首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Reducing Emissions from Deforestation and Forest Degradation (REDD+) and enhancing “removals of greenhouse gas emissions by forests” in developing countries through positive incentives is regarded as an essential component of the post-2012 climate regime for stabilizing greenhouse gas emissions and an important way of engaging developing countries in global mitigation efforts. We aimed to evaluate the potential effectiveness of REDD+ by integrating it into a land use option framework. One of our goals was to develop scenarios for evaluating the impacts of land use changes on carbon and environmental processes. In addition, we aimed to quantify the potential economic benefits to society of compensated reductions and to identify hotspots for applying REDD+. Three land use change scenarios were examined: (I) business as usual (BAU), (II) economic development, and (III) REDD+. A case study in Indonesia was examined using these land use scenarios and policy interventions, evaluating their effects on carbon emissions, socioeconomics, and environmental features of a spatial system using land use models. Significant emissions and water erosion reductions were predicted to be achieved under the REDD+ scenario, due to reduced deforestation of <6% over the next decade; >0.14 Mt CO2e reduction was predicted relative to the BAU scenario. Furthermore, the spatial land use model indicated that REDD+ payments of forest carbon credits in the compliance market would play a key role in compensating rural communities and plantation companies for their opportunity cost in ending deforestation. This study provides an example of integrating land use modeling with a scenario analysis framework to evaluate plausible future forecasts and to evaluate the potential impacts of REDD+.  相似文献   

2.
《Water Policy》2001,3(4):321-340
Australia's annual water use of 22,000 Gl is dissected using input–output techniques, showing that 30% of Australia's water requirement was devoted to domestic food production and a further 30% to exports, compared with 7% required for direct consumption by households. There is a net annual trade deficit in embodied water of approximately 4000 Gl. A strong relationship exists between water requirement and expenditure. If by 2050 Australia's population grows to 25 million people and per-capita expenditure doubles, the annual water requirement may more than double to 50,000 Gl, equivalent to half the nation's water flows. While this increase may be improbable it gives the challenge that the water required to deliver a unit of output across the whole economy may have to reduce by a factor of two, if population growth and economic growth are to meet policy expectations.  相似文献   

3.
From the perspective of global economic general equilibrium, this study developed a new climate change IAM named CIECIA. The economic core of this IAM is a multi-country-sector general equilibrium model. The endogenous technology progress mode is introduced into CIECIA. Based on this model, three assessment principles of the global cooperating abatement scheme are proposed, including effectiveness, feasibility, and fairness. This study simulated and analyzed six types of primary global cooperating abatement schemes. The simulated results indicate that all of the selected schemes can satisfy the climate mitigation targets by 2100. Thus, they are all effective schemes. However, the schemes have quite different feasibilities and fairness. The Stern Scheme benefits the developed countries, but is unfair to the developing countries. The Nordhaus Scheme promotes the developments of the developing countries. However, it leads to negative impacts on the interests of the developed countries. The principle of convergence on accumulated carbon emissions per capita and the principle of convergence on carbon emissions per capita benefit the economic developments of the middle and low developing countries most. However, these two types of schemes cause tremendous losses to the main economic entities in the world including China. The Pareto Improvement Scheme, which was developed from the Global Economic Growth Scheme, balances the fairness and feasibility in the carbon abatement process and realizes the Pareto improvement of accumulated utilities in all the participating countries. Thus, the Pareto Improvement Scheme is the most reasonable global cooperating carbon abatement scheme.  相似文献   

4.
Soil erosion in New Zealand exports much sediment and particulate organic carbon (POC) to the sea. The influence of this carbon export on carbon transfers between soils and the atmosphere has been largely unknown. Erosion models are used to estimate the net carbon transfer between soils and atmosphere due to soil erosion for New Zealand. The models are used to estimate the spatial distribution of erosion, which is combined with a digital map of soil organic carbon content to produce the spatial distribution of carbon erosion. The sequestration of atmospheric CO2 by regenerating soils is estimated by combining carbon recovery data with the age distribution of soils since erosion occurrence. The North Island of New Zealand is estimated to export 1·9 (with uncertainty of ?0·5 and +1·0) million tonnes of POC per year to the sea and to sequester 1·25 (?0·3 /+0·6) million tonnes of carbon per year from the atmosphere through regenerating soils. The South Island of New Zealand is estimated to export 2·9 (?0·7/+1·5) million tonnes of POC per year and to sequester approximately the same amount. Assuming exported carbon is buried at sea with an efficiency of 80% gives New Zealand a net carbon sink of 3·1 (?2·0/+2·5) million tonnes per year; which is equivalent to 45% of New Zealand's fossil fuel carbon emissions in 1990. The net sink primarily results from a conveyor belt transfer of carbon from the atmosphere to soils regenerating from erosion to the sea floor where carbon is permanently buried. The net sink due to soil erosion can be further increased by reforestation of those terrains where erosion is excessive and there is no carbon recovery in the soils. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

5.
Boreal mire landscapes are rich in soil carbon and significantly contribute to the carbon input of aquatic ecosystems. They are composed of different mesoscale ecohydrological subunits, whose individual contributions to the water and carbon export of mire catchments are not well understood. The spring snowmelt period is the major hydrological event in the annual water cycle of the boreal regions and strongly influences the carbon flux between the terrestrial and aquatic systems. The aim of this study was (1) to provide a conceptual understanding of the spatial and temporal dynamics of the surface water chemistry along a swamp forest‐fen‐bog gradient during the snowmelt period, (2) to quantify the exported dissolved organic carbon (DOC) content in the runoff and (3) to identify the ecohydrological landscape unit that contributes most to DOC export during the snowmelt period in a heterogeneous mire complex in Northwest Russia. The highest DOC concentrations were detected in the swamp forest, and the lowest concentrations were observed at the treeless bog by the end of the snowmelt period (swamp forest: 37–43 mg l?1, bog: 13–17 mg l?1). During the spring snowmelt period, a significant amount (~1.7 g C m?2) of DOC was transferred by the ~74 mm of runoff from the catchment into the river. Variability in the thawing periods led to differences in the relative contributions of each ecohydrological zone to the carbon export measured at a stream channel draining the studied part of the mire complex. An increased understanding of the variation in DOC concentrations and contributions from the mesoscale ecohydrological subunits to carbon export can help to predict the potential regional loss of DOC based on land cover type under climate change. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

6.
Assessments of the impacts of land use and land cover changes(LUCC) on the terrestrial carbon budget, atmospheric CO2 concentration, and CO2-related climatic change are important to understand the environmental effects of LUCC and provide information about the effects of historical carbon emissions. Using regional land cover reconstructions from historical records, with a bookkeeping model, we estimated the carbon sink changes caused by historical cropland expansion in Northeast China during the past 300 years. The conclusions are as follows:(1) There was a dramatic land reclamation of cropland during the past 300 years in Northeast China. Approximately 26% of the natural land was cultivated, and 38% of the grassland and 20% of the forest and shrubland were converted to cropland.(2) The carbon emission induced by cropland expansion between 1683 and 1980 was 1.06–2.55 Pg C, and the estimation from the moderate scenario was 1.45 Pg C. The carbon emissions of the soil carbon pool was larger than that from the vegetation carbon pool and comprised more than 2/3 of the total carbon emissions.(3) The carbon emissions of the three provinces in Northeast China were different. Heilongjiang Province had the largest carbon emissions, and Jilin Province had the second largest emissions.(4) The primary source of carbon emissions was forest reclamation(taking 60% of the total emissions in the moderate scenario), the secondary source was grassland cultivation(taking 27%), and the tertiary sources were shrubland and wetland reclamation(taking 13%). Examination on the data accuracy revealed that the high-resolution regional land cover data allowed the carbon budget to be evaluated at the county level and improved the precision of the results. The carbon emission estimation in this study was lower than those in previous studies because of the improved land use data quality and various types of land use change considered.  相似文献   

7.
To further understand the roles of carbonate and silicate rocks in regulating the atmosphere/soil CO_2level,the flux of CO_2 consumed by the chemical weathering of silicate and carbonate rocks was determined from the elemental change in soil profiles.Results showed that the chemical weathering of carbonate rocks mainly occurred at the rock-regolith interface,and that the further weathering of the residua soil on the carbonate rocks was similar to that of the granite profile.Chemical weathering of the silicate rocks occurred through the whole profiles.Therefore,CO_2 consumed per volume by the silicate profiles[M_(sr)(CO_2)]and the residues on carbonate rocks[M_(cr)(CO2)]were calculated based on the elemental weathering gradients.CO_2 consumed by carbonate protolith[M_(cp)(CO_2)]was calculated from the elemental change at the rock-regolith interface.The M_(sr)(CO_2) were about tens to thousands orders of magnitude greater than M_(cr)(CO_2).Even so,this demonstrated that the residues on carbonate rocks could be a sink of CO2_ on long-term scales.The M_(cp)(CO_2) was about four times larger than M_(sr)(CO_2),which demonstrated that carbonate rocks played a more important role in regulating the CO_2 level than the silicate rocks did during the pedogenic process of the profiles.  相似文献   

8.
Knowledge of sediment exports from continental areas is essential for estimating denudation rates and biogeochemical cycles. However, the estimation of current sediment fluxes to the sea is often limited by the availability and quality of sediment discharge data. This study aims to quantify the relative contributions of French rivers to the sediment discharge to the ocean. Sediment fluxes were assessed using the French river quality database, which is characterized by a low temporal resolution but long‐term measurement periods. An improved rating curve approach (IRCA) using daily discharge data, which allows the estimation of mean annual sediment loads from infrequent sediment concentration data, was used to calculate sediment fluxes. The resulting mean annual sediment loads show that French rivers export c. 16.21 Mt yr‐1 of sediments to the sea. Among the 88 defined French rivers flowing to the sea, the four largest basins (Loire, Rhone, Garonne and Seine) export 13.2 Mt yr‐1, which corresponds to 81.3% of total exports. No relationship was found between the mass of exported sediment and the size of the drainage basins. This is due to the variety of river basin typologies among these rivers, including lowland rivers in temperate climates, such as the Seine on the one hand and rivers draining mountainous areas in Alpine/Mediterranean areas on the other hand, such as the Rhone. The latter contributes 60% to the total sediment export for France while its drainage area is only 19% of the total area considered. Differences between the river basins considered are also shown by temporal indicators describing the duration of the exports, which may be linked with sediment production processes over drained areas. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

9.
Policies to reduce nitrogen surplus in German agriculture   总被引：1，自引：0，他引：1  
The article focuses on a concept for the creation and evaluation of environmental policy measures. Based on this concept two policy strategies which aim to reduce nitrogen emission from agriculture for spatial resource protection are developed. The strategies are firstly an EU-wide limitation of nitrogen balance surpluses per hectare, and secondly an increase in mineral fertilizer prices plus regional livestock unit limitation. Because of its low costs of administration and control, the authors favour an early introduction of the component ‘regional livestock unit limitation’. If the impacts of this measure do not lead to a sufficient reduction of nitrogen emissions an ‘increase in mineral fertilizer prices’ should be added.  相似文献   

10.
Eutrophication of estuarine and coastal waters has only been recognised as a potential problem since the early 1980s. This problem is being addressed by the European Union through the implementation of recent water quality legislation, which also calls for an economic analysis relating to its implementation. This paper examines the benefits and costs of reduced eutrophication of the Randers Fjord in Denmark, with a primary focus on assessing individual preferences for water quality improvements, using a contingent valuation survey approach. Initial findings of the survey are presented that offer support for funding an action plan to improve the ecological status of the Randers Fjord, as required by the Water Framework Directive. The paper highlights the considerable costs required to abate nutrient emissions into the Fjord, but identifies a need for greater cost evidence at the catchment level.  相似文献   

11.
The changing concepts and challenges that the process industry has to face in relation to environmental protection are discussed. The original requirements on industry to reduce emissions of contaminants through the installation of filters and waste water treatment facilities or through process modification and introduction of ‘clean production’ strategies were mainly based on economic and technical considerations rather than on an effort to avoid environmental impacts. The introduction of concepts such as ‘assimilative capacity of the environment’ and ‘critical load’ provided useful instruments for setting effect-related emission standards, resulting in acceptable environmental protection. However, the actual requirement for ‘sustainability’ has forced industry to focus not only on controlling emissions of contaminants and pollutants, but to take a global environmental approach, including the choice of raw materials and energy sources, recycling and re-utilization of wastes and to take responsibility for the fate of their products, during their whole lifecycle.  相似文献   

12.
Waterborne carbon (C) export from terrestrial ecosystems is a potentially important flux for the net catchment C balance and links the biogeochemical C cycling of terrestrial ecosystems to their downstream aquatic ecosystems. We have monitored hydrology and stream chemistry over 3 years in ten nested catchments (0.6–15.1 km2) with variable peatland cover (0%–22%) and groundwater influence in subarctic Sweden. Total waterborne C export, including dissolved and particulate organic carbon (DOC and POC) and dissolved inorganic carbon (DIC), ranged between 2.8 and 7.3 g m–2 year–1, representing ~10%–30% of catchment net ecosystem exchange of CO2. Several characteristics of catchment waterborne C export were affected by interacting effects of peatland cover and groundwater influence, including magnitude and timing, partitioning into DOC, POC, and DIC and chemical composition of the exported DOC. Waterborne C export was greater during the wetter years, equivalent to an average change in export of ~2 g m–2 year–1 per 100 mm of precipitation. Wetter years led to a greater relative increase in DIC export than DOC export due to an inferred relative shift in dominance from shallow organic flow pathways to groundwater sources. Indices of DOC composition (SUVA254 and a250/a365) indicated that DOC aromaticity and average molecular weight increased with catchment peatland cover and decreased with increased groundwater influence. Our results provide examples on how waterborne C export and DOC composition might be affected by climate change. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

13.
From stable carbon isotope analysis of tree-rings of Chinese pine (Pinus tabulaeformis) from Mt. Helan, China, we found that high-δ13C values were related to high mean temperatures from June to August (T68), and low-δ 13C values corresponded to low T68. From these data, a transfer function has been used to reconstruct summer temperatures (T68) for the Mt. Helan region. The explained variance of reconstruction is 34.9% (F=15.01, p<0.001). The time period containing the highest summer temperatures in northern China (late 1920-1930s) was confirmed by our reconstruction. The data indicate that there is a tele-connection between summer temperatures in Mt. Helan area and sea-surface-temperatures in the tropical Pacific. The extreme low temperature periods around the years of 1920 and 1947 for Mt. Helan region correspond well to the cold climate in the tropical Pacific. Along with other analyses, this suggests that climate variations in the Mt. Helan region are driven not only by local events, but also by the global climate. Significant periodicities appearing in the reconstruction are 2.56 and 2.63 years.  相似文献   

14.
The net ecosystem services value in mainland China   总被引：1，自引：0，他引：1  
Protection of the ecological environment is an effective strategy for maintaining ecosystem health,improving provision of ecosystem services,and increasing human well-being.However,traditional calculations of the value of ecosystem services(VES)provide weak guidance because they ignore the costs of these services,leading to economically inefficient strategies.To understand the difference between VES and the net ecosystem services value(NES,after subtracting costs from VES)and to improve evaluations of ecosystem services,we estimated NES for mainland China(including farmland,grassland,forest,and wetland).NES totaled 10.0×10~3RMB ha~(-1)yr~(-1)in 2014,which is only 35.1%of the corresponding VES.Grassland NES was–0.7×10~3RMB ha~(-1)yr~(-1),in contrast with a positive grassland VES.NES of farmland,grassland,forest,and wetland in2014 totaled 7.2×10~(12)RMB,accounting for 27.0%of China’s GNP.Recent Chinese planning based on VES emphasizes forest conservation and ignores the conservation of other important ecosystems,such as grassland,leading to a continuing loss of China’s natural capital.Due to regional differences in economic conditions,resource endowments,and geographical characteristics,VES and NES differ among regions.To maximize the ecological benefits from conservation,it is necessary to account for these differences by comparing strategies based on NES,thereby choosing projects that maximize both economic and ecological benefits.To maintain the ecological balance,ecological restoration and socioeconomic activities should account for the costs of providing ecosystem services.This is essential to minimize the costs and maximize the benefits of projects.  相似文献   

15.
王婕 《地震工程学报》2020,42(2):558-567
为了解决现有震后重建民用建筑碳排放监测方法未考虑节能减排条件与计算碳排放系数,导致监测结果不准确与监测效率低的问题,提出了一种新的震后恢复重建民用建筑考虑碳排放的研究与监测方法。首先针对碳排放研究的基础进行详细阐述,根据国际碳排放标准开展研究;其次采用排放系数方法,完成建筑碳排放数据采集。具体以建筑使用阶段碳排放的边界条件为基础,确定碳排放边界条件,对震后重建民用建筑全生命周期碳排放进行计算,完成震后建筑碳排放量的实时监测。结果表明：提出的震后建筑碳排放量实时监测方法,能有效的对震后建筑的碳排放量进行实时监测,且具有较高的监测效率。  相似文献   

16.
Heavy use of chemical fertilizer causes increasing soil and environmental crisis, and the use of organic fertilizer increases obvious in recent years. In this study,mineral organic fertilizer(MOF) and compound fertilizer(CF) were applied in amaranth culture to explore the effects of these two kinds of fertilizers on soil quality and the potential function for CO_2 fixation. Some soil parameters were tested, e.g. p H value, organic carbon content, microbial biomass, urease activity, and available potassium content. In addition, some parameters of soil infiltration water were also determined, such as p H and HCO_3~- concentration. Experimental results showed that MOF improved soil quality and amaranth biomass and increased possible soil carbon sink.On the contrary, the utilization of CF worsened soil quality and made the soil acidize. These results suggested that MOF can partially replace CF to improve plant growth, soil quality and possible CO_2 sink.  相似文献   

17.
Diesel engines are being extensively used in the transport sector owing to their excellent fuel efficiency, low emissions of carbon dioxide, unburned hydrocarbons and carbon monoxide. However, high emissions of nitrogen oxides (NOx) and particulate matter (PM) place diesel engines on the down side. It is extremely complex to reduce both emissions at the same time, because of the trade‐off between NOx and PM emissions. Even though the implementation of high pressure injection and common rail system could reduce both NOx and PM emissions together, the cost involved would be high and unaffordable for many engine producers and consumers. In this research work, a new combustion technique termed, porous medium combustion, has been proven to be a proficient technique in reducing both NOx and PM emissions from the direct injection diesel engines. However, the NOx and PM emissions were found to be higher than the conventional engine at low range of part loads.  相似文献   

18.
Headwater forest ecosystems of the western USA generate a large portion of the dissolved organic matter (DOM) transported in streams across North America. Land cover changes that alter forest structure and species composition affect the quantity and composition of DOM transferred to aquatic ecosystems. Clear-cut harvesting affects ~1% of the forest area of North America annually, leaving most western forests in varying stages of regrowth and the total area of old-growth forest is decreasing. The consequences of this widespread management practice on watershed carbon cycling remain unknown. We investigated the role of land cover change, because of clear-cut harvesting, from mixed-species old-growth to lodgepole pine-dominated second-growth forest on the character and reactivity of hillslope DOM exports. We evaluated inputs of DOM from litter leachates and export of DOM collected at the base of trenched hillslopes during a 3-year period (2016–2018) at the Fraser Experimental Forest in north-central Colorado, USA. Dissolved organic carbon and total dissolved nitrogen were higher in lateral subsurface flow draining old- versus second-growth forest. Fluorescence spectroscopy showed that the DOM exported from the old-growth forest was more heterogeneous and aromatic and that proteinaceous, microbially processed DOM components were more prevalent in the second-growth forest. Biological oxygen demand assays revealed much lower microbial metabolism of DOM in litter leachate and subsurface exports from the old-growth forest relative to second growth. Old-growth and second-growth forests are co-mingled in managed ecosystems, and our findings demonstrate that land cover change from a mixture of conifer species to lodgepole pine dominance influences DOM inputs that can increase the reactivity of DOM transferred from terrestrial to aquatic ecosystems.  相似文献   

19.
This study provides the first detailed estimate of riverine organic carbon fluxes in British rivers, as well as highlighting major gaps in organic carbon data in national archives. Existing data on organic carbon and suspended solids concentrations collected between 1989 and 1993, during routine monitoring by the River Purification Boards (RPBs) in Scotland and the National River Authorities (NRAs) in England and Wales, were used with annual mean flows to estimate fluxes of dissolved and particulate organic carbon (DOC and POC) in British rivers. Riverine DOC exports during 1993 varied from 7·7–103·5 kg ha−1 year−1, with a median flux of 31·9 kg ha−1 year−1 in the 85 rivers for which data were available. There was a trend for DOC fluxes to increase from the south and east to the north and west. A predictive model based on mean soil carbon storage in 17 catchments, together with regional precipitation totals, explained 94% of the variation in the riverine DOC exports in 1993. This model was used to predict riverine DOC fluxes in regions where no organic carbon data were available. Calculated and predicted fluxes were combined to produce an estimate for exports of DOC to tidal waters in British rivers during 1993 of 0·68±0·07 Mt. Of this total, rivers in Scotland accounted for 53%, England 38% and Wales 9%. Scottish blanket peats would appear to be the largest single source of DOC exports in British rivers. An additional 0·20 Mt of organic carbon were estimated to have been exported in particulate form in 1993, approximately two–thirds of which was contributed by English rivers. It is suggested that riverine losses of organic carbon have the potential to affect the long-term dynamics of terrestrial organic carbon pools in Britain and that rivers may regulate increases in soil carbon pools brought about by climate change. © 1997 by John Wiley & Sons, Ltd.  相似文献   

20.
In situ observations were combined with 3D modeling to gain understanding of and to quantify the suspended sediment transport in the Gulf of Lions (NW Mediterranean Sea). The outputs of a hydrodynamic–sediment transport coupled model were compared to near-bottom current and suspended sediment concentration measurements collected at the head of seven submarine canyons and at a shallow shelf site, over a 6-month period (November 2003–May 2004). The comparisons provide a reasonable validation of the model that reproduces the observed spatial and time variations. The study period was marked by an unusual occurrence of marine storms and high river inputs. The major water and sediment discharges were supplied by the Rhone, the largest Mediterranean river, during an exceptional flood accompanying a severe marine storm in early December 2003. A second major storm, with moderate flooding, occurred in February 2004. The estimate of river input during the studied period was 5.9 Mt. Our study reveals (i) that most of the particulate matter delivered by the Rhone was entrapped on the prodelta, and (ii) that marine storms played a crucial role on the sediment dispersal on the shelf and the off-shelf export. The marine storms occurring in early December 2003 and late February 2004 resuspended a very large amount of shelf sediment (>8 Mt). Erosion was controlled by waves on the inner shelf and by energetic currents on the outer shelf. Sediment deposition took place in the middle part of the shelf, between 50 and 100 m depth. Resuspended sediments and river-borne particles were transported to the southwestern end of the shelf by a cyclonic circulation induced by these onshore winds and exported towards the Catalan shelf and into the Cap de Creus Canyon which incises the slope close to the shore. Export taking place mostly during marine storms was estimated to reach 9.1 Mt during the study period.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号