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1.
Managing forests to increase carbon sequestration or reduce carbon emissions and using wood products and bioenergy to store carbon and substitute for other emission-intensive products and fossil fuel energy have been considered effective ways to tackle climate change in many countries and regions. The objective of this study is to examine the climate change mitigation potential of the forest sector by developing and assessing potential mitigation strategies and portfolios with various goals in British Columbia (BC), Canada. From a systems perspective, mitigation potentials of five individual strategies and their combinations were examined with regionally differentiated implementations of changes. We also calculated cost curves for the strategies and explored socio-economic impacts using an input-output model. Our results showed a wide range of mitigation potentials and that both the magnitude and the timing of mitigation varied across strategies. The greatest mitigation potential was achieved by improving the harvest utilization, shifting the commodity mix to longer-lived wood products, and using harvest residues for bioenergy. The highest cumulative mitigation of 421 MtCO2e for BC was estimated when employing the strategy portfolio that maximized domestic mitigation during 2017–2050, and this would contribute 35% of BC’s greenhouse gas emission reduction target by 2050 at less than $100/tCO2e and provide additional socio-economic benefits. This case study demonstrated the application of an integrated systems approach that tracks carbon stock changes and emissions in forest ecosystems, harvested wood products (HWPs), and the avoidance of emissions through the use of HWPs and is therefore applicable to other countries and regions.  相似文献   

2.
The use of wood products is often promoted as a climate change mitigation option to reduce atmospheric carbon dioxide concentrations. In previous literature, we identified longevity and recycling rate as two determining factors that influence the carbon stock in wood products, but no studies have predicted the effect of improved wood use on carbon storage over time. In this study, we aimed at evaluating changes in the lifespan and the recycling rate as two options for enhancing carbon stock in wood products for different time horizons. We first explored the behaviour over time of both factors in a theoretical simulation, and then calculated their effect for the European wood sector of the future. The theoretical simulation shows that the carbon stock in wood products increases linearly when increasing the average lifespan of wood products and exponentially when improving the recycling rate. The emissions savings under the current use of wood products in Europe in 2030 were estimated at 57.65 Mt carbon dioxide (CO2) per year. This amount could be increased 5 Mt CO2 if average lifespan increased 19.54 % or if recycling rate increased 20.92 % in 2017. However, the combination of both strategies could increase the emissions saving almost 5 Mt CO2 more by 2030. Incrementing recycling rate of paper and paperboard is the best short-term strategy (2030) to reduce emissions, but elongating average lifespan of wood-based panels is a better strategy for longer term periods (2046).  相似文献   

3.
森林及其产品的固碳功能对减缓气候变化具有重要作用。木质林产品(下简称HWP)的碳储存是全球气候变化的重要议题,研究HWP碳储量并对其进行功能管理,对我国政府提高温室气体减排潜力并参与气候谈判、提交国家温室气体排放清单具有重要的现实意义。论文依据政府间气候变化专门委员会(IPCC)建议的HWP碳量核算模型,研究了1961—2011年中国HWP的固碳功能,继而比较分析了中国HWP碳储量的减排潜力。研究表明:从总量看,储量变化法、大气流动法基础上核算的中国2011 年度碳储量值分别为6.76×108 t 碳和2.58×108 t 碳;从年增长量看,储量变化法、大气流动法基础核算的中国HWP碳储量增长平均值为1 063×104 t 碳和262×104 t 碳。基于中国是世界HWP进口大国,储量变化法的选择应用将对我国有利。HWP碳储量减排贡献的研究发现:中国HWP碳储量为森林立木总量的4.75%~8.42%,平均约为6%;对比中国能源消费的年碳排放量值,中国HWP的年碳储量可以减排约1.6%,中国HWP具有显著的碳汇功能及进一步提升的减排潜力。  相似文献   

4.
Waste management is a significant source of methane (CH4) emissions. CH4 is second to carbon dioxide (CO2) the most important anthropogenic greenhouse gas. In this article the methodology and results from a study on the reduction potential of alternative waste treatment strategies in mitigating the greenhouse impact are presented. The objective is to provide information to decision makers so that the greenhouse issue can be included in the decision making on waste management strategies. The potential cost-effectiveness of reducing the greenhouse impact of alternative waste treatment strategies in three communities of different size in Finland is assessed. The estimation of the greenhouse impact includes estimates of the greenhouse gas (GHG) emissions, the amount of carbon (C) stored at landfills (Csink) and the emission savings that can be achieved by using waste for energy production (assumed decrease in the use of fossil fuels). Landfill gas recovery with energy production was found to be the most-efficient way in reducing the greenhouse impact from large landfills. Burning of all the waste or the combustible fraction in municipal solid waste (MSW) was also an efficient method to reduce greenhouse gas emissions, especially if the energy produced can reduce the burning of fossil fuels. Emissions from transportation of waste are small compared with the emissions from landfills. Even if the transportion mileage is doubled due to increasing separation and recycling the greenhouse impact of transportation would be only 3–4 percent of the impact of landfilling the waste.  相似文献   

5.
The First-Order decay method for carbon stocks is derived from first principles, and applications in the context of national greenhouse gas inventories are discussed. For methane emissions from landfills a method is developed that in principle is more accurate than the method currently recommended by the IPCC, and systematic errors are estimated numerically. The First-Order decay method is further applied to derive the permanent part of the carbon pool of harvested wood products.  相似文献   

6.
人类活动引起的大气温室气体浓度增加是气候变暖的主要原因,全球变暖已经成为了当今人类社会所面临的严峻挑战,应对气候变暖的关键是减少温室气体排放和增加生态系统碳汇,由于生物炭特有的理化和生物学特性,将其施入土壤被认为是一种有前景的减排增汇措施.因此进行生物炭对土壤温室气体排放的影响研究对于减缓温室效应和实现“碳中和”具有重要意义.通过综述生物炭对土壤温室气体排放影响的长短期效应及其影响机制,发现生物炭添加对土壤温室气体排放的影响因生物炭原料类型、热解温度、添加量、土壤和植被类型的不同而不同.此外,因老化时间、老化方式和培养方法的不同,老化生物炭对土壤温室气体的减排效应可能增强或减弱甚至消失.同时,在总结现有研究不足的基础上,对未来生物炭影响土壤温室气体排放研究的方向和重点进行了分析和展望,提出了今后应加强CO2、 N2O和CH4排放影响的同步研究、减排与固碳效应的同步研究、不同老化方式生物炭和不同培养方法的联合研究和利用13C和15N示踪技术从过程层次上揭示影响机制.  相似文献   

7.
Preventing dangerous climate change requires actions on several sectors. Mitigation strategies have focused primarily on energy, because fossil fuels are the main source of global anthropogenic greenhouse gas emissions. Another important sector recently gaining more attention is the forest sector. Deforestation is responsible for approximately one fifth of the global emissions, while growing forests sequester and store significant amounts of carbon. Because energy and forest sectors and climate change are highly interlinked, their interactions need to be analysed in an integrated framework in order to better understand the consequences of different actions and policies, and find the most effective means to reduce emissions. This paper presents a model, which integrates energy use, forests and greenhouse gas emissions and describes the most important linkages between them. The model is applied for the case of Finland, where integrated analyses are of particular importance due to the abundant forest resources, major forest carbon sink and strong linkage with the energy sector. However, the results and their implications are discussed in a broader perspective. The results demonstrate how full integration of all net emissions into climate policy could increase the economic efficiency of climate change mitigation. Our numerical scenarios showed that enhancing forest carbon sinks would be a more cost-efficient mitigation strategy than using forests for bioenergy production, which would imply a lower sink. However, as forest carbon stock projections involve large uncertainties, their full integration to emission targets can introduce new and notable risks for mitigation strategies.  相似文献   

8.
With an evolving political environment of commitments to limit emissions of greenhouse gases, and of markets to trade in emissions permits, there is growing scientific, political, and economic need to accurately evaluate carbon (C) stocks and flows—especially those related to human activities. One component of the global carbon cycle that has been contentious is the stock of carbon that is physically held in harvested wood products. The carbon stored in wood products has been sometimes overlooked, but the amount of carbon contained in wood products is not trivial, it is increasing with time, and it is significant to some Parties. This paper is concerned with accurate treatment of harvested wood products in inventories of CO2 emissions to the atmosphere. The methodologies outlined demonstrate a flexible way to expand current methods beyond the assumption of a simple, first-order decay to include the use of more accurate and detailed data while retaining the simplicity of simple formulas. The paper demonstrates that a more accurate representation of decay time can have significant economic implications in a system where emissions are taxed or emissions permits are traded. The method can be easily applied using only data on annual production of wood products and two parameters to characterize their expected lifetime. These methods are not specific to wood products but can be applied to long-lived, carbon-containing products from sources other than wood, e.g. long-lived petrochemical products. A single unifying approach that is both simple and flexible has the potential to be both more accurate in its results, more efficient in its implementation, and economically important to some Parties.  相似文献   

9.
There are worldwide approximately 4.3 million coffee (Coffea arabica) producing smallholders generating a large share of tropical developing countries’ gross domestic product, notably in Central America. Their livelihoods and coffee production are facing major challenges due to projected climate change, requiring adaptation decisions that may range from changes in management practices to changes in crops or migration. Since management practices such as shade use and reforestation influence both climate vulnerability and carbon stocks in coffee, there may be synergies between climate change adaptation and mitigation that could make it advantageous to jointly pursue both objectives. In some cases, carbon accounting for mitigation actions might even be used to incentivize and subsidize adaptation actions. To assess potential synergies between climate change mitigation and adaptation in smallholder coffee production systems, we quantified (i) the potential of changes in coffee production and processing practices as well as other livelihood activities to reduce net greenhouse gas emissions, (ii) coffee farmers’ climate change vulnerability and need for adaptation, including the possibility of carbon markets subsidizing adaptation. We worked with smallholder organic coffee farmers in Northern Nicaragua, using workshops, interviews, farm visits and the Cool Farm Tool software to calculate greenhouse gas balances of coffee farms. From the 12 activities found to be relevant for adaptation, two showed strong and five showed modest synergies with mitigation. Afforestation of degraded areas with coffee agroforestry systems and boundary tree plantings resulted in the highest synergies between adaptation and mitigation. Financing possibilities for joint adaptation-mitigation activities could arise through carbon offsetting, carbon insetting, and carbon footprint reductions. Non-monetary benefits such as technical assistance and capacity building could be effective in promoting such synergies at low transaction costs.  相似文献   

10.
One of the major concerns with the post-2012 global climate regime is to reach consensus on how to finance actions needed in fast-growing developing economies for significant greenhouses gases emissions mitigation. International financial and technology transfer are bound to bridge the gap under well-designed institutional framework to facilitate the transition to low(er) carbon development trajectories in developing countries. So far, cities, which contribute nearly 80% of global emissions, have not yet been recognised as a legitimate entity to implement different greenhouse gas mitigation policies and measures with relevant technical and financial abilities. Here we discuss the scope and scale of different climate-relevant financial mechanisms and describe their comparative advantages and weakness in financing climate resilient urban infrastructures (buildings and transport in particular). We show the limitations of current instruments available in scaling up necessary financial flows into developing cities to achieve the long term climate stabilisation targets. Lastly, the paper examines the feasibility of factoring the sector-wise and Nationally Appropriate Mitigation Actions (NAMA) mechanisms into local authorities’ long-term mitigation strategy by raising necessary funds to facilitate shifting the business as usual trajectories in developing cities in the next decades.  相似文献   

11.
This paper employs a review of the technical literature to estimate the potential decrease in greenhouse gas (GHG) emissions that could be achieved by increasing the application of gas engines in China in three sectors: urban public transport vehicle; shipping; and thermal power plants. China’s gas engine development strategies and three types of gas resource are discussed in the study, which indicates that gas engines could decrease GHG emissions by 520 megatonnes (Mt) of carbon dioxide equivalent (CO2e) by 2020. This would account for 9.7 % of the government’s target for decreasing GHG emissions and is dominated by methane recovery from the use of coal mine gas (CMG) and landfill gas (LFG) for power generation. In the public urban transport vehicle and shipping sectors the low price of natural gas and the increasing demand for the control of harmful emissions could spur the rapid uptake of gas engine vehicles. However, the development of CMG- and LFG-fuelled power plants has been limited by the unwillingness of local enterprises to invest in high-performance gas engine generators and the associated infrastructure. Therefore, further compulsory policies that promote CMG use and LFG recovery should be implemented. Moreover, strict regulations on limiting methane leakage during the production and distribution of gas fuels are urgently needed in China to prevent leakage causing GHG emissions and largely negating the climate benefits of fuel substitution. Strategies for increasing the application of gas engines, promoting gas resources and recovering methane in China are instrumental in global GHG mitigation strategies.  相似文献   

12.
我国典型露地蔬菜生产中的温室气体排放   总被引:3,自引:0,他引:3  
张芬  程泰鸿  陈新平  王孝忠 《环境科学》2020,41(7):3410-3417
基于国家农业统计数据,以露地番茄、黄瓜、大白菜和萝卜为研究对象,应用生命周期评价(life cycle assessment,LCA)方法,定量化我国4种典型露地蔬菜生产中的净温室气体排放(net greenhouse gas emission,NGHGE),并比较蔬菜种类间、省域间净温室气体排放差异和分析减排措施.结果表明:我国典型露地蔬菜生产系统温室气体排放量远高于其带来的碳固定量,是净温室气体排放系统,生产单位面积露地番茄、黄瓜、大白菜和萝卜净温室气体排放(以CO_2-eq计)分别为4 149、 3 718、 3 780和2 427 kg·hm~(-2),不同种类露地蔬菜净温室气体排放差异大;我国典型露地蔬菜净温室气体排放空间差异大,其中,海南、云南、陕西和山东等省份番茄、黄瓜、大白菜和萝卜净温室气体排放高;肥料生产运输和施用是露地蔬菜温室气体排放的主要贡献因子,贡献率为86.8%~90.8%,因此改善肥料生产工艺降低肥料生产运输过程中的温室气体排放和根据露地蔬菜种类及种植地区优化肥料施用量是实现我国露地蔬菜可持续发展的重要措施.  相似文献   

13.
In its Article 2, the U.N. Framework Convention on Climate Change policymakers gave themselves a long-term dynamic mandate under uncertainty. Taking the example of forestry activities in developing countries, the present article discusses whether land-based climate change mitigation measures in the context of compensation mechanisms for human-induced greenhouse gas emissions are covered under the UNFCCC's ultimate objective. Both the problem of climate change and human intervention act over long, yet finite timeframes. The article argues for taking a dynamic 100-year timeframe as reference for present-day activities. It concludes that increasing biotic carbon storage is legitimate for measures that contribute to biodiversity conservation, as long as it does not serve as a pretext for neglecting technological change. Among all forestry options, the list of priorities should be avoiding deforestation and devegetation, sustainable forest management, and afforestation. The problem of saturation can be encountered by the combination of forestry with the increased use of wood products and bioenergy. Concluding, the article gathers criteria for forest climate activities in the post-2012 regime. JEL Classification: Q23, Q54; Q57; Q58  相似文献   

14.
Full accounting of the greenhouse gas budget in the forestry of China   总被引:1,自引:0,他引:1  
Forest management to increase carbon (C) sinks and reduce C emissions and forest resource utilization to store C and substitute for fossil fuel have been identified as attractive mitigation strategies. However, the greenhouse gas (GHG) budget of carbon pools and sinks in China are not fully understood, and the forestry net C sink must be determined. The objective of this study was to analyze potential forest management mitigation strategies by evaluating the GHG emissions from forest management and resource utilization and clarify the forestry net C sink, and its driving factors in China via constructing C accounting and net mitigation of forestry methodology. The results indicated that the GHG emissions under forest management and resource utilization were 17.7 Tg Ce/year and offset 8.5% of biomass and products C sink and GHG mitigation from substitution effects from 2000 to 2014, resulting in a net C sink of 189.8 Tg Ce/year. Forest resource utilization contributed the most to the national forestry GHG emissions, whereas the main driving factor underlying regional GHG emissions varied. Afforestation dominated the GHG emissions in the southwest and northwest, whereas resource utilization contributed the most to GHG emissions in the north, northeast, east, and south. Furthermore, decreased wood production, improved product use efficiency, and forests developed for bioenergy represented important mitigation strategies and should be targeted implementation in different regions. Our study provided a forestry C accounting in China and indicated that simulations of these activities could provide novel insights for mitigation strategies and have implications for forest management in other countries.  相似文献   

15.
This article analyses the impact of waste recovery on climate change mitigation on a regional scale. We focus on the EU End of Waste (EoW) policy, which aims at reducing negative impacts on the environment through the minimization of generated waste. At the same time, the EU climate objectives set challenging goals for the industry to lower greenhouse gas emissions. We argue that the goals of these two policies are conflicting: under certain circumstances, the EoW will lead into increased greenhouse gas emissions because of a number of negative feedback effects that function on multiple spatial and temporal scales.To assess the effects of waste recovery on greenhouse gas emissions, we carry out a consequential life-cycle inventory on a proposed industrial ecosystem around the Gulf of Bothnia between Finland and Sweden. The system recovers currently unutilized steelmaking dust and slag from four steel mills in Finland and Sweden and converts them into iron and zinc raw materials in a novel rotary hearth furnace. The recovered iron is led back into the blast furnace of one of the steel mills and zinc is treated in an existing zinc plant. In the European scale, the model system is significant in size, serving thus as a model for integrated EoW and carbon footprint assessments in other similar cases within the EU.The analysis reveals the relative greenhouse gas emissions from raw material extraction and production, heat and power generation, transport and the production process itself, in comparison to the present system with limited material recovery. To test the model viability, we conduct a sensitivity analysis with respect to increasing energy and production capacity. Our analysis shows that from the point of view of a single operator, material recovery may bring noteworthy reductions in greenhouse gas emissions. If the scale of the assessment is expanded beyond the confines of a single plant, however, we find limited potential for reducing greenhouse gas emissions through further recovery of steelmaking residues. In conclusion, we provide policy recommendations with which the EoW paradigm can provide better support for climate change mitigation on a regional scale.  相似文献   

16.
While bioenergy plays a key role in strategies for increasing renewable energy deployment, studies assessing greenhouse gas (GHG) emissions from forest bioenergy systems have identified a potential trade-off of the system with forest carbon stocks. Of particular importance to national GHG inventories is how trade-offs between forest carbon stocks and bioenergy production are accounted for within the Agriculture, Forestry and Other Land Use (AFOLU) sector under current and future international climate change mitigation agreements. Through a case study of electricity produced using wood pellets from harvested forest stands in Ontario, Canada, this study assesses the implications of forest carbon accounting approaches on net emissions attributable to pellets produced for domestic use or export. Particular emphasis is placed on the forest management reference level (FMRL) method, as it will be employed by most Annex I nations in the next Kyoto Protocol Commitment Period. While bioenergy production is found to reduce forest carbon sequestration, under the FMRL approach this trade-off may not be accounted for and thus not incur an accountable AFOLU-related emission, provided that total forest harvest remains at or below that defined under the FMRL baseline. In contrast, accounting for forest carbon trade-offs associated with harvest for bioenergy results in an increase in net GHG emissions (AFOLU and life cycle emissions) lasting 37 or 90 years (if displacing coal or natural gas combined cycle generation, respectively). AFOLU emissions calculated using the Gross-Net approach are dominated by legacy effects of past management and natural disturbance, indicating near-term net forest carbon increase but longer-term reduction in forest carbon stocks. Export of wood pellets to EU markets does not greatly affect the total life cycle GHG emissions of wood pellets. However, pellet exporting countries risk creating a considerable GHG emissions burden, as they are responsible for AFOLU and bioenergy production emissions but do not receive credit for pellets displacing fossil fuel-related GHG emissions. Countries producing bioenergy from forest biomass, whether for domestic use or for export, should carefully consider potential implications of alternate forest carbon accounting methods to ensure that potential bioenergy pathways can contribute to GHG emissions reduction targets.  相似文献   

17.
Various utility companies are considering or already initiated the import of biomass from abroad for electricity generation, especially via co-firing in coal-fired power plants. This results in international logistic biomass supply chains, which raise questions on the environmental performance of such chains. In this study, a life cycle inventory has been performed on two existing biomass import chains to evaluate the greenhouse gas balance of biomass import for co-firing. We considered production, transport and co-firing of wood pellets from Canada and palm kernel shells from Malaysia in a 600 MW e coal-fired power plant in the Netherlands. Those chains are compared with various reference systems for energy production and the alternative use of biomass. Primary energy savings of these import and co-firing chains are between 70% and 100% of the biomass energy content. Net avoided greenhouse gas emissions are in the range of 340–2100 g/kWh. In the most optimistic scenario, pellet co-firing avoids methane emissions that would have occurred if the pellets were decomposed at landfills when not applied for energy production. In the most pessimistic scenario, palm kernel shell co-firing competes with the application as resource for animal feed production, which requires production and transport of an alternative resource. As the energy reference systems of the importing and exporting country and the alternative application of biomass have a significant impact on the net avoided greenhouse gas emissions, these factors should be considered explicitly when studying biomass trade for energy purposes.  相似文献   

18.
Carbon dioxide capture and permanent storage (CCS) is one of the most frequently discussed technologies with the potential to mitigate climate change. The natural target for CCS has been the carbon dioxide (CO2) emissions from fossil energy sources. However, CCS has also been suggested in combination with biomass during recent years. Given that the impact on the earth's radiative balance is the same whether CO2 emissions of a fossil or a biomass origin are captured and stored away from the atmosphere, we argue that an equal reward should be given for the CCS, independent of the origin of the CO2. The guidelines that provide assistance for the national greenhouse gas (GHG) accounting under the Kyoto Protocol have not considered CCS from biomass (biotic CCS) and it appears that it is not possible to receive emission credits for biotic CCS under the first commitment period of the Kyoto Protocol, i.e., 2008–2012. We argue that it would be unwise to exclude this GHG mitigation alternative from the competition with other GHG mitigation options. We also propose a feasible approach as to how emission credits for biotic CCS could be included within a future accounting framework.  相似文献   

19.
If hydrogen (H2) is to significantly reduce greenhouse gas emissions and oil use, it needs to displace conventional transport fuels and be produced in ways that do not generate significant greenhouse gas emissions. This paper analyses alternative ways H2 can be produced, transported and used to achieve these goals. Several H2 scenarios are developed and compared to each other. In addition, other technology options to achieve these goals are analyzed. A full fuel cycle analysis is used to compare the energy use and carbon (C) emissions of different fuel and vehicle strategies. Fuel and vehicle costs are presented as well as cost-effectiveness estimates. Lowest hydrogen fuel costs are achieved using fossil fuels with carbon capture and storage. The fuel supply cost for a H2 fuel cell car would be close to those for an advanced gasoline car, once a large-scale supply system has been established. Biomass, wind, nuclear and solar sources are estimated to be considerably more expensive. However fuel cells cost much more than combustion engines. When vehicle costs are considered, climate policy incentives are probably insufficient to achieve a switch to H2. The carbon dioxide (CO2) mitigation cost would amount to several hundred US$ per ton of CO2. Energy security goals and the eventual need to stabilize greenhouse gas concentrations could be sufficient. Nonetheless, substantial development of related technologies, such as C capture and storage will be needed. Significant H2 use will also require substantial market intervention during a transition period when there are too few vehicles to motivate widely available H2 refueling.
Dolf GielenEmail:
  相似文献   

20.
The roles of forest management and the use of timber for energy in the global carbon cycle are discussed. Recent studies assert that past forest management has been accelerating climate change, for example in Europe. In addition, the increasing tendency to burn timber is an international concern. Here, we show a new way of carbon accounting considering the use of timber as a carbon neutral transfer into a pool of products. This approach underlines the robust, positive carbon mitigation effects of sustainable timber harvesting. Applying this new perspective, sustainable timber use can be interpreted not as a removal but a prevention of carbon being converted within the cycle of growth and respiration. Identifying timber use as a prevention rather than a removal leads to the understanding of timber use as being no source of carbon emissions of forests but as a carbon neutral transfer to the product pool. Subsequently, used timber will then contribute to carbon emissions from the pool of forest products in the future. Therefore, timber use contributes to carbon mitigation by providing a substantial delay of emissions. In a second step, the carbon model is applied to results of a previous study in which different timber price scenarios were used to predict timber harvests in Bavarian forests (Germany). Thus, the influence of the economic dimension “timber price” on the ecological dimension carbon sequestration was derived. It also shows that these effects are stable, even if an increasing tendency of burning timber products for producing energy is simulated. Linking an economic optimization to a biophysical model for carbon mitigation shows how the impact of management decisions on the environment can be derived. Overall, a sustainably managed system of forests and forest products contributes to carbon mitigation in a positive, stable way, even if the prices for (energy) wood rise substantially.  相似文献   

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