initiative(BRI)is an important cooperative framework that increasingly affects the global economy,trade,and emission patterns.However,most existing studies pay insufficient attention to consumption-based emissions,embodied emissions,and non-CO_(2) greenhouse gases(GHGs).This study constructs a GHG emissions database to study the trends and variations in production-based,consumption-based,and embodied emissions associated with BRI countries.Outcome:We find that the per capita GHG emissions of BRI countries are lower than the global average but show significant variation within this group.We also find that trade-embodied emissions between BRI countries and China are growing.As a group,BRI countries are anet exporter of GHGs,with a global share of net export emissions of about 20%.In 2011,nearly 80%of GHG export emissions from BRI countries flowed to non-BRI countries,and nearly 15%flowed to China;about 57%of GHG import emissions were from non-BRI countries,and about 38%were from China.Conclusion:Therefore,this study concludes that the BRI should be used to coordinate climate governance to accelerate and strengthen the dissemination and deployment of low-emissions technologies,strategies,and policies within the BRI so as to avoid a carbon-intensive lock-in effect.展开更多
To evaluate direct greenhouse gas emissions from Membrane Biological Reactor(MBR),measurements of nitrous oxide(N_(2)O)and methane(CH_(4))were made at a pilot-scale MBR treating municipal wastewater Measurements were ...To evaluate direct greenhouse gas emissions from Membrane Biological Reactor(MBR),measurements of nitrous oxide(N_(2)O)and methane(CH_(4))were made at a pilot-scale MBR treating municipal wastewater Measurements were conducted during two campaigns with some changes in processes,i.e.introducing a pre-aeration tank in the second measurement,different distributions of aeration in the treatment line,not the same wastewater inflow rate,two types of ultrafiltration membrane.It was found that about 0.004% and 0.07% of the total ammonium loads were emitted as N_(2)O,CH_(4) emissions were 0.026% and 0.12% of incoming TOC(0.008% and 0.04% of incoming COD)in 2014 and 2018.The obtained N_(2)O emission values were relatively low.The study suggested that a high aeration at the beginning of the treatment line may result in significantly high emissions of both N_(2)O and CH_(4).A significant change in aeration in the membrane ultrafiltration tank did not have the same impact.The MBR process is known for high quality effluent but have been questioned due to its higher carbon footprint due to energy consumption.This study gave a reference case about direct GHG emissions from MBR process and provide information for the further evaluation of MBR processes.展开更多
The argument over fiscal decentralization and carbon dioxide emission(CO_(2))reduction has received much attention.However,evidence to back this claim is limited.Economic theory predicts that fiscal decentralization a...The argument over fiscal decentralization and carbon dioxide emission(CO_(2))reduction has received much attention.However,evidence to back this claim is limited.Economic theory predicts that fiscal decentralization affects environmental quality,but the specifics of this relationship are still up for debate.Some scholars noted that fiscal decentralization might lead to a race to the top,whereas others contended that it would result in a race to the bottom.In light of the current debates in environmental and development economics,this study aims to provide insight into how this relationship may function in South Africa from 1960 to 2020.In contrast to the existing research,the present study uses a novel dynamic autoregressive distributed lag simulation approach to assess the positive and negative changes in fiscal decentralization,scale effect,technique effect,technological innovation,foreign direct investment,energy consumption,industrial growth,and trade openness on CO_(2)emissions.The following are the main findings:(i)Fiscal decentralization had a CO_(2)emission reduction impact in the short and long run,highlighting the presence of the race to the top approach.(ii)Economic growth(as represented by the scale effect)eroded ecological integrity.However,its square(as expressed by technique effect)aided in strengthening ecological protection,validating the environmental Kuznets curve hypothesis.(iii)CO_(2)emissions were driven by energy utilization,trade openness,industrial value-added,and foreign direct investment,whereas technological innovation boosted ecological integrity.Findings suggest that further fiscal decentralization should be undertaken through further devolution of power to local entities,particularly regarding environmental policy issues,to maintain South Africa’s ecological sustainability.South Africa should also establish policies to improve environmental sustainability by strengthening a lower layer of government and clarifying responsibilities at the national and local levels to fulfill the energy-saving functions of fiscal expenditures.展开更多
基金supported by the National Natural Science Foundation of China (4150050140)the Special Fund for Environmental Protection Research in the Public Interest (201509004)
文摘This paper analyzes current urban symbiosis development and application in China, and then conducts a statistical analysis of the emissions reduction of CO2 and CH_4 in relation to recovery of iron and steel scraps, waste paper, and waste plastics from 2011 to 2014 using the greenhouse gas(GHG) emission inventory calculation method provided by the IPCC. Results indicate that the cumulative recovery of renewable resources during China's main urban symbiosis development in 2011e2014 was 803.275 Mt, and the amount of iron and steel scraps, waste paper, and waste plastic recovery was the largest, respectively accounting for 62.2%, 18.0%, and 8.2% of total recovery in 2014. In addition, the cumulative emissions reduction of GHGs in relation to recovery of iron and steel scraps, waste paper, and waste plastics in 2011e2014 was27.962 Mt CO_2-eq, 954.695 Mt CO_2-eq, and 22.502 Mt CO_2-eq, respectively, thereby totaling 1005.159 Mt CO_2-eq. Results show a remarkable GHG emissions reduction during 2011e2014.
基金financially supported by the National Key R&D Program of China(Grant No.2019YFC1908501)the National Natural Science Foundation of China(Grant Nos.72088101,71810107001,and 71690241)+2 种基金the Postdoctoral Science Foundation of China(Grant No.2018M641989)Philosophy and Social Science Foundation of Jiangsu Province(Grant No.2020SJA2358)the China Scholarship Council Program(Grant No.202008320101).
文摘China’s aluminum(Al)production has released a huge amount of greenhouse gas(GHG)emissions.As one of the biggest country of primary Al production,China must mitigate its overall GHG emission from its Al industry so that the national carbon neutrality target can be achieved.Under such a background,the study described in this paper conducts a dynamic material flow analysis to reveal the spatiotemporal evolution features of Al flows in China from 2000 to 2020.Decomposition analysis is also performed to uncover the driving factors of GHG emission generated from the Al industry.The major findings include the fact that China’s primary Al production center has transferred to the western region;the primary Al smelting and carbon anode consumption are the most carbonintensive processes in the Al life cycle;the accumulative GHG emission from electricity accounts for 78.14% of the total GHG emission generated from the Al industry;China’s current Al recycling ratio is low although the corresponding GHG emission can be reduced by 93.73% if all the primary Al can be replaced by secondary Al;and the total GHG emission can be reduced by 88.58% if major primary Al manufacturing firms are transferred from Inner Mongolia to Yunnan.Based upon these findings and considering regional disparity,several policy implications are proposed,including promotion of secondary Al production,support of clean electricity penetration,and relocation of the Al industry.
基金supported by the National Natural Science Foundation of China(NNSFC)grants 42074202,42274196Strategic Priority Research Program of Chinese Academy of Sciences grant XDB41000000ISSI-BJ International Team Interaction between magnetic reconnection and turbulence:From the Sun to the Earth。
文摘Earth’s magnetopause is a thin boundary separating the shocked solar wind plasma from the magnetospheric plasmas,and it is also the boundary of the solar wind energy transport to the magnetosphere.Soft X-ray imaging allows investigation of the large-scale magnetopause by providing a two-dimensional(2-D)global view from a satellite.By performing 3-D global hybrid-particle-in-cell(hybrid-PIC)simulations,we obtain soft X-ray images of Earth’s magnetopause under different solar wind conditions,such as different plasma densities and directions of the southward interplanetary magnetic field.In all cases,magnetic reconnection occurs at low latitude magnetopause.The soft X-ray images observed by a hypothetical satellite are shown,with all of the following identified:the boundary of the magnetopause,the cusps,and the magnetosheath.Local X-ray emissivity in the magnetosheath is characterized by large amplitude fluctuations(up to 160%);however,the maximum line-of-sight-integrated X-ray intensity matches the tangent directions of the magnetopause well,indicating that these fluctuations have limited impact on identifying the magnetopause boundary in the X-ray images.Moreover,the magnetopause boundary can be identified using multiple viewing geometries.We also find that solar wind conditions have little effect on the magnetopause identification.The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will provide X-ray images of the magnetopause for the first time,and our global hybrid-PIC simulation results can help better understand the 2-D X-ray images of the magnetopause from a 3-D perspective,with particle kinetic effects considered.
基金The authors acknowledge the financial support received from the National Natural Science Foundation of China(72061147002).
文摘China removed fertilizer manufacturing subsidies from 2015 to 2018 to bolster market-oriented reforms and foster environmentally sustainable practices.However,the impact of this policy reform on food security and the environment remains inadequately evaluated.Moreover,although green and low-carbon technologies offer environmental advantages,their widespread adoption is hindered by prohibitively high costs.This study analyzes the impact of removing fertilizer manufacturing subsidies and explores the potential feasibility of redirecting fertilizer manufacturing subsidies to invest in the diffusion of these technologies.Utilizing the China Agricultural University Agri-food Systems model,we analyzed the potential for achieving mutually beneficial outcomes regarding food security and environmental sustainability.The findings indicate that removing fertilizer manufacturing subsidies has reduced greenhouse gas(GHG)emissions from agricultural activities by 3.88 million metric tons,with minimal impact on food production.Redirecting fertilizer manufacturing subsidies to invest in green and low-carbon technologies,including slow and controlled-release fertilizer,organic-inorganic compound fertilizers,and machine deep placement of fertilizer,emerges as a strategy to concurrently curtail GHG emissions,ensure food security,and secure robust economic returns.Finally,we propose a comprehensive set of government interventions,including subsidies,field guidance,and improved extension systems,to promote the widespread adoption of these technologies.
基金the European Research Council for starting grant 200141-QuESpace,with which the Vlasiator model was developedconsolidator grant 682068-PRESTISSIMO awarded for further development of Vlasiator and its use in scientific investigations+4 种基金Academy of Finland grant numbers 338629-AERGELC’H,339756-KIMCHI,336805-FORESAIL,and 335554-ICT-SUNVACThe Academy of Finland also supported this work through the PROFI4 grant(grant number 3189131)support from the NASA grants,80NSSC20K1670 and 80MSFC20C0019the NASA GSFC FY23 IRADHIF funds。
文摘Solar wind charge exchange produces emissions in the soft X-ray energy range which can enable the study of near-Earth space regions such as the magnetopause,the magnetosheath and the polar cusps by remote sensing techniques.The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)and Lunar Environment heliospheric X-ray Imager(LEXI)missions aim to obtain soft Xray images of near-Earth space thanks to their Soft X-ray Imager(SXI)instruments.While earlier modeling works have already simulated soft X-ray images as might be obtained by SMILE SXI during its mission,the numerical models used so far are all based on the magnetohydrodynamics description of the space plasma.To investigate the possible signatures of ion-kinetic-scale processes in soft Xray images,we use for the first time a global hybrid-Vlasov simulation of the geospace from the Vlasiator model.The simulation is driven by fast and tenuous solar wind conditions and purely southward interplanetary magnetic field.We first produce global X-ray images of the dayside near-Earth space by placing a virtual imaging satellite at two different locations,providing meridional and equatorial views.We then analyze regional features present in the images and show that they correspond to signatures in soft X-ray emissions of mirrormode wave structures in the magnetosheath and flux transfer events(FTEs)at the magnetopause.Our results suggest that,although the time scales associated with the motion of those transient phenomena will likely be significantly smaller than the integration time of the SMILE and LEXI imagers,mirror-mode structures and FTEs can cumulatively produce detectable signatures in the soft X-ray images.For instance,a local increase by 30%in the proton density at the dayside magnetopause resulting from the transit of multiple FTEs leads to a 12%enhancement in the line-of-sight-and time-integrated soft X-ray emissivity originating from this region.Likewise,a proton density increase by 14%in the magnetosheath associated with mirror-mode structures can result in an enhancement in the soft X-ray signal by 4%.These are likely conservative estimates,given that the solar wind conditions used in the Vlasiator run can be expected to generate weaker soft X-ray emissions than the more common denser solar wind.These results will contribute to the preparatory work for the SMILE and LEXI missions by providing the community with quantitative estimates of the effects of small-scale,transient phenomena occurring on the dayside.
文摘In recent years,the United Arab Emirates(UAE)has developed strategies to increase renewable power generation and reduce emis-sions to net zero by 2050.Electricity generation and energy-intensive industries(EII)have the largest potentials for emission reduc-tion.Therefore,an up-to-date inventory of greenhouse gas emissions and a study of the pathways to achieving the 2050 targets are essential.This study focuses on power production and EII(aluminium,steel and cement).The structure of these sectors is modelled and simulated up to 2050 using a system dynamics(SD)methodology.The SD model is validated to reflect the real-world state of the system using the emissions inventory projections as reference modes.Nineteen mitigation policies are considered in the selected sectors and four policy scenarios were simulated.The results show that implementing the Energy Strategy 2050 in the power sector can result in a reduction of 63.5%in emissions in that sector,which translates into a reduction of 33.5%overall by 2050.Additionally,implementing all identified mitigation strategies to full utilization in EII yields a 94%reduction in that sector,which translates into a 78%reduction overall.Decarbonizing the aluminium industry yields the highest emissions reductions,followed by power produc-tion,then cement and finally steel.In the best-case scenario,22.1%of the business-as-usual emissions are still released and further decarbonization—mainly in the power sector—will be required.This is achievable given the trajectory of the UAE’s successful nuclear energy programme and the prospect of utilizing carbon capture,utilization and storage even further.
文摘The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this sector.In this paper,international environmental governance in the steel industry is reviewed,and the current state of development of low-carbon technologies is discussed.Additionally,low-carbon pathways for the steel industry at the current time are proposed,emphasizing prevention and treatment strategies.Furthermore,the prospects of low-carbon technologies are explored from the perspective of transitioning the energy structure to a“carbon-electricity-hydrogen”relationship.Overall,steel enterprises should adopt hydrogen-rich metallurgical technologies that are compatible with current needs and process flows in the short term,based on the carbon substitution with hydrogen(prevention)and the CCU(CO_(2) capture and utilization)concepts(treatment).Additionally,the capture and utilization of CO_(2) for steelmaking,which can assist in achieving short-term emission reduction targets but is not a long-term solution,is discussed.In conclusion,in the long term,the carbon metallurgical process should be gradually supplanted by a hydrogen-electric synergistic approach,thus transforming the energy structure of existing steelmaking processes and attaining near-zero carbon emission steelmaking technology.
文摘This paper analyzes the key indicators of the impact assessment the teleworking as practice of performing regular work from home or from a location close to home,on reducing the number of travel and reduced carbon emissions transportation activities.Models and methodologies described in the literature are a good basis for a better and more comprehensive and understanding of the positives and negative effects teleworking and real opportunities of its wider application,however there is a lack of systemic analysis.Development of a set of indicators for assessing emission reduction induced by the measures to promote sustainable transport.Due to the complexity of the transport sector,a change in any indicator models have side effects on other indicators(unwanted and multiplier effects)and what is the theme of our research work.
基金the National Key Basic Research and Development Program of China (973 plan: 2003CB415201)
文摘The process-oriented model Forest-DNDC describing biogeochemical cycling of C and N and GHGs (greenhouse gases) fluxes (CO2, NO and N2O) in forest ecosystems was applied to simulate carbon sequestration and GHGs emissions in Abies fabric forest of the Gongga Mountains at southeastern edge of the Tibetan Plateau. The results indicated that the simulated gross primary production (GPP) of Abies fabric forest was strongly affected by temperature. The annual total GPP was 24,245.3 kg C ha-1 yr-1 for 2005 and 26,318.8 kg C ha-1 yr-1 for 2006, respectively. The annual total net primary production (NPP) was 5,935.5 and 4,882.2 kg C ha-1 yr-1 for 2005 and 2006, and the annual total net ecosystem production (NEP) was 4,815.4 and 3,512.8 kg C ha-1 yr-1 for 2005 and 2006, respectively. The simulated seasonal variation in CO2 emissions generally followed the seasonal variations in temperature and precipitation. The annual total CO2 emissions were 3,109.0 and 4,821.0 kg C ha-1 yr-1 for 2005 and 2006, the simulated annual total N2O emissions from forest soil were 1.47 and 1.36 kg N ha-1 yr-1 for 2005 and 2006, and the annual total NO emissions were 0.09 and 0.12 kg N ha-1 yr-1 for 2005 and 2006, respectively.
文摘Abies fabric forest in the eastern slope of Gongga mountain is one type of subalpine dark coniferous forests of southwestern China. It is located on the southeastern edge of the Qinghai-Tibet plateau and is sensitive to climatic changes. A process-oriented biogeochemical model, Forest-DNDC, was applied to simulate the effects of climatic factors, temperature and precipitation changes on carbon characteristics, and greenhouse gases (GHGs) emissions in A. fabric forest. Validation indicated that the Forest-DNDC could be used to predict carbon characteristics and GHGs emissions with reasonable accuracy. The model simulated carbon fluxes, soil carbon dynamics, soil CO2, N2O, and NO emissions with the changes of temperature and precipitation conditions. The results showed that with variation in the baseline temperature from -2℃to +2℃, the gross primary production (GPP) and soil organic carbon (SOC) increased, and the net primary production (NPP) and net ecosystem production (NEP) decreased because of higher respiration rate. With increasing baseline precipitation the GPP and NPP increased slightly, and the NEP and SOC showed decreasing trend. Soil CO2 emissions increased with the increase of temperature, and CO2 emissions changed little with increased baseline precipitation. With increased temperature and decreased baseline temperature, the total annual soil N2O emissions increased. With the variation of baseline temperature from -2℃to +2℃, the total annual soil NO emissions increased. The total annual N2O and NO emissions showed increasing trends with the increase of precipitation. The biogeochemical simulation of the typical forest indicated that temperature changes strongly affected carbon fluxes, soil carbon dynamics, and soil GHGs emissions. The precipitation was not a principal factor affecting carbon fluxes, soil carbon dynamics, and soil CO2 emissions, but changes in precipitation could exert strong effect on soil N2O and NO emissions.
文摘This study was performed to estimate the emission of non-CO 2 greenhouse gases(GHGs) from biomass burning at a large fire area.The extended methodology adopted the IPCC Guidelines(2003) equation for use on data from the Samcheok forest fire gathered using 30 m resolution Landsat TM satellite imagery,digital forest type maps,and growing stock information per hectare by forest type in 1999.Normalized burn ratio(NBR) technique was employed to analyze the area and severity of the Samcheok forest fire that occurred in 2000.The differences between NBR from pre-and post-fire datasets are examined to determine the extent and degree of change detected from burning.The results of burn severity analysis by dNBR of the Samcheok forest fire area revealed that a total of 16,200 ha of forest were burned.The proportion of the area characterized by a 'Low' burn severity(dNBR below 152) was 35%,with 'Moderate'(dNBR 153-190) and 'High'(dNBR 191-255) areas were at 33% and 32%,respectively.The combustion efficiency for burn severity was calculated as 0.43 for crown fire where burn severity was 'High',as 0.40 for 'Moderate' severity,and 0.15 for 'Low' severity surface fire.The emission factors for estimating non-CO 2 GHGs were separately applied to CO 130,CH 4 9,NO x 0.7 and N 2 O 0.11.Non-CO 2 GHGs emissions from biomass burning in the Samcheok forest fire area were estimated to be CO 44.100,CH 4 3.053,NO x 0.238 and N 2 O 0.038 Gg.
基金supported by National Natural Science Foundation(Grant Nos.41875164 and 92044303)。
文摘In recent years,China has implemented several measures to improve air quality.The Beijing-Tianjin-Hebei(BTH)region is one area that has suffered from the most serious air pollution in China and has undergone huge changes in air quality in the past few years.How to scientifically assess these change processes remain the key issue in further improving the air quality over this region in the future.To evaluate the changes in major air pollutant emissions over this region,this paper employs ensemble Kalman filtering(EnKF)for integrating the national ground monitoring pollutant observation data and the Nested Air Quality Prediction Modeling System(NAQPMS)simulation data to inversely estimate the emission rates of SO_(2),NOX,CO,and primary PM_(2.5)over BTH region in February from 2014 to 2019.The results show that SO_(2),NOX,CO,and primary PM_(2.5)emissions in the BTH region decreased in February from 2014 to 2019 by 83%,37%,41%,and 42%,while decreases in Beijing during this period were 86%,67%,59%,and 65%,respectively.Compared with the prior emission inventory,the inversion emission inventory reduces the uncertainty of multi-pollutant simulation in the BTH region,with simulated root mean square errors of the monthly average concentrations of SO_(2),NOX,PM_(2.5),and CO reduced by 41%,30%,31%,and 22%,respectively.The average uncertainties of SO_(2),NOX,PM_(2.5),and CO inversion emissions in2014-19 are±14.03%yr^(-1),±28.91%yr^(-1),±126.15%yr^(-1),and±43.58%yr^(-1).Compared with the uncertainty of MEIC emission,the uncertainties of all species changed by+2%yr^(-1),-2%yr^(-1),-26%yr^(-1),and-4%yr^(-1),respectively.The spatial distribution results illustrate that air pollutant emissions are mainly distributed over the eastern and southern BTH regions.The spatial gap between the inversion emissions and MEIC emissions was further closed in 2019 compared to 2014.The results of this paper can provide a new reference for assessing changes in air pollution emissions over the BTH region in recent years and validating a bottom-up emission inventory.
基金supported by the National Natural Science Foundation of China(Grants No.42271178 and 41801104).
文摘The Asia-Pacific Economic Cooperation(APEC)is contemplating expanding its list of environmental goods(EG)for trade liberalization to fight climate change.In support of doing so,this study proposes that a long list that retains controversies is better for carbon emission reduction than a short common list.This study examines four mechanisms of longer lists:enlarging market scales,enriching product mixes,enhancing product sophistication,and enriching trade patterns.Using China’s emerging EG trade during the 2001-2015 period as a case study,this study compares four EG lists with different EG.The results show that:(1)a longer list reduces carbon emissions from both imports and exports,making domestic regions with different advantages have better chances of improving carbon efficiencies.(2)Product sophistication reduces the emission gap between trading partners,regardless of the length of EG lists.(3)China’s EG exports contribute to carbon reduction in leading regions,while EG imports provide laggard regions with better chances of reducing carbon emissions.These findings provide three implications for future list-making:it is important to(1)seek a long and inclusive list rather than a short common list,(2)shift the focus from environmental end-use to the technological contents of products,and(3)balance the demand of laggard regions to import and the capacity of leading regions to export.
文摘The current study extends the previous literature by exploring the effects of a newly discovered driver,i.e.,import taxes(as a proxy for commercial policies),on the consumption-based carbon emissions(CCO2e)for 1990Q1-2017Q4.For empirical analysis,several tests and methods,including Augmented Dickey–Fuller unit root test,Zivot–Andrews unit root test,asymmetric cointegration bound testing approach,non-linear ARDL,Wald-test,Granger causality test and wavelet quantile correlation(WQC)method are utilized.Furthermore,NARDL technique estimates reveal that contractionary commercial policy enhances the environmental quality by disrupting the detrimental effects of CCO2e.However,expansionary commercial policy escalates the environmental pollution by boosting the carbon emissions.Also,the exports and the renewable energy improve the ecological quality;however,GDP deteriorates the atmospheric quality by increasing the CCO2e.Besides,WQC method and the trivariate Granger causality test are deployed to confirm the robustness of the results.Based on the findings,some crucial policies are also recommended for sustainable and green development in Pakistan.
基金This work was supported by the National Key Research and Development Program of China[2018YFA0606503]the National Natural Science Foundation of China[71590243,71673162].
文摘Introduction:The Belt and Road Initiative(BRI)is an important cooperative framework that increasingly affects the global economy,trade,and emission patterns.However,most existing studies pay insufficient attention to consumption-based emissions,embodied emissions,and non-CO_(2) greenhouse gases(GHGs).This study constructs a GHG emissions database to study the trends and variations in production-based,consumption-based,and embodied emissions associated with BRI countries.Outcome:We find that the per capita GHG emissions of BRI countries are lower than the global average but show significant variation within this group.We also find that trade-embodied emissions between BRI countries and China are growing.As a group,BRI countries are anet exporter of GHGs,with a global share of net export emissions of about 20%.In 2011,nearly 80%of GHG export emissions from BRI countries flowed to non-BRI countries,and nearly 15%flowed to China;about 57%of GHG import emissions were from non-BRI countries,and about 38%were from China.Conclusion:Therefore,this study concludes that the BRI should be used to coordinate climate governance to accelerate and strengthen the dissemination and deployment of low-emissions technologies,strategies,and policies within the BRI so as to avoid a carbon-intensive lock-in effect.
文摘To evaluate direct greenhouse gas emissions from Membrane Biological Reactor(MBR),measurements of nitrous oxide(N_(2)O)and methane(CH_(4))were made at a pilot-scale MBR treating municipal wastewater Measurements were conducted during two campaigns with some changes in processes,i.e.introducing a pre-aeration tank in the second measurement,different distributions of aeration in the treatment line,not the same wastewater inflow rate,two types of ultrafiltration membrane.It was found that about 0.004% and 0.07% of the total ammonium loads were emitted as N_(2)O,CH_(4) emissions were 0.026% and 0.12% of incoming TOC(0.008% and 0.04% of incoming COD)in 2014 and 2018.The obtained N_(2)O emission values were relatively low.The study suggested that a high aeration at the beginning of the treatment line may result in significantly high emissions of both N_(2)O and CH_(4).A significant change in aeration in the membrane ultrafiltration tank did not have the same impact.The MBR process is known for high quality effluent but have been questioned due to its higher carbon footprint due to energy consumption.This study gave a reference case about direct GHG emissions from MBR process and provide information for the further evaluation of MBR processes.
文摘The argument over fiscal decentralization and carbon dioxide emission(CO_(2))reduction has received much attention.However,evidence to back this claim is limited.Economic theory predicts that fiscal decentralization affects environmental quality,but the specifics of this relationship are still up for debate.Some scholars noted that fiscal decentralization might lead to a race to the top,whereas others contended that it would result in a race to the bottom.In light of the current debates in environmental and development economics,this study aims to provide insight into how this relationship may function in South Africa from 1960 to 2020.In contrast to the existing research,the present study uses a novel dynamic autoregressive distributed lag simulation approach to assess the positive and negative changes in fiscal decentralization,scale effect,technique effect,technological innovation,foreign direct investment,energy consumption,industrial growth,and trade openness on CO_(2)emissions.The following are the main findings:(i)Fiscal decentralization had a CO_(2)emission reduction impact in the short and long run,highlighting the presence of the race to the top approach.(ii)Economic growth(as represented by the scale effect)eroded ecological integrity.However,its square(as expressed by technique effect)aided in strengthening ecological protection,validating the environmental Kuznets curve hypothesis.(iii)CO_(2)emissions were driven by energy utilization,trade openness,industrial value-added,and foreign direct investment,whereas technological innovation boosted ecological integrity.Findings suggest that further fiscal decentralization should be undertaken through further devolution of power to local entities,particularly regarding environmental policy issues,to maintain South Africa’s ecological sustainability.South Africa should also establish policies to improve environmental sustainability by strengthening a lower layer of government and clarifying responsibilities at the national and local levels to fulfill the energy-saving functions of fiscal expenditures.
