Using the SWOT analysis method,this paper analyzed the internal strengths,weaknesses,external opportunities and threats of forest carbon sink projects in Yunnan Province.It found that Yunnan Province has strengths in ...Using the SWOT analysis method,this paper analyzed the internal strengths,weaknesses,external opportunities and threats of forest carbon sink projects in Yunnan Province.It found that Yunnan Province has strengths in economic environment and practical experience,weaknesses in social participation,project scale and carbon sink talents,opportunities in international climate environment,domestic policies,etc.,and threats in project crediting period and forest resource protection,etc.In view of these,Yunnan Province can change the participation mode of forest carbon sink projects,adopt appropriate trading methods,get familiar with the relevant rules of forest carbon sink projects,strengthen the publicity and research of forest carbon sink theory,strengthen the management of carbon sink forests and expand forest carbon sink projects to enhance the market competitiveness of the Yunnan forest carbon sink projects.展开更多
Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban...Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban forests and improvement of function.To clarify the effect of two forest types with different urbanization intensities,we determined differences in vegetation composition and diversity,structural traits,and carbon stocks of 152 plots(20 m×20 m)in urban park forests in Changchun,which had the largest green quantity and carbon density effectiveness.We found that 1.1-fold thicker and healthier trees,and 1.6-to 2.0-fold higher,healthier,denser,and more various shrubs but with sparser trees and herbs occurred in the central urban forests(p<0.05)than in the outer forests.The conifer forests exhibited 30–70%obviously higher tree aboveground carbon sequestration(including stem and leaf)and 20%bigger trees,especially in the outer forests(p<0.05).In contrast,1.1-to 1.5-fold higher branch stocks,healthier and more diverse trees were found in broadleaved forests of both the inner and outer forests(p<0.05).Plant size and dominant species had similarly important roles in carbon stock improvement,especially big-sized woody plants and Pinus tabuliformis.In addition,a higher number of deciduous or needle species positively affected the broadleaved forest of the central urban area and conifer forest of the outer urban area,respectively.These findings can be used to guide precise management and accelerate the improvement of urban carbon function in Northeast China in the future.展开更多
Since China announced its goal of becoming carbon-neutral by 2060, carbon neutrality has become a major target in the development of China's urban agglomerations. This study applied the Future Land Use Simulation(...Since China announced its goal of becoming carbon-neutral by 2060, carbon neutrality has become a major target in the development of China's urban agglomerations. This study applied the Future Land Use Simulation(FLUS) model to predict the land use pattern of the ecological space of the Beibu Gulf urban agglomeration, in 2060 under ecological priority, agricultural priority and urbanized priority scenarios. The Integrated Valuation of Ecosystem Services and Trade-offs(In VEST) model was employed to analyse the spatial changes in ecological space carbon storage in each scenario from 2020 to 2060. Then, this study used a Geographically Weighted Regression(GWR) model to determine the main driving factors that influence the changes in land carbon sinking capacity. The results of the study can be summarised as follows: firstly, the agricultural and ecological priority scenarios will achieve balanced urban expansion and environmental protection of resources in an ecological space. The urbanized priority scenario will reduce the carbon sinking capacity. Among the simulation scenarios for 2060, carbon storage in the urbanized priority scenario will decrease by 112.26 × 10^(6) t compared with that for 2020 and the average carbon density will decrease by 0.96 kg/m^(2) compared with that for 2020. Carbon storage in the agricultural priority scenario will increase by 84.11 × 10^(6) t, and the average carbon density will decrease by 0.72 kg/m^(2). Carbon storage in the ecological priority scenario will increase by 3.03 × 10^(6) t, and the average carbon density will increase by 0.03 kg/m^(2). Under the premise that the population of the town will increases continuously, the ecological priority development approach may be a wise choice.Secondly, slope, distance to river and elevation are the most important factors that influence the carbon sink pattern of the ecological space in the Beibu Gulf urban agglomeration, followed by GDP, population density, slope direction and distance to traffic infrastructure.At the same time, urban space expansion is the main cause of the changes of this natural factors. Thirdly, the decreasing trend of ecological space is difficult to reverse, so reasonable land use policy to curb the spatial expansion of cities need to be made.展开更多
Climate change is currently the biggest environmental challenge facing sustainable development in human society,and it is an inherent requirement for achieving sustainable development by actively addressing climate ch...Climate change is currently the biggest environmental challenge facing sustainable development in human society,and it is an inherent requirement for achieving sustainable development by actively addressing climate change.Under the increasingly strict constraints of climate governance,developed countries such as the United States,European Union countries,and Japan have responded and actively formulated low-carbon development goals and policy measures that are in line with their national conditions.These policies mainly involve various fields such as low-carbon technology,energy conservation and emission reduction,and circular development,with clear policy guidance.In this paper,the evolution of policies on marine carbon sink and carbon trading in China is summarized,providing support for better understanding the background of formulating relevant international and domestic policies.展开更多
Climate change is currently the biggest environmental challenge facing sustainable development in human society,and an inherent requirement for achieving sustainable development is actively addressing climate change.U...Climate change is currently the biggest environmental challenge facing sustainable development in human society,and an inherent requirement for achieving sustainable development is actively addressing climate change.Under the increasingly strict constraints of climate governance,developed countries such as the United States,European Union countries,and Japan have responded and actively formulated low-carbon development goals and policy measures that are in line with their national conditions.These policies mainly involve various fields such as low-carbon technology,energy conservation and emission reduction,and circular development,with clear policy guidance.In this paper,the evolution of policies on marine carbon sink and carbon trading in developed countries such as the United States and Europe is summarized,providing support for a better understanding of the background of international and domestic policy formulation.展开更多
[Objectives]To analyze the relationship between the land use pattern and the carbon sequestration level of the ecosystem vegetation in Kunming City,and to provide a certain reference for optimizing the land ecological...[Objectives]To analyze the relationship between the land use pattern and the carbon sequestration level of the ecosystem vegetation in Kunming City,and to provide a certain reference for optimizing the land ecological use pattern and scientific carbon reduction and sequestration.[Methods]Based on remote sensing data,meteorological data,vegetation data and soil data,the Carnegie-Ames-Stanford Approach(CASA)was adopted to estimate the vegetation net primary productivity(NPP)in Kunming during 2005-2020,and then the vegetation carbon sink was calculated through the plant mortality model.Besides,it established the land use transfer matrix of Kunming City,and analyzed the change characteristics of the carbon sink of ecosystem vegetation in Kunming City under the influence of land use changes.[Results]During 2005-2020,the water area,construction land and unused land area in Kunming increased by 43.52,710.51 and 2.8 km 2,respectively;farmland,woodland and grassland decreased by 269.72,140.20 and 347.03 km 2,respectively;farmland,woodland,grassland,water area,construction land and unused land caused a total of 58212.72 t of vegetation net carbon sink loss in land conversion,accounting for 14.88%,25.23%,11.95%,10.58%,37.09%,and 0.26%,respectively.[Conclusions]This study is expected to help to improve the ecological carbon sequestration capacity of Kunming and promote the sustainable development of land resources.展开更多
The conversion of CO2 into H+ and is a relatively slow reaction. Hence, its kinetics may be rate determining in carbonate rock dissolution. Carbonic anhydrase (CA), which is widespread in nature, was used to catalyze ...The conversion of CO2 into H+ and is a relatively slow reaction. Hence, its kinetics may be rate determining in carbonate rock dissolution. Carbonic anhydrase (CA), which is widespread in nature, was used to catalyze the CO2 conversion process in dissolution experiments of limestone and dolomite. It was found that the rate of dissolution increases by a factor of about 10 after the addition of CA at a high CO2 partial pressure (Pco2) for limestone and about 3 at low Pco2 for dolomite. This shows that reappraisal is necessary for the importance of chemical weathering (including carbonate rock dissolution and silicate weathering) in the atmospheric CO2 sink and the mysterious missing sink in carbon cycling. It is doubtless that previous studies of weathering underestimated weathering rates due to the ignorance of CA as an activator in weathering, thus the contribution of weathering to the atmospheric CO2 sink is also underestimated. This finding also shows the need to examine the situ distribution and activity of CA in different waters and to investigate the role of CA in weathering.展开更多
Wetlands play an important role in the global carbon cycle, but there are still considerable uncertainties in the estimation of wetland carbon storage and a dispute on whether wetlands are carbon sources or carbon sin...Wetlands play an important role in the global carbon cycle, but there are still considerable uncertainties in the estimation of wetland carbon storage and a dispute on whether wetlands are carbon sources or carbon sinks. Xiaoxing’anling are one of several concentrated distribution areas of forested wetland in China, but the carbon storage and carbon sink/source of forested wetlands in this area is unclear. We measured the ecosystem carbon storage (vegetation and soil), annual net carbon sequestration of vegetation and annual carbon emissions of soil heterotrophic respiration of five typical forested wetland types (alder swamp, white birch swamp, larch swamp, larch fen, and larch bog) distributed along a moisture gradient in this area in order to reveal the spatial variations of their carbon storage and quantitatively evaluate their position as carbon sink or source according to the net carbon balance of the ecosystems. The results show that the larch fen had high carbon storage (448.8 t ha^(−1)) (6.8% higher than the larch bog and 10.5–30.1% significantly higher than other three wetlands (P < 0.05), the white birch swamp and larch bog were medium carbon storage ecosystems (406.3 and 420.1 t ha^(−1)) (12.4–21.8% significantly higher than the other two types (P < 0.0 5), while the alder swamp and larch swamp were low in carbon storage (345.0 and 361.5 t ha^(−1), respectively). The carbon pools of the five wetlands were dominated by their soil carbon pools (88.5–94.5%), and the vegetation carbon pool was secondary (5.5–11.5%). At the same time, their ecosystem net carbon balances were positive (0.1–0.6 t ha^(−1) a^(−1)) because the annual net carbon sequestration of vegetation (4.0–4.5 t ha^(−1) a^(−1)) were higher than the annual carbon emissions of soil heterotrophic respiration (CO_(2) and CH_(4)) (3.8–4.4 t ha^(−1) a^(−1)) in four wetlands, (the alder swamp being the exception), so all four were carbon sinks while only the alder swamp was a source of carbon emissions (− 2.1 t ha^(−1) a^(−1)) due to a degraded tree layer. Our results demonstrate that these forested wetlands were generally carbon sinks in the Xiaoxing’anling, and there was obvious spatial variation in carbon storage of ecosystems along the moisture gradient.展开更多
The values of forest carbon stock (CSV) and carbon sink (COV) are important topics in the global carbon cycle. We quantitatively analyzed the factors affecting changes in both for forest ecosystem in 2000−2015. With m...The values of forest carbon stock (CSV) and carbon sink (COV) are important topics in the global carbon cycle. We quantitatively analyzed the factors affecting changes in both for forest ecosystem in 2000−2015. With multiple linear stepwise regression analysis, we obtained the factors that had a significant impact on changes of CSV and COV, and then the impacts of these variables on CSV and COV were used for further quantitative analysis using the vector autoregressive model. Our results indicated that both stand age and afforestation area positively affect CSV and COV;however, the forest enterprise gross output value negatively affects CSV. Stand age has the largest long-term cumulative impact on CSV and COV, reaching 40.4% and 9.8%, respectively. The impact of enterprise gross output value and afforestation area on CSV and COV is the smallest, reaching 4.0% and 0.3%, respectively.展开更多
The measurement of atmospheric O_(2)concentrations and related oxygen budget have been used to estimate terrestrial and oceanic carbon uptake.However,a discrepancy remains in assessments of O_(2)exchange between ocean...The measurement of atmospheric O_(2)concentrations and related oxygen budget have been used to estimate terrestrial and oceanic carbon uptake.However,a discrepancy remains in assessments of O_(2)exchange between ocean and atmosphere(i.e.air-sea O_(2)flux),which is one of the major contributors to uncertainties in the O_(2)-based estimations of the carbon uptake.Here,we explore the variability of air-sea O_(2)flux with the use of outputs from Coupled Model Intercomparison Project phase 6(CMIP6).The simulated air-sea O_(2)flux exhibits an obvious warming-induced upward trend(~1.49 Tmol yr−2)since the mid-1980s,accompanied by a strong decadal variability dominated by oceanic climate modes.We subsequently revise the O_(2)-based carbon uptakes in response to this changing air-sea O_(2)flux.Our results show that,for the 1990−2000 period,the averaged net ocean and land sinks are 2.10±0.43 and 1.14±0.52 GtC yr−1 respectively,overall consistent with estimates derived by the Global Carbon Project(GCP).An enhanced carbon uptake is found in both land and ocean after year 2000,reflecting the modification of carbon cycle under human activities.Results derived from CMIP5 simulations also investigated in the study allow for comparisons from which we can see the vital importance of oxygen dataset on carbon uptake estimations.展开更多
It is recognized that karst processes are actively involved in the current global carbon cycle based on twenty years research,and the carbon sink occurred in karst processes is possibly an important part of“missing s...It is recognized that karst processes are actively involved in the current global carbon cycle based on twenty years research,and the carbon sink occurred in karst processes is possibly an important part of“missing sink”in global carbon cycle.In this paper,an overview is given on karst carbon cycle research,and influence factors,formed carbon pools(background carbon sink)and sink increase potentials of current karst carbon cycle are analyzed.Carbonate weathering could contribute to the imbalance item(BIM)and land use change item(ELUC)in the global carbon cycle model,owing to its uptake of both atmospheric CO_(2)(carbon sink effect)and CO_(2) produced by soil respiration(carbon source reduction effect).Karst carbon sink includes inorganic carbon sink resulted from hydrogeochemical process and organic carbon sink generated by aquatic photosynthetic DIC conversion,forming relatively stable river(reservoir)water body or sediment carbon sink.The sizes of both sinks are controlled by terrestrial ecosystems and aquatic ecosystems,respectively.Desertification rehabilitation and carbon sequestration by aquatic plants are two effective ways to increase the carbon sink in karst area.It is estimated that the rate of carbon sink is at least 381000 t CO_(2)/a with vegetation restoration and afforestation in southwest China karst area,while the annual organic carbon sink generated by aquatic photosynthesis is about 84200 t C in the Pearl River Basin.The development of a soil CO_(2) based model for assessment of regional dissolution intensity will help to improve the estimation accuracy of carbon sink increase and potential,thus provide a more clear and efficient karst sink increase scheme and pathway to achieve the goals of“double carbon”.With the deep investigation on karst carbon cycle,mechanism and carbon sink effect,and the improvement of watershed carbon sink measurement methods and regional sink increase evaluation approaches.Karst carbon sink is expected to be included in the list of atmospheric CO_(2) sources/sinks of the global carbon budget in the near future.展开更多
Heavy metal pollution in karst mountainous area of Guizhou has spread due to the long-term exploitation of mineral resources and the improper disposal of environmentally hazardous waste. Heavy metals are characterised...Heavy metal pollution in karst mountainous area of Guizhou has spread due to the long-term exploitation of mineral resources and the improper disposal of environmentally hazardous waste. Heavy metals are characterised by non-degradation, strong toxicity, and constant accumulation, posing a grave threat to karst mountain fragile soil ecosystem. To reduce the harm caused by heavy metal pollution and damage to agricultural products, research was undertaken on the basis of previous work by simulating pot experiments on pak choi cabbage(Brassica rapa chinensis)planted in Cd-contaminated soil: different amounts of organic mineral fertilisers(OMF) compared with chemical fertiliser(CF) were used and by detecting the amount of heavy metal in the mature vegetable, a better fertilisation strategy was developed. The results showed that the Cd content in vegetables grown with CF was 23.70 mg/kg,while that of vegetables grown with OMF and bacterial inoculant was the lowest at 15.13 mg/kg. This suggests that the use of OMF and microbes in karst areas not only promotes plant growth but also hinders plant absorption of heavy metal ions in the soil. In addition, through the collection of pot leachate, the detection of water chemistrycharacteristics, and the calculation of the calcite saturation index, it was found that the OMF method also induces certain carbon sink effects. The results provide a new way in which rationalise the use of OMFs in karst areas to alleviate soil heavy metal pollution and increase soil carbon sequestration.展开更多
As a consequence of global warming and rising sea levels, the oceans are becoming a matter of concern for more and more people because these changes will impact the growth of living organisms as well as people's l...As a consequence of global warming and rising sea levels, the oceans are becoming a matter of concern for more and more people because these changes will impact the growth of living organisms as well as people's living standards. In particular, it is extremely important that the oceans absorb massive amounts of carbon dioxide. This paper takes a pragmatic approach to analyzing the oceans with respect to the causes of discontinuities in oceanic variables of carbon dioxide sinks. We report on an application of chemical, physical and biological methods to analyze the changes of carbon dioxide in oceans. Based on the relationships among the oceans, land, atmosphere and sediment with respect to carbon dioxide, the foundation of carbon dioxide in shell-building and ocean acidification, the changes in carbon dioxide in the oceans and their impact on climate change, and so on, a vital conclusion can be drawn from this study. Specifically, under the condition that the oceans are not disturbed by external forces, the oceans are a large carbon dioxide sink. The result can also be inferred by the formula: C=A-B and G=E+F when the marine ecosystem can keep a natural balance and the amount of carbon dioxide emission is limited within the carrying capacity of the oceans.展开更多
This study explored the ecological effects of the transformation of carbon source and carbon sink in wetlands, that were discussed from four aspects: atmosphere, ocean, plants and soil. The results showed that the wet...This study explored the ecological effects of the transformation of carbon source and carbon sink in wetlands, that were discussed from four aspects: atmosphere, ocean, plants and soil. The results showed that the wetland changed from carbon sink to carbon source, which led to the increase of CO_2 emissions in the atmosphere and the intensification of greenhouse effect, which made the earth face the threat of global warming. At the same time, the content of CO_2 in seawater is increased; the pH value of seawater decreases; the balance of seawater acid-base is destroyed; and the ocean acidification is caused.展开更多
An actively water-cooled limiter has been designed for the long pulse operation of an HT-7 device, by adopting an integrated structure-doped graphite and a copper alloy heat sink with a super carbon sheet serving as a...An actively water-cooled limiter has been designed for the long pulse operation of an HT-7 device, by adopting an integrated structure-doped graphite and a copper alloy heat sink with a super carbon sheet serving as a compliant layer between them. The behaviors of the integrated structure were evaluated in an electron beam facility under different heat loads and cooling conditions. The surface temperature and bulk temperature distribution were carefully measured by optical pyrometers and thermocouples under a steady state heat flux of 1 to 5 MW/m2 and a water flow rate of 3 m3/h, 4.5 m3/h and 6 m3/h, respectively. It was found that the surface temperature increased rapidly with the heat flux rising, but decreased only slightly with the water flow rate rising. The surface temperature reached approximately 1200℃ at 5 MW/m2 of heat flux and 6 ms/h of water flow. The primary experimental results indicate that the integrated design meets the requirements for the heat expelling capacity of the HT-7 device. A set of numerical simulations was also completed, whose outcome was in good accord with the experimental results.展开更多
In recent years,there are research findings of haze formation in various fields of academic circle. It has proved that causes of haze take on diverse characteristics. Thus,from both the natural and human perspective,h...In recent years,there are research findings of haze formation in various fields of academic circle. It has proved that causes of haze take on diverse characteristics. Thus,from both the natural and human perspective,haze governance should be diverse. Research conclusions on causes of haze formation mainly focus on special geographical structure,and meteorological factors such as relatively stable atmosphere,high rate of calm wind,high relative humidity and temperature of air,and human factors such as industrial pollution,automotive exhaust emissions,aerosol pollution,eutrophication of soil water,and change of city underlying surface. Carbon sink mode is a new channel for haze governance.In carbon sink mode,it is feasible to regulate relative humidity and temperature in air,enhance global wind,and reduce fine particles and microorganisms of air pollution,so as to reduce haze pollution. Besides,China's special potential of carbon sink market makes it possible to govern haze on the base of carbon sink.展开更多
Remote sensing image data of typical mining areas in the Loess Plateau from 1986 to 2018 were used to analyze the evolution of land use,explore the division of carbon sink functional areas,and propose carbon neutralit...Remote sensing image data of typical mining areas in the Loess Plateau from 1986 to 2018 were used to analyze the evolution of land use,explore the division of carbon sink functional areas,and propose carbon neutrality paths to provide a reference for the coal industry carbon peak,carbon-neutral action plan.Results show that(1)land use has changed signifcantly in the Pingshuo mining area over the past 30 years.Damaged land in industrial,opencast,stripping,and dumping areas comprises 4482.5 ha of cultivated land,1648.13 ha of grassland,and 963.49 ha of forestland.(2)The carbon sink functional areas of the Pingshuo mining land is divided into invariant,enhancement,low carbon optimization,and carbon emission control areas.The proportion of carbon sinks in the invariant area is decreasing,whereas the proportion in enhancement,low carbon optimization,and carbon emission control areas is gradually increasing.(3)The carbon neutrality of the mining area must be reduced from the entire process of stripping–mining–transport–disposal–reclamation,and carbon emissions and carbon sink accounting must start from the life cycle of coal resources.Therefore,carbon neutrality in mining areas must follow the 5R principles of reduction,reuse,recycling,redevelopment,and restoration,and attention must be paid to the potential of carbon sinks in ecological protection and restoration projects in the future.展开更多
文摘Using the SWOT analysis method,this paper analyzed the internal strengths,weaknesses,external opportunities and threats of forest carbon sink projects in Yunnan Province.It found that Yunnan Province has strengths in economic environment and practical experience,weaknesses in social participation,project scale and carbon sink talents,opportunities in international climate environment,domestic policies,etc.,and threats in project crediting period and forest resource protection,etc.In view of these,Yunnan Province can change the participation mode of forest carbon sink projects,adopt appropriate trading methods,get familiar with the relevant rules of forest carbon sink projects,strengthen the publicity and research of forest carbon sink theory,strengthen the management of carbon sink forests and expand forest carbon sink projects to enhance the market competitiveness of the Yunnan forest carbon sink projects.
基金the Youth Growth Technology Project,Science and Technology Department of Jilin Province(20230508130RC)Bureau of Forestry and Landscaping of Changchun.
文摘Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban forests and improvement of function.To clarify the effect of two forest types with different urbanization intensities,we determined differences in vegetation composition and diversity,structural traits,and carbon stocks of 152 plots(20 m×20 m)in urban park forests in Changchun,which had the largest green quantity and carbon density effectiveness.We found that 1.1-fold thicker and healthier trees,and 1.6-to 2.0-fold higher,healthier,denser,and more various shrubs but with sparser trees and herbs occurred in the central urban forests(p<0.05)than in the outer forests.The conifer forests exhibited 30–70%obviously higher tree aboveground carbon sequestration(including stem and leaf)and 20%bigger trees,especially in the outer forests(p<0.05).In contrast,1.1-to 1.5-fold higher branch stocks,healthier and more diverse trees were found in broadleaved forests of both the inner and outer forests(p<0.05).Plant size and dominant species had similarly important roles in carbon stock improvement,especially big-sized woody plants and Pinus tabuliformis.In addition,a higher number of deciduous or needle species positively affected the broadleaved forest of the central urban area and conifer forest of the outer urban area,respectively.These findings can be used to guide precise management and accelerate the improvement of urban carbon function in Northeast China in the future.
基金Under the auspices of National Natural Science Foundation of China (No. 52268008, 51768001)。
文摘Since China announced its goal of becoming carbon-neutral by 2060, carbon neutrality has become a major target in the development of China's urban agglomerations. This study applied the Future Land Use Simulation(FLUS) model to predict the land use pattern of the ecological space of the Beibu Gulf urban agglomeration, in 2060 under ecological priority, agricultural priority and urbanized priority scenarios. The Integrated Valuation of Ecosystem Services and Trade-offs(In VEST) model was employed to analyse the spatial changes in ecological space carbon storage in each scenario from 2020 to 2060. Then, this study used a Geographically Weighted Regression(GWR) model to determine the main driving factors that influence the changes in land carbon sinking capacity. The results of the study can be summarised as follows: firstly, the agricultural and ecological priority scenarios will achieve balanced urban expansion and environmental protection of resources in an ecological space. The urbanized priority scenario will reduce the carbon sinking capacity. Among the simulation scenarios for 2060, carbon storage in the urbanized priority scenario will decrease by 112.26 × 10^(6) t compared with that for 2020 and the average carbon density will decrease by 0.96 kg/m^(2) compared with that for 2020. Carbon storage in the agricultural priority scenario will increase by 84.11 × 10^(6) t, and the average carbon density will decrease by 0.72 kg/m^(2). Carbon storage in the ecological priority scenario will increase by 3.03 × 10^(6) t, and the average carbon density will increase by 0.03 kg/m^(2). Under the premise that the population of the town will increases continuously, the ecological priority development approach may be a wise choice.Secondly, slope, distance to river and elevation are the most important factors that influence the carbon sink pattern of the ecological space in the Beibu Gulf urban agglomeration, followed by GDP, population density, slope direction and distance to traffic infrastructure.At the same time, urban space expansion is the main cause of the changes of this natural factors. Thirdly, the decreasing trend of ecological space is difficult to reverse, so reasonable land use policy to curb the spatial expansion of cities need to be made.
文摘Climate change is currently the biggest environmental challenge facing sustainable development in human society,and it is an inherent requirement for achieving sustainable development by actively addressing climate change.Under the increasingly strict constraints of climate governance,developed countries such as the United States,European Union countries,and Japan have responded and actively formulated low-carbon development goals and policy measures that are in line with their national conditions.These policies mainly involve various fields such as low-carbon technology,energy conservation and emission reduction,and circular development,with clear policy guidance.In this paper,the evolution of policies on marine carbon sink and carbon trading in China is summarized,providing support for better understanding the background of formulating relevant international and domestic policies.
文摘Climate change is currently the biggest environmental challenge facing sustainable development in human society,and an inherent requirement for achieving sustainable development is actively addressing climate change.Under the increasingly strict constraints of climate governance,developed countries such as the United States,European Union countries,and Japan have responded and actively formulated low-carbon development goals and policy measures that are in line with their national conditions.These policies mainly involve various fields such as low-carbon technology,energy conservation and emission reduction,and circular development,with clear policy guidance.In this paper,the evolution of policies on marine carbon sink and carbon trading in developed countries such as the United States and Europe is summarized,providing support for a better understanding of the background of international and domestic policy formulation.
基金Supported by Top-notch Young Talent Project of "Ten Thousand Talents Program"in Yunnan Province (YNWR-QNBJ-2019-067)Yunnan Provincial Philosophy and Social Science Base Project (JD2018YB03)Postgraduate Innovation Fund Project of Yunnan University of Finance and Economics(2022YUFEYC097)
文摘[Objectives]To analyze the relationship between the land use pattern and the carbon sequestration level of the ecosystem vegetation in Kunming City,and to provide a certain reference for optimizing the land ecological use pattern and scientific carbon reduction and sequestration.[Methods]Based on remote sensing data,meteorological data,vegetation data and soil data,the Carnegie-Ames-Stanford Approach(CASA)was adopted to estimate the vegetation net primary productivity(NPP)in Kunming during 2005-2020,and then the vegetation carbon sink was calculated through the plant mortality model.Besides,it established the land use transfer matrix of Kunming City,and analyzed the change characteristics of the carbon sink of ecosystem vegetation in Kunming City under the influence of land use changes.[Results]During 2005-2020,the water area,construction land and unused land area in Kunming increased by 43.52,710.51 and 2.8 km 2,respectively;farmland,woodland and grassland decreased by 269.72,140.20 and 347.03 km 2,respectively;farmland,woodland,grassland,water area,construction land and unused land caused a total of 58212.72 t of vegetation net carbon sink loss in land conversion,accounting for 14.88%,25.23%,11.95%,10.58%,37.09%,and 0.26%,respectively.[Conclusions]This study is expected to help to improve the ecological carbon sequestration capacity of Kunming and promote the sustainable development of land resources.
基金Financial supports for this research was provided by the National Nature Science Foundation of China(Grant 40073026)Ministry of Science and Technology of China(Grant 164)+1 种基金Natural Science Foundation of Guangxi(Grant 9824021)Ministry of Land and Resources of China(Grant 9806)and Bremen University of Germany.
文摘The conversion of CO2 into H+ and is a relatively slow reaction. Hence, its kinetics may be rate determining in carbonate rock dissolution. Carbonic anhydrase (CA), which is widespread in nature, was used to catalyze the CO2 conversion process in dissolution experiments of limestone and dolomite. It was found that the rate of dissolution increases by a factor of about 10 after the addition of CA at a high CO2 partial pressure (Pco2) for limestone and about 3 at low Pco2 for dolomite. This shows that reappraisal is necessary for the importance of chemical weathering (including carbonate rock dissolution and silicate weathering) in the atmospheric CO2 sink and the mysterious missing sink in carbon cycling. It is doubtless that previous studies of weathering underestimated weathering rates due to the ignorance of CA as an activator in weathering, thus the contribution of weathering to the atmospheric CO2 sink is also underestimated. This finding also shows the need to examine the situ distribution and activity of CA in different waters and to investigate the role of CA in weathering.
基金supported by the National Natural Scientific Foundation of China(Grant No.40872213)the projects from the China Geological Survey(Grant Nos. 1212010911062 and S-2010-KP03-07-02)+1 种基金from the Ministry of Land and Resources(Grant No.201211086-05)IGCP 598:Environmental Change and Sustainability Karst Systems
基金supported by the Special Fund for Public Benefit Scientific Research of Ministry of Land and Resources of China(No.201111022)IGCP/SIDA 598the China Geological Survey Projects (No.1212011087122,No.1212011220230)
基金This project was supported fi nancially by the National Key Research and Development Program of China(2016YFA0600803)the National Natural Science Foundation of China(31370461).
文摘Wetlands play an important role in the global carbon cycle, but there are still considerable uncertainties in the estimation of wetland carbon storage and a dispute on whether wetlands are carbon sources or carbon sinks. Xiaoxing’anling are one of several concentrated distribution areas of forested wetland in China, but the carbon storage and carbon sink/source of forested wetlands in this area is unclear. We measured the ecosystem carbon storage (vegetation and soil), annual net carbon sequestration of vegetation and annual carbon emissions of soil heterotrophic respiration of five typical forested wetland types (alder swamp, white birch swamp, larch swamp, larch fen, and larch bog) distributed along a moisture gradient in this area in order to reveal the spatial variations of their carbon storage and quantitatively evaluate their position as carbon sink or source according to the net carbon balance of the ecosystems. The results show that the larch fen had high carbon storage (448.8 t ha^(−1)) (6.8% higher than the larch bog and 10.5–30.1% significantly higher than other three wetlands (P < 0.05), the white birch swamp and larch bog were medium carbon storage ecosystems (406.3 and 420.1 t ha^(−1)) (12.4–21.8% significantly higher than the other two types (P < 0.0 5), while the alder swamp and larch swamp were low in carbon storage (345.0 and 361.5 t ha^(−1), respectively). The carbon pools of the five wetlands were dominated by their soil carbon pools (88.5–94.5%), and the vegetation carbon pool was secondary (5.5–11.5%). At the same time, their ecosystem net carbon balances were positive (0.1–0.6 t ha^(−1) a^(−1)) because the annual net carbon sequestration of vegetation (4.0–4.5 t ha^(−1) a^(−1)) were higher than the annual carbon emissions of soil heterotrophic respiration (CO_(2) and CH_(4)) (3.8–4.4 t ha^(−1) a^(−1)) in four wetlands, (the alder swamp being the exception), so all four were carbon sinks while only the alder swamp was a source of carbon emissions (− 2.1 t ha^(−1) a^(−1)) due to a degraded tree layer. Our results demonstrate that these forested wetlands were generally carbon sinks in the Xiaoxing’anling, and there was obvious spatial variation in carbon storage of ecosystems along the moisture gradient.
基金This study was funded by The Social Science Research Fund of National Forestry and Grassland administration(Grant number:2019131028).
文摘The values of forest carbon stock (CSV) and carbon sink (COV) are important topics in the global carbon cycle. We quantitatively analyzed the factors affecting changes in both for forest ecosystem in 2000−2015. With multiple linear stepwise regression analysis, we obtained the factors that had a significant impact on changes of CSV and COV, and then the impacts of these variables on CSV and COV were used for further quantitative analysis using the vector autoregressive model. Our results indicated that both stand age and afforestation area positively affect CSV and COV;however, the forest enterprise gross output value negatively affects CSV. Stand age has the largest long-term cumulative impact on CSV and COV, reaching 40.4% and 9.8%, respectively. The impact of enterprise gross output value and afforestation area on CSV and COV is the smallest, reaching 4.0% and 0.3%, respectively.
基金the World Climate Recruitment Programme’s (WCRP) Working Group on Coupled Modelling (WGCM)the Global Organization for Earth System Science Portals (GO-ESSP)+2 种基金jointly supported by the National Science Foundation of China (Grant Nos. 41991231, 91937302)the China 111 project (Grant No. B13045)supported by Supercomputing Center of Lanzhou University
文摘The measurement of atmospheric O_(2)concentrations and related oxygen budget have been used to estimate terrestrial and oceanic carbon uptake.However,a discrepancy remains in assessments of O_(2)exchange between ocean and atmosphere(i.e.air-sea O_(2)flux),which is one of the major contributors to uncertainties in the O_(2)-based estimations of the carbon uptake.Here,we explore the variability of air-sea O_(2)flux with the use of outputs from Coupled Model Intercomparison Project phase 6(CMIP6).The simulated air-sea O_(2)flux exhibits an obvious warming-induced upward trend(~1.49 Tmol yr−2)since the mid-1980s,accompanied by a strong decadal variability dominated by oceanic climate modes.We subsequently revise the O_(2)-based carbon uptakes in response to this changing air-sea O_(2)flux.Our results show that,for the 1990−2000 period,the averaged net ocean and land sinks are 2.10±0.43 and 1.14±0.52 GtC yr−1 respectively,overall consistent with estimates derived by the Global Carbon Project(GCP).An enhanced carbon uptake is found in both land and ocean after year 2000,reflecting the modification of carbon cycle under human activities.Results derived from CMIP5 simulations also investigated in the study allow for comparisons from which we can see the vital importance of oxygen dataset on carbon uptake estimations.
基金supported by China national key research and development program (2020YFE0204 700)China aid project of MOST (KY201802009)+1 种基金Science and technology project of Guangxi (Guike AD17129047)International cooperation project of CGS (132852KYSB20170029-01)。
文摘It is recognized that karst processes are actively involved in the current global carbon cycle based on twenty years research,and the carbon sink occurred in karst processes is possibly an important part of“missing sink”in global carbon cycle.In this paper,an overview is given on karst carbon cycle research,and influence factors,formed carbon pools(background carbon sink)and sink increase potentials of current karst carbon cycle are analyzed.Carbonate weathering could contribute to the imbalance item(BIM)and land use change item(ELUC)in the global carbon cycle model,owing to its uptake of both atmospheric CO_(2)(carbon sink effect)and CO_(2) produced by soil respiration(carbon source reduction effect).Karst carbon sink includes inorganic carbon sink resulted from hydrogeochemical process and organic carbon sink generated by aquatic photosynthetic DIC conversion,forming relatively stable river(reservoir)water body or sediment carbon sink.The sizes of both sinks are controlled by terrestrial ecosystems and aquatic ecosystems,respectively.Desertification rehabilitation and carbon sequestration by aquatic plants are two effective ways to increase the carbon sink in karst area.It is estimated that the rate of carbon sink is at least 381000 t CO_(2)/a with vegetation restoration and afforestation in southwest China karst area,while the annual organic carbon sink generated by aquatic photosynthesis is about 84200 t C in the Pearl River Basin.The development of a soil CO_(2) based model for assessment of regional dissolution intensity will help to improve the estimation accuracy of carbon sink increase and potential,thus provide a more clear and efficient karst sink increase scheme and pathway to achieve the goals of“double carbon”.With the deep investigation on karst carbon cycle,mechanism and carbon sink effect,and the improvement of watershed carbon sink measurement methods and regional sink increase evaluation approaches.Karst carbon sink is expected to be included in the list of atmospheric CO_(2) sources/sinks of the global carbon budget in the near future.
基金funded by National Natural Science Foundation of China(41373078)National Major Scientific Research Program(2013CB956702)Key Project of Natural Science Research in Colleges and Universities in Jiangsu Province(Grant No.16KJA180003)
文摘Heavy metal pollution in karst mountainous area of Guizhou has spread due to the long-term exploitation of mineral resources and the improper disposal of environmentally hazardous waste. Heavy metals are characterised by non-degradation, strong toxicity, and constant accumulation, posing a grave threat to karst mountain fragile soil ecosystem. To reduce the harm caused by heavy metal pollution and damage to agricultural products, research was undertaken on the basis of previous work by simulating pot experiments on pak choi cabbage(Brassica rapa chinensis)planted in Cd-contaminated soil: different amounts of organic mineral fertilisers(OMF) compared with chemical fertiliser(CF) were used and by detecting the amount of heavy metal in the mature vegetable, a better fertilisation strategy was developed. The results showed that the Cd content in vegetables grown with CF was 23.70 mg/kg,while that of vegetables grown with OMF and bacterial inoculant was the lowest at 15.13 mg/kg. This suggests that the use of OMF and microbes in karst areas not only promotes plant growth but also hinders plant absorption of heavy metal ions in the soil. In addition, through the collection of pot leachate, the detection of water chemistrycharacteristics, and the calculation of the calcite saturation index, it was found that the OMF method also induces certain carbon sink effects. The results provide a new way in which rationalise the use of OMFs in karst areas to alleviate soil heavy metal pollution and increase soil carbon sequestration.
基金Financial support was provided by the National Natural Science Foundation of China (41106094)the Department of Science and Technology Project (BS2010NY030)
文摘As a consequence of global warming and rising sea levels, the oceans are becoming a matter of concern for more and more people because these changes will impact the growth of living organisms as well as people's living standards. In particular, it is extremely important that the oceans absorb massive amounts of carbon dioxide. This paper takes a pragmatic approach to analyzing the oceans with respect to the causes of discontinuities in oceanic variables of carbon dioxide sinks. We report on an application of chemical, physical and biological methods to analyze the changes of carbon dioxide in oceans. Based on the relationships among the oceans, land, atmosphere and sediment with respect to carbon dioxide, the foundation of carbon dioxide in shell-building and ocean acidification, the changes in carbon dioxide in the oceans and their impact on climate change, and so on, a vital conclusion can be drawn from this study. Specifically, under the condition that the oceans are not disturbed by external forces, the oceans are a large carbon dioxide sink. The result can also be inferred by the formula: C=A-B and G=E+F when the marine ecosystem can keep a natural balance and the amount of carbon dioxide emission is limited within the carrying capacity of the oceans.
文摘This study explored the ecological effects of the transformation of carbon source and carbon sink in wetlands, that were discussed from four aspects: atmosphere, ocean, plants and soil. The results showed that the wetland changed from carbon sink to carbon source, which led to the increase of CO_2 emissions in the atmosphere and the intensification of greenhouse effect, which made the earth face the threat of global warming. At the same time, the content of CO_2 in seawater is increased; the pH value of seawater decreases; the balance of seawater acid-base is destroyed; and the ocean acidification is caused.
基金The project partially supported by National Natural Science Foundation of China (No. 10275069)
文摘An actively water-cooled limiter has been designed for the long pulse operation of an HT-7 device, by adopting an integrated structure-doped graphite and a copper alloy heat sink with a super carbon sheet serving as a compliant layer between them. The behaviors of the integrated structure were evaluated in an electron beam facility under different heat loads and cooling conditions. The surface temperature and bulk temperature distribution were carefully measured by optical pyrometers and thermocouples under a steady state heat flux of 1 to 5 MW/m2 and a water flow rate of 3 m3/h, 4.5 m3/h and 6 m3/h, respectively. It was found that the surface temperature increased rapidly with the heat flux rising, but decreased only slightly with the water flow rate rising. The surface temperature reached approximately 1200℃ at 5 MW/m2 of heat flux and 6 ms/h of water flow. The primary experimental results indicate that the integrated design meets the requirements for the heat expelling capacity of the HT-7 device. A set of numerical simulations was also completed, whose outcome was in good accord with the experimental results.
文摘In recent years,there are research findings of haze formation in various fields of academic circle. It has proved that causes of haze take on diverse characteristics. Thus,from both the natural and human perspective,haze governance should be diverse. Research conclusions on causes of haze formation mainly focus on special geographical structure,and meteorological factors such as relatively stable atmosphere,high rate of calm wind,high relative humidity and temperature of air,and human factors such as industrial pollution,automotive exhaust emissions,aerosol pollution,eutrophication of soil water,and change of city underlying surface. Carbon sink mode is a new channel for haze governance.In carbon sink mode,it is feasible to regulate relative humidity and temperature in air,enhance global wind,and reduce fine particles and microorganisms of air pollution,so as to reduce haze pollution. Besides,China's special potential of carbon sink market makes it possible to govern haze on the base of carbon sink.
基金supported by the National Key Research and Development Program of China(2017YFF0206802).
文摘Remote sensing image data of typical mining areas in the Loess Plateau from 1986 to 2018 were used to analyze the evolution of land use,explore the division of carbon sink functional areas,and propose carbon neutrality paths to provide a reference for the coal industry carbon peak,carbon-neutral action plan.Results show that(1)land use has changed signifcantly in the Pingshuo mining area over the past 30 years.Damaged land in industrial,opencast,stripping,and dumping areas comprises 4482.5 ha of cultivated land,1648.13 ha of grassland,and 963.49 ha of forestland.(2)The carbon sink functional areas of the Pingshuo mining land is divided into invariant,enhancement,low carbon optimization,and carbon emission control areas.The proportion of carbon sinks in the invariant area is decreasing,whereas the proportion in enhancement,low carbon optimization,and carbon emission control areas is gradually increasing.(3)The carbon neutrality of the mining area must be reduced from the entire process of stripping–mining–transport–disposal–reclamation,and carbon emissions and carbon sink accounting must start from the life cycle of coal resources.Therefore,carbon neutrality in mining areas must follow the 5R principles of reduction,reuse,recycling,redevelopment,and restoration,and attention must be paid to the potential of carbon sinks in ecological protection and restoration projects in the future.
