Knowledge of decoupling indicators and its determinants is useful for formulating targeted policy recommendations. To this end, the Log-Mean Divisia Index and Tapio models were applied in this paper to study the decou...Knowledge of decoupling indicators and its determinants is useful for formulating targeted policy recommendations. To this end, the Log-Mean Divisia Index and Tapio models were applied in this paper to study the decoupling relationship among economic growth and GHG emissions in Cameroon over the period 1971-2014. The analyzes were conducted according to the three major periods that marked Cameroon after independence and the decoupling indicators were broken down into seven factors while considering the three main GHGs emitted in this country (i.e. CO2, CH4, and N2O). The results showed that weak decoupling, strong decoupling, and strong negative decoupling occurred in Cameroon during the periods 1971-1984 and 1994-2014 which represent the periods before and after the economic crisis, respectively. In addition to these three decoupling statuses, recessive decoupling only appeared during the economic crisis period (1984-1994). From 1971 to 1984 and between 1994 and 2014, carbon intensity, economic activity, population, and emission factor not only contributed to the increase of Cameroon’s GHG (particularly CO2) emissions but also prevented decoupling. Unlike the period 1984-1994, energy intensity contributed to reducing environmental pollution while promoting decoupling during the periods 1971-1984 and 1994-2014. Although all played an important role in decoupling, we found that after the introduction of natural gas into the country’s energy mix from 2007, the effect of renewable energies on the mitigation of Cameroon’s CO2 emissions remained higher than the substitution of fossil fuels. However, to develop a cleaner economy, Cameroon should maintain modest economic growth and continuously transform economic development pathways, while encouraging the use of renewable energy to further reduce energy intensity per unit of GDP per capita.展开更多
This experiment was conducted in Xinxiang, Henan from June 2013 to June 2014. Total four treatments were designed including farmers ’ common practice （F, 250 kg/hm^2）, 80% F （LF, 200 kg/hm^2）, 80% F＋biochar （LF...This experiment was conducted in Xinxiang, Henan from June 2013 to June 2014. Total four treatments were designed including farmers ’ common practice （F, 250 kg/hm^2）, 80% F （LF, 200 kg/hm^2）, 80% F＋biochar （LFC） and no fertilizer （CK） to measure the dynamic emissions of CO2 and N2O from a summer maize-winter wheat field by static chamber-gas chromatography method. The results showed that the soil CO2 emission was 21.8-1 022.7 mg/（m^2·h）, and was mainly influenced by soil temperature and moisture content. During the growth of summer maize, the soil CO2 emission was more significantly affected by soil moisture con-tent; and in winter wheat growing season, it was more significantly affected by soil temperature in the top 5 cm. The LF and LFC treatments significantly reduced the soil cumulative CO2 emission, especial y during the growth of winter wheat. Fertiliza-tion and irrigation were the main factors influencing the soil N2O emission. The soil N2O emission during the fertilization period accounted for 73.9%-74.5% and 40.5%-43.6% of the soil cumulative N2O emission during the summer maize-and winter wheat-growing season, respectively. The peak of emission fluxes was determined by fertilization amount, while the occurrence time of emission peak and emission re-duction effect were influenced by irrigation. The LF treatment reduced the soil cu-mulative N2O emission by 15.7%-16.8% and 18.1%-18.5% during the growth period of summer maize and winter wheat, respectively. Reduced nitrogen fertilization is an effective way for reducing N2O emission in intensive high-yielding farmland. Under a suitable nitrogen level （200 kg/hm^2）, the application of biochar showed no significant effect on the soil N2O emission in a short term. The N2O emission factors of the L and LF treatments were 0.60% and 0.56%, respectively. ln the intensive high-yield-ing farmland of North China, reducing the nitrogen application amount is an appro-priate measure to mitigate greenhouse gas emissions without crop yield loss.展开更多
This study discusses a method of quantifying emissions from surface coal mining that has been trialled in Australia. The method is based on direct measurement of surface emissions from uncovered coal seams in mine pit...This study discusses a method of quantifying emissions from surface coal mining that has been trialled in Australia. The method is based on direct measurement of surface emissions from uncovered coal seams in mine pits, concurrent measurement of residual gas content of blasted coal in mine pits, and measurement of pre-mining gas content of the same seam from cores retrieved from exploration boreholes drilled away from active mining. The results from one of the mines studied are presented in this paper. In this mine,the pre-mining gas content of the target seam was measured using cores from an exploration borehole away from active mining. Gas content varied from 0.7 to 0.8 m3/t and gas composition varied from16% to 21% CH4(84–79% CO2). In-pit measurements included seam surface emissions and residual gas content of blasted and ripped coal. Residual gas content varied from 0.09 to 0.15 m3/t, less than twofold across the mine pit. Composition of the residual gas was in general 90% CO2and 10% CH4, with slight variation between samples. Coal seam surface emissions varied from 1.03 to 7.50 mL of CO2-e per minute and per square meter of the coal seam surface, a sevenfold variation across the mine pit.展开更多
Adipic acid is an important petrochemical product,and its production process emits a high concentration of greenhouse gas N_2 O.This paper aims to provide quantitative references for relevant authorities to formulate ...Adipic acid is an important petrochemical product,and its production process emits a high concentration of greenhouse gas N_2 O.This paper aims to provide quantitative references for relevant authorities to formulate greenhouse gas control roadmaps.The forecasting method of this paper is consistent with the published national inventory in terms of caliber.Based on the N_2 O abatement technical parameters of adipic acid and the production trend,this paper combines the scenario analysis and provides a measurement of comprehensive N_2 O abatement effect of the entire industry in China.Four future scenarios are assumed.The baseline scenario(BAUS) is a frozen scenario.Three emission abatement scenarios(ANAS,SNAS,and ENAS) are assumed under different strength of abatement driving parameters.The results show that China's adipic acid production process can achieve increasingly significant N_2 O emission abatement effects.Compared to the baseline scenario,by 2030,the N_2 O emission abatements of the three emission abatement scenarios can reach 207-399 kt and the emission abatement ratios can reach 32.5%-62.6%.By 2050,the N_2 O emission abatements for the three emission abatement scenarios can reach 387-540 kt and the emission abatement ratios can reach 71.4%-99.6%.展开更多
In this study, comparison of model results and satellite observations reveals that the Whole-Atmosphere Community Climate Model （WACCM-3） reasonably well reproduced the distributions and seasonal vari- ations of C10...In this study, comparison of model results and satellite observations reveals that the Whole-Atmosphere Community Climate Model （WACCM-3） reasonably well reproduced the distributions and seasonal vari- ations of C10 and HC1 concentrations. In three greenhouse gas emission scenarios （A1B, A2, and B1）, the C10, C1, C1ONO2, and HC1 concentrations would gradually decrease with time as emissions of ozone depleting substances （ODS） steadily decrease. The rates of the changes in the C10, C1, C1ONO2, and HC1 concentrations are different in the same emission scenario and the rates of change in the same composition concentration are different for different emission scenarios. The C10, C1, and C1ONO2 concentrations de- crease fastest in scenario A2, next fastest in scenario A1B, and slowest in scenario B1. In contrast, the HC1 concentration decreases fastest in scenario B1. The ozone concentration recovers quickly, and is highest in scenario A2. The results show that a rapid decrease in the C10 concentration is an important reason for the accelerated recovery of the ozone layer in scenario A2.展开更多
In coal mines in such countries as China and Russia,most of the coal mine methane(CMM) generated during mining is emitted to the atmosphere without any effective usage,because the methane concentration of CMM is relat...In coal mines in such countries as China and Russia,most of the coal mine methane(CMM) generated during mining is emitted to the atmosphere without any effective usage,because the methane concentration of CMM is relatively low and not allowed to be used as fuel for safety reasons.Methane is one of the greenhouse gases.Therefore,if it becomes possible to concentrate CMM to an acceptable level for use as fuel,this will greatly contribute to reduction of greenhouse gas emissions.With the aim of gaining approval as a greenhouse gas emission reduction of the clean development mechanism(CDM) or joint implementation(JI) project,we developed a CMM concentration system to apply the vacuum pressure swing adsorption(VPSA) technology using a high methane-selective adsorbent by Osaka Gas Co.,Ltd.The pilot-scale plant of a CMM concentration system was installed in a coal mine in Fuxin City in the northeastern China and a demonstration test was commenced in December 2008.As the result,the pilot-scale plant successfully concentrated the raw material gas with a methane concentration of 21% and a flow rate of 1000 Nm3/h to 48%,which exceeded the target of the methane concentration performance(a 25% increase).The methane recovery rate reached 93%.展开更多
The global steel production has been growing for the last 50 years, from 200 Mt in 1950s to 1 240 Mt in 2006. Iron and steel making industry is one of the most energy-intensive industries, with an annual energy consum...The global steel production has been growing for the last 50 years, from 200 Mt in 1950s to 1 240 Mt in 2006. Iron and steel making industry is one of the most energy-intensive industries, with an annual energy consumption of about 24 EJ, 5% of the world＇s total energy consumption. The steel industry accounts for 3%-4% of totat world greenhouse gas emissions. Enhancing energy efficiency and employing energy saving/recovering technologies such as coke dry quechning （CDQ） and top pressure recovery turbine （TRT） can be short-term approaches to the steel industry to reduce greenhouse gas emission. The long-term approaches to achieving a significant reduction in CO2 emissions from the steel industry would be through developing and applying CO2 breakthrough technologies for iron and steel making, and：through increasing use of renewable energy for iron and steel making. Thus, an overview of new CO2 breakthrough technologies for iron and steel making was made.展开更多
Petrochemical enterprises have become a major source of global greenhouse gas(GHG)emissions.Yet,due to the unavailability of basic data,there is still a lack of case studies to quantify GHG emissions and provide petro...Petrochemical enterprises have become a major source of global greenhouse gas(GHG)emissions.Yet,due to the unavailability of basic data,there is still a lack of case studies to quantify GHG emissions and provide petrochemical enterprises with guidelines for implementing energy conservation and emission reduction strategies.Therefore,this study conducted a life cycle assessment(LCA)analysis to estimate the GHG emissions of four typical petrochemical enterprises in China,using first-hand data,to determine possible emission reduction measures.The analytical data revealed that Dushanzi Petrochemical(DSP)has the highest GHG emission intensity(1.17 tons CO_(2)e/ton),followed by Urumqi Petrochemical(UP)(1.08 tons CO_(2)e/ton),Dalian Petrochemical(DLP)(average 0.58 tons CO_(2)e/ton)and Karamay Petrochemical(KP)(average 0.50 tons CO_(2)e/ton)over the whole life cycle.At the same time,GHG emissions during fossil fuel combustion were the largest contributor to the whole life cycle,accounting for about 77.31%–94.27% of the total emissions.In the fossil-fuel combustion phase,DSP had the highest unit GHG emissions(1.20 tons CO_(2)e),followed by UP(0.89 tons CO_(2)e).In the industrial production phase,DLP had the highest unit GHG emissions(average 0.13 tons CO_(2)e/ton),followed by UP(0.10 tons CO_(2)e/ton).During the torch burning phase,torch burning under accident conditions was the main source of GHG emissions.It is worth noting that the CO_(2) recovery stage has"negative value,"indicating that it will bring some environmental benefits.Further scenario analysis shows that effective policies and advanced technologies can further reduce GHG emissions.展开更多
The work is a case study of a cruise ship supplied by liquefied natural gas(LNG)and equipped with a solid oxide fuel cell(SOFC).It is supposed that a 20 MW SOFC plant is installed on-board to supply hotel loads and as...The work is a case study of a cruise ship supplied by liquefied natural gas(LNG)and equipped with a solid oxide fuel cell(SOFC).It is supposed that a 20 MW SOFC plant is installed on-board to supply hotel loads and assisting three dual-fuel(DF)diesel/LNG generator sets.LNG consumption and emissions are estimated both for the SOFC plant and DF generator sets.It results that the use of LNG-SOFC plant in comparison to DF generator sets allows to limit significantly the SO_(x),CO,NO_(x),PM emissions and to reduce the emission of CO_(2)by about 11%.A prediction of the weight and volume of the SOFC plant is conducted and a preliminary modification of the general arrangement of the cruise ship is suggested,according to the latest international rules.It results that the SOFC plant is heavier and occupies more volume on board than a DF gen-set;nevertheless,these features do not affect the floating and the stability of the cruise ship.展开更多
Agricultural soils are deficient of phosphorus （P） worldwide. Phosphatic fertilizers are therefore applied to agricultural soils to improve the fertility and to increase the crop yield. However, the effect of phosph...Agricultural soils are deficient of phosphorus （P） worldwide. Phosphatic fertilizers are therefore applied to agricultural soils to improve the fertility and to increase the crop yield. However, the effect of phosphorus application on soil N2O emissions has rarety been studied. Therefore, we conducted a laboratory study to investigate the effects P addition on soil N2O emissions from P deficient alluvial soil under two levels of nitrogen （N） fertilizer and soil moisture. Treatments were arranged as follows： P （0 and 20 mg P kg-1） was applied to soil under two moisture levels of 60 and 90% water filled pore space （WFPS）. Each P and moisture treatment was further treated with two levels of N fertilizer （0 and 200 mg N kg-1 as urea）. Soil variables including mineral nitrogen （NH4＋-N and NO3--N）, available P, dissolved organic carbon （DOC）, and soil N2O emissions were measured throughout the study period of 50 days. Results showed that addition of P increased N2O emis- sions either under 60% WFPS or 90% WFPS conditions. Higher N2O emissions were observed under 90% WFPS when compared to 60% WFPS. Application of N fertilizer also enhanced N2O emissions and the highest emissions were 141 μg N2O kg-1 h-1 in P＋N treatment under 90% WFPS. The results of the present study suggest that P application markedly increases soil N2O emissions under both low and high soil moisture levels, and either with or without N fertilizer application.展开更多
Market-based emission trading schemes(ETSs) are widely used in the developed world to reduce greenhouse gas(GHG) emissions which are perceived as the source of global climate change. China, as the largest GHG emitter ...Market-based emission trading schemes(ETSs) are widely used in the developed world to reduce greenhouse gas(GHG) emissions which are perceived as the source of global climate change. China, as the largest GHG emitter in the world, is committed to introducing an ETS to reduce emissions. Here we reviewed existing ETSs and sustainable energy policies worldwide as well as China's pilot programs. These studies were conducted in order to propose recommendations for national initiatives and strategies to be implemented in China in relation to climate change adaptation and mitigation. It has been shown that setting emission caps in the context of a national emission intensity target is difficult. However, implementing reliable systems for measurement, reporting, and verification of emissions are essential. A two-level management system(by central and provincial governments) for carbon trading is beneficial to ensure uniform standards and compliance while maintaining flexibility. Persistent political support from, and effective coordination of, policies by the government are crucial. In addition, strengthening of institutional innovation, and the establishment of a national GHG emissions information system, are of equal importance. This vital information could provide a great opportunity for China to re-define its economic growth and take global leadership in combatting climate change.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
Elevated CO_(2)(eCO_(2))and rice cultivars can strongly alter CH_(4)and N_(2)O emissions from paddy fields.However,detailed information on how their interaction affects greenhouse gas fluxes in the field is still lack...Elevated CO_(2)(eCO_(2))and rice cultivars can strongly alter CH_(4)and N_(2)O emissions from paddy fields.However,detailed information on how their interaction affects greenhouse gas fluxes in the field is still lacking.In this study,we investigated CH_(4)and N_(2)O emissions and rice growth under two contrasting rice cultivars(the strongly and weakly responsive cultivars)in response to eCO_(2),200μmol mol^(-1)higher than the ambient CO_(2)(aCO_(2)),in Chinese subtropical rice systems relying on a multi-year in-situ free-air CO_(2)enrichment platform from 2016 to 2018.The results showed that compared to aCO_(2),eCO_(2)increased rice yield by 7%-31%,while it decreased seasonal cumulative CH_(4)and N_(2)O emissions by 10%-59%and 33%-70%,respectively,regardless of rice cultivar.The decrease in CH_(4) emissions under eCO_(2)was possibly ascribed to the lower CH_(4)production potential(MPP)and the higher CH_(4)oxidation potential(MOP)correlated with the higher soil redox potential(Eh)and O_(2)concentration([O_(2)])in the surface soil.The mitigating effect of eCO_(2)on N_(2)O emissions was likely associated with the reduction of soil soluble N content.The strongly responsive cultivars had lower CH_(4)and N_(2)O emissions than the weakly re sponsive cultivars,and the main reason might be that the former induced higher soil Eh and[O_(2)]in the surface soil and had larger plant biomass and greater N uptake.The findings indicated that breeding strongly responsive cultivars with the potential for greater rice production and lower greenhouse gas emissions is an effective agricultural practice to ensure food security and environmental sustainability under future climate change scenarios.展开更多
Nitrification inhibitors are widely used in agriculture to mitigate nitrous oxide(N_(2)O)emission and increase crop yield.However,no concrete information on their mitigation of N_(2)O emission is available under soil ...Nitrification inhibitors are widely used in agriculture to mitigate nitrous oxide(N_(2)O)emission and increase crop yield.However,no concrete information on their mitigation of N_(2)O emission is available under soil and environmental conditions as in Pakistan.A field experiment was established using a silt clay loam soil from Peshawar,Pakistan,to study the effect of urea applied in combination with a nitrification inhibitor,nitrapyrin(2-chloro-6-tri-chloromethyl pyridine),and/or a plant growth regulator,gibberellic acid(GA_3),on N_(2)O emission and the nitrogen(N)uptake efficiency of maize.The experimental design was a randomized complete block with five treatments in four replicates:control with no N(CK),urea(200 kg N ha^(-1))alone,urea in combination with nitrapyrin(700 g ha^(-1)),urea in combination with GA_3(60 g ha^(-1)),and urea in combination with nitrapyrin and GA_3.The N_(2)O emission,yield,N response efficiency,and total N uptake were measured during the experimental period.The treatment with urea and nitrapyrin reduced total N_(2)O emission by 39%–43%and decreased yield-scaled N_(2)O emission by 47%–52%,relative to the treatment with urea alone.The maize plant biomass,grain yield,and total N uptake increased significantly by 23%,17%,and 15%,respectively,in the treatment with urea and nitrapyrin,relative to the treatment with urea alone,which was possibly due to N saving,lower N loss,and increased N uptake in the form of ammonium;they were further enhanced in the treatment with urea,nitrapyrin,and GA_3 by 27%,36%,and 25%,respectively,probably because of the stimulating effect of GA_3 on plant growth and development and the reduction in biotic and abiotic stresses.These results suggest that applying urea in combination with nitrapyrin and GA_3 has the potential to mitigate N_(2)O emission,improve N response efficiency,and increase maize yield.展开更多
Seasonally flooded várzea forests of Western Amazonia are one of the most productive and biodiverse wetland forests in the world.However,data on their soil CO_(2)emissions,soil organic matter decomposition rates,...Seasonally flooded várzea forests of Western Amazonia are one of the most productive and biodiverse wetland forests in the world.However,data on their soil CO_(2)emissions,soil organic matter decomposition rates,and soil C stocks are scarce.This is a concern because hydrological changes are predicted to lead to increases in the height,extent,and duration of seasonal floods,which are likely to have a significant effect on soil C stocks and fluxes.However,with no empirical data,the impact of altered flood regimes on várzea soil C cycles remains uncertain.This study quantified the effects of maximum annual flood height and soil moisture on soil CO_(2)efflux rate(R_(s))and soil organic matter decomposition rate(k)in the várzea forests of Pacaya Samiria National Reserve,Peru.The study was conducted between May and August 2017.The results showed that R_(s)(10.6–182.7 mg C m^(-2)h^(-1))and k(0.016–0.078)varied between and within sites,and were considerably lower than the values reported for other tropical forests.In addition,R_(s)was negatively affected by flood height(P<0.01)and soil moisture(P<0.001),and it decreased with decreasing river levels post flooding(P<0.001).In contrast,k was not affected by any of the above-mentioned factors.Soil moisture was the dominant factor influencing R_(s),and it was significantly affected by maximum flood height,even after the floods had subsided(P<0.001).Consequently,we concluded that larger floods will likely lead to reduced R_(s),whilst k could remain unchanged but with decomposition processes becoming more anaerobic.展开更多
The anthropogenic CO_(2) emission is contributed to the rapid increase in CO_(2) concentration.In the current study the anthropogenic CO_(2) emission in the Middle East(ME)is investigated using 6 years columnaveraged ...The anthropogenic CO_(2) emission is contributed to the rapid increase in CO_(2) concentration.In the current study the anthropogenic CO_(2) emission in the Middle East(ME)is investigated using 6 years columnaveraged CO_(2) dry air mole fraction(XCO_(2))observation from Orbiting Carbon Observatory-2(OCO-2)satellite.In this way,the XCO_(2) anomaly(DXCO_(2))as the detrended and deseasonalized term of OCO-2XCO_(2) product,was computed and compared to provide the direct spacebased anthropogenic CO_(2) emission monitoring.As a result,the high positive and negative DXCO_(2) values have corresponded to the major sources such as oil and gas industries,and growing seasons over ME,respectively.Consequently,the Open-source Data Inventory for Anthropogenic CO_(2)(ODIAC)emission and the gross primary productivity(GPP)were utilized in exploring the DXCO_(2) relation with human and natural driving factors.The results showed the capability of DXCO_(2) maps in detecting CO_(2) emission fluctuations in defined periods were detectible in daily to annual periods.The simplicity and accuracy of the method in detecting the man-made and natural driving factors including the main industrial areas,megacities,or local changes due to COVID-19 pandemic or geopolitical situations as well as the vegetation absorption and biomass burning is the key point that provides the environmental managers and policymakers with valuable and accessible information to control and ultimately reduce the CO_(2) emission over critical regions.展开更多
文摘Knowledge of decoupling indicators and its determinants is useful for formulating targeted policy recommendations. To this end, the Log-Mean Divisia Index and Tapio models were applied in this paper to study the decoupling relationship among economic growth and GHG emissions in Cameroon over the period 1971-2014. The analyzes were conducted according to the three major periods that marked Cameroon after independence and the decoupling indicators were broken down into seven factors while considering the three main GHGs emitted in this country (i.e. CO2, CH4, and N2O). The results showed that weak decoupling, strong decoupling, and strong negative decoupling occurred in Cameroon during the periods 1971-1984 and 1994-2014 which represent the periods before and after the economic crisis, respectively. In addition to these three decoupling statuses, recessive decoupling only appeared during the economic crisis period (1984-1994). From 1971 to 1984 and between 1994 and 2014, carbon intensity, economic activity, population, and emission factor not only contributed to the increase of Cameroon’s GHG (particularly CO2) emissions but also prevented decoupling. Unlike the period 1984-1994, energy intensity contributed to reducing environmental pollution while promoting decoupling during the periods 1971-1984 and 1994-2014. Although all played an important role in decoupling, we found that after the introduction of natural gas into the country’s energy mix from 2007, the effect of renewable energies on the mitigation of Cameroon’s CO2 emissions remained higher than the substitution of fossil fuels. However, to develop a cleaner economy, Cameroon should maintain modest economic growth and continuously transform economic development pathways, while encouraging the use of renewable energy to further reduce energy intensity per unit of GDP per capita.
基金Supported by National Key Technology Research and Development Program(2013BAD11B03)National Natural Science Foundation(31272249,31071865,41505100)~~
文摘This experiment was conducted in Xinxiang, Henan from June 2013 to June 2014. Total four treatments were designed including farmers ’ common practice （F, 250 kg/hm^2）, 80% F （LF, 200 kg/hm^2）, 80% F＋biochar （LFC） and no fertilizer （CK） to measure the dynamic emissions of CO2 and N2O from a summer maize-winter wheat field by static chamber-gas chromatography method. The results showed that the soil CO2 emission was 21.8-1 022.7 mg/（m^2·h）, and was mainly influenced by soil temperature and moisture content. During the growth of summer maize, the soil CO2 emission was more significantly affected by soil moisture con-tent; and in winter wheat growing season, it was more significantly affected by soil temperature in the top 5 cm. The LF and LFC treatments significantly reduced the soil cumulative CO2 emission, especial y during the growth of winter wheat. Fertiliza-tion and irrigation were the main factors influencing the soil N2O emission. The soil N2O emission during the fertilization period accounted for 73.9%-74.5% and 40.5%-43.6% of the soil cumulative N2O emission during the summer maize-and winter wheat-growing season, respectively. The peak of emission fluxes was determined by fertilization amount, while the occurrence time of emission peak and emission re-duction effect were influenced by irrigation. The LF treatment reduced the soil cu-mulative N2O emission by 15.7%-16.8% and 18.1%-18.5% during the growth period of summer maize and winter wheat, respectively. Reduced nitrogen fertilization is an effective way for reducing N2O emission in intensive high-yielding farmland. Under a suitable nitrogen level （200 kg/hm^2）, the application of biochar showed no significant effect on the soil N2O emission in a short term. The N2O emission factors of the L and LF treatments were 0.60% and 0.56%, respectively. ln the intensive high-yield-ing farmland of North China, reducing the nitrogen application amount is an appro-priate measure to mitigate greenhouse gas emissions without crop yield loss.
基金the CSIROthe Australian Coal Association Research Program
文摘This study discusses a method of quantifying emissions from surface coal mining that has been trialled in Australia. The method is based on direct measurement of surface emissions from uncovered coal seams in mine pits, concurrent measurement of residual gas content of blasted coal in mine pits, and measurement of pre-mining gas content of the same seam from cores retrieved from exploration boreholes drilled away from active mining. The results from one of the mines studied are presented in this paper. In this mine,the pre-mining gas content of the target seam was measured using cores from an exploration borehole away from active mining. Gas content varied from 0.7 to 0.8 m3/t and gas composition varied from16% to 21% CH4(84–79% CO2). In-pit measurements included seam surface emissions and residual gas content of blasted and ripped coal. Residual gas content varied from 0.09 to 0.15 m3/t, less than twofold across the mine pit. Composition of the residual gas was in general 90% CO2and 10% CH4, with slight variation between samples. Coal seam surface emissions varied from 1.03 to 7.50 mL of CO2-e per minute and per square meter of the coal seam surface, a sevenfold variation across the mine pit.
基金financial support by the Ministry of Science and Technology of China (Grant No.2018YFC1509006)the National Natural Science Foundation of China (Grant No.71874096)+1 种基金the Macao SAR Government Higher Education Fundthe Macao University of Science and Technology (Grant No.FRG-19-008-MSB)。
文摘Adipic acid is an important petrochemical product,and its production process emits a high concentration of greenhouse gas N_2 O.This paper aims to provide quantitative references for relevant authorities to formulate greenhouse gas control roadmaps.The forecasting method of this paper is consistent with the published national inventory in terms of caliber.Based on the N_2 O abatement technical parameters of adipic acid and the production trend,this paper combines the scenario analysis and provides a measurement of comprehensive N_2 O abatement effect of the entire industry in China.Four future scenarios are assumed.The baseline scenario(BAUS) is a frozen scenario.Three emission abatement scenarios(ANAS,SNAS,and ENAS) are assumed under different strength of abatement driving parameters.The results show that China's adipic acid production process can achieve increasingly significant N_2 O emission abatement effects.Compared to the baseline scenario,by 2030,the N_2 O emission abatements of the three emission abatement scenarios can reach 207-399 kt and the emission abatement ratios can reach 32.5%-62.6%.By 2050,the N_2 O emission abatements for the three emission abatement scenarios can reach 387-540 kt and the emission abatement ratios can reach 71.4%-99.6%.
基金Supported by the National(Key)Basic Research and Development(973)Program of China(2011CB428605)National Natural Science Foundation of China(41275045 and U1133603)Key Project of the Chinese Academy of Meteorological Sciences(2013Z005)
文摘In this study, comparison of model results and satellite observations reveals that the Whole-Atmosphere Community Climate Model （WACCM-3） reasonably well reproduced the distributions and seasonal vari- ations of C10 and HC1 concentrations. In three greenhouse gas emission scenarios （A1B, A2, and B1）, the C10, C1, C1ONO2, and HC1 concentrations would gradually decrease with time as emissions of ozone depleting substances （ODS） steadily decrease. The rates of the changes in the C10, C1, C1ONO2, and HC1 concentrations are different in the same emission scenario and the rates of change in the same composition concentration are different for different emission scenarios. The C10, C1, and C1ONO2 concentrations de- crease fastest in scenario A2, next fastest in scenario A1B, and slowest in scenario B1. In contrast, the HC1 concentration decreases fastest in scenario B1. The ozone concentration recovers quickly, and is highest in scenario A2. The results show that a rapid decrease in the C10 concentration is an important reason for the accelerated recovery of the ozone layer in scenario A2.
基金supported by the Project of Development of Methane Concen-tration Technology Aimed at Effective Use of Low-concentration CMM (Coal Methane Gas)the International Research Cooperation Project Implemented by the New Energy and Industrial Technology Development Organizationthe Cooperative Research Project Subsidies from the Ministry of Economy,Trade and Industry
文摘In coal mines in such countries as China and Russia,most of the coal mine methane(CMM) generated during mining is emitted to the atmosphere without any effective usage,because the methane concentration of CMM is relatively low and not allowed to be used as fuel for safety reasons.Methane is one of the greenhouse gases.Therefore,if it becomes possible to concentrate CMM to an acceptable level for use as fuel,this will greatly contribute to reduction of greenhouse gas emissions.With the aim of gaining approval as a greenhouse gas emission reduction of the clean development mechanism(CDM) or joint implementation(JI) project,we developed a CMM concentration system to apply the vacuum pressure swing adsorption(VPSA) technology using a high methane-selective adsorbent by Osaka Gas Co.,Ltd.The pilot-scale plant of a CMM concentration system was installed in a coal mine in Fuxin City in the northeastern China and a demonstration test was commenced in December 2008.As the result,the pilot-scale plant successfully concentrated the raw material gas with a methane concentration of 21% and a flow rate of 1000 Nm3/h to 48%,which exceeded the target of the methane concentration performance(a 25% increase).The methane recovery rate reached 93%.
基金Item Sponsored by Natural Science and Engineering Research Council of Canada (NSERC) (326868-06)
文摘The global steel production has been growing for the last 50 years, from 200 Mt in 1950s to 1 240 Mt in 2006. Iron and steel making industry is one of the most energy-intensive industries, with an annual energy consumption of about 24 EJ, 5% of the world＇s total energy consumption. The steel industry accounts for 3%-4% of totat world greenhouse gas emissions. Enhancing energy efficiency and employing energy saving/recovering technologies such as coke dry quechning （CDQ） and top pressure recovery turbine （TRT） can be short-term approaches to the steel industry to reduce greenhouse gas emission. The long-term approaches to achieving a significant reduction in CO2 emissions from the steel industry would be through developing and applying CO2 breakthrough technologies for iron and steel making, and：through increasing use of renewable energy for iron and steel making. Thus, an overview of new CO2 breakthrough technologies for iron and steel making was made.
基金supported by the Ministry of Ecology and Environment of the People’s Republic of China(No.2110105)Guangdong Basic and Applied Basic Research Foundation(No.2019A1515011757)the Graduate Innovation Project of China University of Petroleum(East China)(No.YCX2021055)。
文摘Petrochemical enterprises have become a major source of global greenhouse gas(GHG)emissions.Yet,due to the unavailability of basic data,there is still a lack of case studies to quantify GHG emissions and provide petrochemical enterprises with guidelines for implementing energy conservation and emission reduction strategies.Therefore,this study conducted a life cycle assessment(LCA)analysis to estimate the GHG emissions of four typical petrochemical enterprises in China,using first-hand data,to determine possible emission reduction measures.The analytical data revealed that Dushanzi Petrochemical(DSP)has the highest GHG emission intensity(1.17 tons CO_(2)e/ton),followed by Urumqi Petrochemical(UP)(1.08 tons CO_(2)e/ton),Dalian Petrochemical(DLP)(average 0.58 tons CO_(2)e/ton)and Karamay Petrochemical(KP)(average 0.50 tons CO_(2)e/ton)over the whole life cycle.At the same time,GHG emissions during fossil fuel combustion were the largest contributor to the whole life cycle,accounting for about 77.31%–94.27% of the total emissions.In the fossil-fuel combustion phase,DSP had the highest unit GHG emissions(1.20 tons CO_(2)e),followed by UP(0.89 tons CO_(2)e).In the industrial production phase,DLP had the highest unit GHG emissions(average 0.13 tons CO_(2)e/ton),followed by UP(0.10 tons CO_(2)e/ton).During the torch burning phase,torch burning under accident conditions was the main source of GHG emissions.It is worth noting that the CO_(2) recovery stage has"negative value,"indicating that it will bring some environmental benefits.Further scenario analysis shows that effective policies and advanced technologies can further reduce GHG emissions.
文摘The work is a case study of a cruise ship supplied by liquefied natural gas(LNG)and equipped with a solid oxide fuel cell(SOFC).It is supposed that a 20 MW SOFC plant is installed on-board to supply hotel loads and assisting three dual-fuel(DF)diesel/LNG generator sets.LNG consumption and emissions are estimated both for the SOFC plant and DF generator sets.It results that the use of LNG-SOFC plant in comparison to DF generator sets allows to limit significantly the SO_(x),CO,NO_(x),PM emissions and to reduce the emission of CO_(2)by about 11%.A prediction of the weight and volume of the SOFC plant is conducted and a preliminary modification of the general arrangement of the cruise ship is suggested,according to the latest international rules.It results that the SOFC plant is heavier and occupies more volume on board than a DF gen-set;nevertheless,these features do not affect the floating and the stability of the cruise ship.
基金supported by the National Basic Research Program of China (2012CB417106)the National Natural Science Foundation of China (41171212)
文摘Agricultural soils are deficient of phosphorus （P） worldwide. Phosphatic fertilizers are therefore applied to agricultural soils to improve the fertility and to increase the crop yield. However, the effect of phosphorus application on soil N2O emissions has rarety been studied. Therefore, we conducted a laboratory study to investigate the effects P addition on soil N2O emissions from P deficient alluvial soil under two levels of nitrogen （N） fertilizer and soil moisture. Treatments were arranged as follows： P （0 and 20 mg P kg-1） was applied to soil under two moisture levels of 60 and 90% water filled pore space （WFPS）. Each P and moisture treatment was further treated with two levels of N fertilizer （0 and 200 mg N kg-1 as urea）. Soil variables including mineral nitrogen （NH4＋-N and NO3--N）, available P, dissolved organic carbon （DOC）, and soil N2O emissions were measured throughout the study period of 50 days. Results showed that addition of P increased N2O emis- sions either under 60% WFPS or 90% WFPS conditions. Higher N2O emissions were observed under 90% WFPS when compared to 60% WFPS. Application of N fertilizer also enhanced N2O emissions and the highest emissions were 141 μg N2O kg-1 h-1 in P＋N treatment under 90% WFPS. The results of the present study suggest that P application markedly increases soil N2O emissions under both low and high soil moisture levels, and either with or without N fertilizer application.
基金Under the auspices of the National Key Research & Development Program of China(No.2017YFA0604700)
文摘Market-based emission trading schemes(ETSs) are widely used in the developed world to reduce greenhouse gas(GHG) emissions which are perceived as the source of global climate change. China, as the largest GHG emitter in the world, is committed to introducing an ETS to reduce emissions. Here we reviewed existing ETSs and sustainable energy policies worldwide as well as China's pilot programs. These studies were conducted in order to propose recommendations for national initiatives and strategies to be implemented in China in relation to climate change adaptation and mitigation. It has been shown that setting emission caps in the context of a national emission intensity target is difficult. However, implementing reliable systems for measurement, reporting, and verification of emissions are essential. A two-level management system(by central and provincial governments) for carbon trading is beneficial to ensure uniform standards and compliance while maintaining flexibility. Persistent political support from, and effective coordination of, policies by the government are crucial. In addition, strengthening of institutional innovation, and the establishment of a national GHG emissions information system, are of equal importance. This vital information could provide a great opportunity for China to re-define its economic growth and take global leadership in combatting climate change.
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.
基金supported by the National Key Research and Development Program of China(No.2017YFD0300105)the National Natural Science Foundation of China(No.41877325)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2018349)。
文摘Elevated CO_(2)(eCO_(2))and rice cultivars can strongly alter CH_(4)and N_(2)O emissions from paddy fields.However,detailed information on how their interaction affects greenhouse gas fluxes in the field is still lacking.In this study,we investigated CH_(4)and N_(2)O emissions and rice growth under two contrasting rice cultivars(the strongly and weakly responsive cultivars)in response to eCO_(2),200μmol mol^(-1)higher than the ambient CO_(2)(aCO_(2)),in Chinese subtropical rice systems relying on a multi-year in-situ free-air CO_(2)enrichment platform from 2016 to 2018.The results showed that compared to aCO_(2),eCO_(2)increased rice yield by 7%-31%,while it decreased seasonal cumulative CH_(4)and N_(2)O emissions by 10%-59%and 33%-70%,respectively,regardless of rice cultivar.The decrease in CH_(4) emissions under eCO_(2)was possibly ascribed to the lower CH_(4)production potential(MPP)and the higher CH_(4)oxidation potential(MOP)correlated with the higher soil redox potential(Eh)and O_(2)concentration([O_(2)])in the surface soil.The mitigating effect of eCO_(2)on N_(2)O emissions was likely associated with the reduction of soil soluble N content.The strongly responsive cultivars had lower CH_(4)and N_(2)O emissions than the weakly re sponsive cultivars,and the main reason might be that the former induced higher soil Eh and[O_(2)]in the surface soil and had larger plant biomass and greater N uptake.The findings indicated that breeding strongly responsive cultivars with the potential for greater rice production and lower greenhouse gas emissions is an effective agricultural practice to ensure food security and environmental sustainability under future climate change scenarios.
基金funded by the International Atomic Energy Agency through a Coordinated Research Project(CRP D1.50.16)“Minimizing Farming Impacts on Climate Change by Enhancing Carbon and Nitrogen Capture and Storage in Agro-Ecosystems”(18595)of Soil and Water Management and Crop Nutrition Section,Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture,Department of Nuclear Sciences and Applications。
文摘Nitrification inhibitors are widely used in agriculture to mitigate nitrous oxide(N_(2)O)emission and increase crop yield.However,no concrete information on their mitigation of N_(2)O emission is available under soil and environmental conditions as in Pakistan.A field experiment was established using a silt clay loam soil from Peshawar,Pakistan,to study the effect of urea applied in combination with a nitrification inhibitor,nitrapyrin(2-chloro-6-tri-chloromethyl pyridine),and/or a plant growth regulator,gibberellic acid(GA_3),on N_(2)O emission and the nitrogen(N)uptake efficiency of maize.The experimental design was a randomized complete block with five treatments in four replicates:control with no N(CK),urea(200 kg N ha^(-1))alone,urea in combination with nitrapyrin(700 g ha^(-1)),urea in combination with GA_3(60 g ha^(-1)),and urea in combination with nitrapyrin and GA_3.The N_(2)O emission,yield,N response efficiency,and total N uptake were measured during the experimental period.The treatment with urea and nitrapyrin reduced total N_(2)O emission by 39%–43%and decreased yield-scaled N_(2)O emission by 47%–52%,relative to the treatment with urea alone.The maize plant biomass,grain yield,and total N uptake increased significantly by 23%,17%,and 15%,respectively,in the treatment with urea and nitrapyrin,relative to the treatment with urea alone,which was possibly due to N saving,lower N loss,and increased N uptake in the form of ammonium;they were further enhanced in the treatment with urea,nitrapyrin,and GA_3 by 27%,36%,and 25%,respectively,probably because of the stimulating effect of GA_3 on plant growth and development and the reduction in biotic and abiotic stresses.These results suggest that applying urea in combination with nitrapyrin and GA_3 has the potential to mitigate N_(2)O emission,improve N response efficiency,and increase maize yield.
基金supported by Department of Geography and Earth Sciences(DGES)and Institute of Biological,Environmental and Rural Sciences(IBERS)at Aberystwyth University,Wales of UK。
文摘Seasonally flooded várzea forests of Western Amazonia are one of the most productive and biodiverse wetland forests in the world.However,data on their soil CO_(2)emissions,soil organic matter decomposition rates,and soil C stocks are scarce.This is a concern because hydrological changes are predicted to lead to increases in the height,extent,and duration of seasonal floods,which are likely to have a significant effect on soil C stocks and fluxes.However,with no empirical data,the impact of altered flood regimes on várzea soil C cycles remains uncertain.This study quantified the effects of maximum annual flood height and soil moisture on soil CO_(2)efflux rate(R_(s))and soil organic matter decomposition rate(k)in the várzea forests of Pacaya Samiria National Reserve,Peru.The study was conducted between May and August 2017.The results showed that R_(s)(10.6–182.7 mg C m^(-2)h^(-1))and k(0.016–0.078)varied between and within sites,and were considerably lower than the values reported for other tropical forests.In addition,R_(s)was negatively affected by flood height(P<0.01)and soil moisture(P<0.001),and it decreased with decreasing river levels post flooding(P<0.001).In contrast,k was not affected by any of the above-mentioned factors.Soil moisture was the dominant factor influencing R_(s),and it was significantly affected by maximum flood height,even after the floods had subsided(P<0.001).Consequently,we concluded that larger floods will likely lead to reduced R_(s),whilst k could remain unchanged but with decomposition processes becoming more anaerobic.
文摘The anthropogenic CO_(2) emission is contributed to the rapid increase in CO_(2) concentration.In the current study the anthropogenic CO_(2) emission in the Middle East(ME)is investigated using 6 years columnaveraged CO_(2) dry air mole fraction(XCO_(2))observation from Orbiting Carbon Observatory-2(OCO-2)satellite.In this way,the XCO_(2) anomaly(DXCO_(2))as the detrended and deseasonalized term of OCO-2XCO_(2) product,was computed and compared to provide the direct spacebased anthropogenic CO_(2) emission monitoring.As a result,the high positive and negative DXCO_(2) values have corresponded to the major sources such as oil and gas industries,and growing seasons over ME,respectively.Consequently,the Open-source Data Inventory for Anthropogenic CO_(2)(ODIAC)emission and the gross primary productivity(GPP)were utilized in exploring the DXCO_(2) relation with human and natural driving factors.The results showed the capability of DXCO_(2) maps in detecting CO_(2) emission fluctuations in defined periods were detectible in daily to annual periods.The simplicity and accuracy of the method in detecting the man-made and natural driving factors including the main industrial areas,megacities,or local changes due to COVID-19 pandemic or geopolitical situations as well as the vegetation absorption and biomass burning is the key point that provides the environmental managers and policymakers with valuable and accessible information to control and ultimately reduce the CO_(2) emission over critical regions.
