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1.
We make an assessment of the impact of projected climate change on forest ecosystems in India. This assessment is based on climate projections of the Regional Climate Model of the Hadley Centre (HadRM3) and the dynamic global vegetation model IBIS for A2 and B2 scenarios. According to the model projections, 39% of forest grids are likely to undergo vegetation type change under the A2 scenario and 34% under the B2 scenario by the end of this century. However, in many forest dominant states such as Chattisgarh, Karnataka and Andhra Pradesh up to 73%, 67% and 62% of forested grids are projected to undergo change. Net Primary Productivity (NPP) is projected to increase by 68.8% and 51.2% under the A2 and B2 scenarios, respectively, and soil organic carbon (SOC) by 37.5% for A2 and 30.2% for B2 scenario. Based on the dynamic global vegetation modeling, we present a forest vulnerability index for India which is based on the observed datasets of forest density, forest biodiversity as well as model predicted vegetation type shift estimates for forested grids. The vulnerability index suggests that upper Himalayas, northern and central parts of Western Ghats and parts of central India are most vulnerable to projected impacts of climate change, while Northeastern forests are more resilient. Thus our study points to the need for developing and implementing adaptation strategies to reduce vulnerability of forests to projected climate change.  相似文献   

2.
Climate change is projected to lead to shift of forest types leading to irreversible damage to forests by rendering several species extinct and potentially affecting the livelihoods of local communities and the economy. Approximately 47% and 42% of tropical dry deciduous grids are projected to undergo shifts under A2 and B2 SRES scenarios respectively, as opposed to less than 16% grids comprising of tropical wet evergreen forests. Similarly, the tropical thorny scrub forest is projected to undergo shifts in majority of forested grids under A2 (more than 80%) as well as B2 scenarios (50% of grids). Thus the forest managers and policymakers need to adapt to the ecological as well as the socio-economic impacts of climate change. This requires formulation of effective forest management policies and practices, incorporating climate concerns into long-term forest policy and management plans. India has formulated a large number of innovative and progressive forest policies but a mechanism to ensure effective implementation of these policies is needed. Additional policies and practices may be needed to address the impacts of climate change. This paper discusses an approach and steps involved in the development of an adaptation framework as well as policies, strategies and practices needed for mainstreaming adaptation to cope with projected climate change. Further, the existing barriers which may affect proactive adaptation planning given the scale, accuracy and uncertainty associated with assessing climate change impacts are presented.  相似文献   

3.
Climate change associated global warming, rise in carbon dioxide concentration and uncertainties in precipitation has profound implications on Indian agriculture. Maize (Zea mays L.), the third most important cereal crop in India, has a major role to play in country’s food security. Thus, it is important to analyze the consequence of climate change on maize productivity in major maize producing regions in India and elucidate potential adaptive strategy to minimize the adverse effects. Calibrated and validated InfoCrop-MAIZE model was used for analyzing the impacts of increase in temperature, carbon dioxide (CO2) and change in rainfall apart from HadCM3 A2a scenario for 2020, 2050 and 2080. The main insights from the analysis are threefold. First, maize yields in monsoon are projected to be adversely affected due to rise in atmospheric temperature; but increased rainfall can partly offset those loses. During winter, maize grain yield is projected to reduced with increase in temperature in two of the regions (Mid Indo-Gangetic Plains or MIGP, and Southern Plateau or SP), but in the Upper Indo-Gangetic Plain (UIGP), where relatively low temperatures prevail during winter, yield increased up to a 2.7°C rise in temperature. Variation in rainfall may not have a major impact on winter yields, as the crop is already well irrigated. Secondly, the spatio-temporal variations in projected changes in temperature and rainfall are likely to lead to differential impacts in the different regions. In particular, monsoon yield is reduced most in SP (up to 35%), winter yield is reduced most in MIGP (up to 55%), while UIGP yields are relatively unaffected. Third, developing new cultivars with growth pattern in changed climate scenarios similar to that of current varieties in present conditions could be an advantageous adaptation strategy for minimizing the vulnerability of maize production in India.  相似文献   

4.
The aim of the study, on which this paper is based, was to provide guidance to consumers to make environmentally responsible choices in their food consumption, to assist food supply chain stakeholders to identify the key areas for environmental improvements, and to provide policy makers with a tool for monitoring the potential impacts on climate change resulting from developments within the food sector. At the macro level, the EIO-LCA model was developed specifically for the Finnish food chain; at the micro level, LCAs were performed on 30 lunch portions. The contribution of the Finnish food chain to climate change was 14%, which comprised 40% CO2 emissions, 25% CH4 emissions, and 34% N2O emissions. The share of impacts from domestic agricultural processes was the highest, at 69%. The impact of a single lunch portion ranged between 0.65 and 3.80 kg of equivalent CO2. According to the EIO-LCA model, the average impact was 7.7 kg CO2 eq/person daily. The consumer phase accounted for between 8 and 47% of the climate change impacts for homemade portions. In ready-to-eat portions industry and retail phases were emphasized, representing 25-38% of climate change impacts. We present an approach to steer the Finnish food sector onto an environmentally sustainable path; practical tools for consumers and farmers will especially need to be developed further.  相似文献   

5.
A dynamic growth model (CO2FIX) was used for estimating the carbon sequestration potential of sal (Shorea Robusta Gaertn. f.), Eucalyptus (Eucalyptus Tereticornis Sm.), poplar (Populus Deltoides Marsh), and teak (Tectona Grandis Linn. f.) forests in India. The results indicate that long-term total carbon storage ranges from 101 to 156 Mg C?ha?1, with the largest carbon stock in the living biomass of long rotation sal forests (82 Mg C?ha?1). The net annual carbon sequestration rates were achieved for fast growing short rotation poplar (8 Mg C?ha?1?yr?1) and Eucalyptus (6 Mg C?ha?1?yr?1) plantations followed by moderate growing teak forests (2 Mg C?ha?1?yr?1) and slow growing long rotation sal forests (1 Mg C?ha?1?yr?1). Due to fast growth rate and adaptability to a range of environments, short rotation plantations, in addition to carbon storage rapidly produce biomass for energy and contribute to reduced greenhouse gas emissions. We also used the model to evaluate the effect of changing rotation length and thinning regime on carbon stocks of forest ecosystem (trees?+?soil) and wood products, respectively for sal and teak forests. The carbon stock in soil and products was less sensitive than carbon stock of trees to the change in rotation length. Extending rotation length from the recommended 120 to 150 years increased the average carbon stock of forest ecosystem (trees?+?soil) by 12%. The net primary productivity was highest (3.7 Mg ha?1?yr?1) when a 60-year rotation length was applied but decreased with increasing rotation length (e.g., 1.7 Mg ha?1?yr?1) at 150 years. Goal of maximum carbon storage and production of more valuable saw logs can be achieved from longer rotation lengths. ‘No thinning’ has the largest biomass, but from an economical perspective, there will be no wood available from thinning operations to replace fossil fuel for bioenergy and to the pulp industry and such patches have high risks of forest fires, insects etc. Extended rotation lengths and reduced thinning intensity could enhance the long-term capacity of forest ecosystems to sequester carbon. While accounting for effects of climate change, a combination of bioenergy and carbon sequestration will be best to mitigation of CO2 emission in the long term.  相似文献   

6.
There is huge knowledge gap in our understanding of many terrestrial carbon cycle processes. In this paper, we investigate the bounds on terrestrial carbon uptake over India that arises solely due to CO 2 -fertilization. For this purpose, we use a terrestrial carbon cycle model and consider two extreme scenarios: unlimited CO2-fertilization is allowed for the terrestrial vegetation with CO2 concentration level at 735 ppm in one case, and CO2-fertilization is capped at year 1975 levels for another simulation. Our simulations show that, under equilibrium conditions, modeled carbon stocks in natural potential vegetation increase by 17 Gt-C with unlimited fertilization for CO2 levels and climate change corresponding to the end of 21st century but they decline by 5.5 Gt-C if fertilization is limited at 1975 levels of CO2 concentration. The carbon stock changes are dominated by forests. The area covered by natural potential forests increases by about 36% in the unlimited fertilization case but decreases by 15% in the fertilization-capped case. Thus, the assumption regarding CO2-fertilization has the potential to alter the sign of terrestrial carbon uptake over India. Our model simulations also imply that the maximum potential terrestrial sequestration over India, under equilibrium conditions and best case scenario of unlimited CO2-fertilization, is only 18% of the 21st century SRES A2 scenarios emissions from India. The limited uptake potential of the natural potential vegetation suggests that reduction of CO2 emissions and afforestation programs should be top priorities.  相似文献   

7.
To prepare agricultural systems for climate change, scientists need to be able to effectively engage with land managers and policy makers to explore potential solutions. An ongoing challenge in engagement is to distil the complexity of climate-change-management-change interactions in agro-ecological systems to identify responses that are most important for adaptation planning. This paper presents an approach for selecting climate change scenarios to provide a focal point for engaging with stakeholders to evaluate adaptation options and communicate assessment outcomes. We illustrate how scenarios selected with the approach can be used by evaluating climate change impacts and an adaptation option for livestock industries in the north-east Australian rangelands. Climate change impacts on forage production, animal liveweight gain and soil loss are found to track projected climate changes in four pasture communities; increasing by up to 50% and declining by up to 110% in response to doubled atmospheric carbon-dioxide (CO2), 4°C warming, and +20% to ?40% changes in mean annual rainfall. The effectiveness of reducing grazing pressure as an adaptation option shows a similar response; resulting in higher forage production (up to 40%), animal liveweight gains (up to 59%) and gross margins (up to 40%), and reduced soil erosion (down by 91%) per hectare relative to the baseline management. The results show that a few key scenarios may be selected to represent the range of global climate model (GCM) projections for use in assessing and communicating impacts and adaptation; simplifying the assessments and allowing limits to the effectiveness of adaptation options to be explored. The approach provides a framework for capturing and communicating trends in climate change impacts and the utility of options, which are required for successful engagement of stakeholders in finding viable adaption responses.  相似文献   

8.
This paper analyzes potential impacts of climate change on biomass carbon (C) density and water-use (actual evapotranspiration, AET) of savannah woodlands in Sudan. Climate change scenarios were developed from five General Circulation Models (GCMs; CGCM2, CSIRO2, ECHam4, HadCM3 and PCM) under two IPCC (Intergovernmental Panel on Climate Change) emission scenarios (A1FI and B1). Baseline (1961-90) climate and climate change scenarios for 2080s for eight map sheet grids (1° latitude x 1.5° longitude) were constructed. Compared to baseline values, mean annual precipitation (MAP) showed both increases (+112 to +221 mm) and decreases (?13 to ?188 mm) but mean annual temperature (MAT) only showed increases (+1.2 to +8.3 °C). Baseline biomass C densities showed an exponential relationship with MAP (y?=?6.798 e 0.0054x, R2?=?0.70). Depending on climate change MAP, biomass C densities increased (+14 to +241 g C m?2) or decreased (?1 to ?148 g?C m?2). However, because of uncertainty in biomass C density estimates, the changes were only significant (P <0.05) for some of the climate change scenarios and for grids with MAP >260 mm. Under A1FI emission scenarios, only HadCM3 did not have a significant effect while under B1 emission scenarios, only CGCM2 and ECHam4 had a significant effect on biomass C density. AET also showed both increases (+100 to +145 mm for vertisols and +82 to +197 mm for arenosols) and decreases (?12 to ?178 mm for vertisols and ?12 to ?132 mm for arenosols). The largest relative changes in AET (up to 31 %) were associated with grids receiving the lowest rainfall. Thus, even if MAP increases across the study region, the increase will have little impact on biomass levels in the driest areas of the region, emphasizing the need for improved management and use of savannah woodlands.  相似文献   

9.
Among the key issues of concern to the Climate Convention is the stabilization of greenhouse gas concentrations and the minimization of impacts to global agriculture, natural ecosystems and economic development. The purpose of this paper is to couple these issues in consistent, integrated scenarios, using the IMAGE 2.0 model as an integrating tool. Scenarios of gradual stabilization of atmospheric CO2 at 350 and 450 ppm are compared to a baseline of no policy action in which CO2 concentration increases to 777 ppm. Under the stabilizaton scenarios substantially smaller areas of wheat and millet, as well as nature reserves, are threatened by climate change, especially in temperate regions. The amount of sea level rise is also reduced under the stabilization scenarios. However, climate continues to change under the stabilization scenarios and therefore some ‘residual’ climate impacts occur. Hence the integrated scenarios indicate that stabilizing greenhouse gas concentrations at or slightly above current levels will lessen impacts as compared to baseline levels, but not eliminate them. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

10.
Switchgrass(Panicum virgatum L.) is a perennial C_4 grass native to North America and successfully adapted to diverse environmental conditions. It offers the potential to reduce soil surface carbon dioxide(CO_2) fluxes and mitigate climate change. However, information on how these CO_2 fluxes respond to changing climate is still lacking. In this study, CO_2 fluxes were monitored continuously from 2011 through 2014 using high frequency measurements from Switchgrass land seeded in 2008 on an experimental site that has been previously used for soybean(Glycine max L.) in South Dakota, USA. DAYCENT, a process-based model, was used to simulate CO_2 fluxes. An improved methodology CPTE[Combining Parameter estimation(PEST) with "Trial and Error" method] was used to calibrate DAYCENT. The calibrated DAYCENT model was used for simulating future CO_2 emissions based on different climate change scenarios. This study showed that:(i) the measured soil CO_2 fluxes from Switchgrass land were higher for 2012 which was a drought year, and these fluxes when simulated using DAYCENT for long-term(2015–2070) provided a pattern of polynomial curve;(ii) the simulated CO_2 fluxes provided different patterns with temperature and precipitation changes in a long-term,(iii) the future CO_2 fluxes from Switchgrass land under different changing climate scenarios were not significantly different, therefore, it can be concluded that Switchgrass grown for longer durations could reduce changes in CO_2 fluxes from soil as a result of temperature and precipitation changes to some extent.  相似文献   

11.
Climate change is projected to impact forest ecosystems, including biodiversity and Net Primary Productivity (NPP). National level carbon forest sector mitigation potential estimates are available for India; however impacts of projected climate change are not included in the mitigation potential estimates. Change in NPP (in gC/m2/yr) is taken to represent the impacts of climate change. Long term impacts of climate change (2085) on the NPP of Indian forests are available; however no such regional estimates are available for short and medium terms. The present study based on GCM climatology scenarios projects the short, medium and long term impacts of climate change on forest ecosystems especially on NPP using BIOME4 vegetation model. We estimate that under A2 scenario by the year 2030 the NPP changes by (−5) to 40% across different agro-ecological zones (AEZ). By 2050 it increases by 15% to 59% and by 2070 it increases by 34 to 84%. However, under B2 scenario it increases only by 3 to 25%, 3.5 to 34% and (−2.5) to 38% respectively, in the same time periods. The cumulative mitigation potential is estimated to increase by up to 21% (by nearly 1 GtC) under A2 scenario between the years 2008 and 2108, whereas, under B2 the mitigation potential increases only by 14% (646 MtC). However, cumulative mitigation potential estimates obtained from IBIS—a dynamic global vegetation model suggest much smaller gains, where mitigation potential increases by only 6% and 5% during the period 2008 to 2108.  相似文献   

12.
Air quality and related health effects are not only affected by policies directly addressed at air pollution but also by other environmental strategies such as climate mitigation. This study addresses how different climate policy pathways indirectly bear upon air pollution in terms of improved human health in Europe. To this end, we put in perspective mitigation costs and monetised health benefits of reducing PM2.5 (particles less than 2.5 μm in diameter) and ozone concentrations.Air quality in Europe and related health impacts were assessed using a comprehensive modelling chain, based on global and regional climate and chemistry-transport models together with a health impact assessment tool. This allows capturing both the impact of climate policy on emissions of air pollutants and the geophysical impact of climate change on air quality.Results are presented for projections at the 2050 horizon, for a set of consistent air pollution and climate policy scenarios, combined with population data from the UN's World Population Prospects, and are expressed in terms of morbidity and mortality impacts of PM2.5 and ozone pollution and their monetised damage equivalent.The analysis shows that enforcement of current European air quality policies would effectively reduce health impacts from PM2.5 in Europe even in the absence of climate policies (life years lost from the exposure to PM2.5 decrease by 78% between 2005 and 2050 in the reference scenario), while impacts for ozone depend on the ambition level of international climate policies. A move towards stringent climate policies on a global scale, in addition to limiting global warming, creates co-benefits in terms of reduced health impacts (68% decrease in life years lost from the exposure to PM2.5 and 85% decrease in premature deaths from ozone in 2050 in the mitigation scenario relative to the reference scenario) and air pollution cost savings (77%) in Europe. These co-benefits are found to offset at least 85% of the additional cost of climate policy in this region.  相似文献   

13.
Rice (Oryza) is a staple food in China, and rice yield is inherently sensitive to climate change. It is of great regional and global importance to understand how and to what degree climate change will impact rice yields and to determine the adaptation options effectiveness for mitigating possible adverse impacts or for taking advantage of beneficial changes. The objectives of this study are to assess the climate change impact, the carbon dioxide (CO2) fertilization effect, and the adaptation strategy effectiveness on rice yields during future periods (2011–2099) under the newly released Representative Concentration Pathway (RCP) 4.5 scenario in the Sichuan Basin, one of the most important rice production areas of China. For this purpose, the Crop Estimation through Resource and Environment Synthesis (CERES)-Rice model was applied to conduct simulation, based on high-quality meteorological, soil and agricultural experimental data. The modeling results indicated a continuing rice reduction in the future periods. Compared to that without incorporating of increased CO2 concentration, a CO2 fertilization effect could mitigate but still not totally offset the negative climate change impacts on rice yields. Three adaptive measures, including advancing planting dates, switching to current high temperature tolerant varieties, and breeding new varieties, could effectively offset the negative climate change impacts with various degrees. Our results will not only contribute to inform regional future agricultural adaptation decisions in the Sichuan Basin but also gain insight into the mechanism of regional rice yield response to global climate change and the effectiveness of widely practiced global thereby assisting with appropriate adaptive strategies.  相似文献   

14.
The effects of a 1.5 °C global change on irrigation costs and carbon emissions in a groundwater-dependent irrigation system were assessed in the northwestern region of Bangladesh and examined at the global scale to determine possible global impacts and propose necessary adaptation measures. Downscaled climate projections were obtained from an ensemble of eight general circulation models (GCMs) for three representative concentration pathways (RCPs), RCP2.6, RCP4.5, and RCP8.5 and were used to generate the 1.5 °C warming scenarios. A water balance model was used to estimate irrigation demand, a support vector machine (SVM) model was used to simulate groundwater levels, an energy-use model was used to estimate carbon emissions from the irrigation pump, and a multiple linear regression (MLR) model was used to simulate the irrigation costs. The results showed that groundwater levels would likely drop by only 0.03 to 0.4 m under a 1.5 °C temperature increase, which would result in an increase in irrigation costs and carbon emissions ranging from 11.14 to 148.4 Bangladesh taka (BDT) and 0.3 to 4% CO2 emissions/ha, respectively, in northwestern Bangladesh. The results indicate that the impacts of climate change on irrigation costs for groundwater-dependent irrigation would be negligible if warming is limited to 1.5 °C; however, increased emissions, up to 4%, from irrigation pumps can have a significant impact on the total emissions from agriculture. This study revealed that similar impacts from irrigation pumps worldwide would result in an increase in carbon emissions by 4.65 to 65.06 thousand tons, based only on emissions from groundwater-dependent rice fields. Restricting groundwater-based irrigation in regions where the groundwater is already vulnerable, improving irrigation efficiency by educating farmers and enhancing pump efficiency by following optimum pumping guidelines can mitigate the impacts of climate change on groundwater resources, increase farmers’ profits, and reduce carbon emissions in regions with groundwater-dependent irrigation.  相似文献   

15.
The Cameroonian agricultural sector, a critical part of the local ecosystem, is potentially vulnerable to climate change raising concerns about food security in the country’s future. Adaptations policies may be able to mitigate some of this vulnerability. This article investigates and addresses the issue of selected adaptation options within the context of Cameroonian food production. A methodology is applied where transient diagnostics of two atmosphere–ocean general circulation models, the NASA/Goddard Institute GISS and the British HadCM3, are coupled to a cropping system simulation model (CropSyst) to simulate current and future (2020, 2080) crop yields for selected key crops (bambara nut, groundnut, maize, sorghum, and soybean) in eight agricultural regions of Cameroon. Our results show that for the future, substantial yield increases are estimated for bambara groundnut, soybean and groundnut, while little or no change or even decreases for maize and sorghum yields, varying according to the climate scenario and the agricultural region investigated. Taking the “no regrets” principle into consideration, we explore the advantages of specific adaptation strategies specifically for three crops viz. maize, sorghum and bambara groundnut, under GISS A2 and B2 marker scenarios only. Changing sowing dates may be ineffective in counteracting adverse climatic effects because of the narrow rainfall band that strictly determines the timing of farm operations in Cameroon. In contrast, the possibility of developing later maturing new cultivars proved to be extremely effective in offsetting adverse impacts, giving the highest increases in productivity under different scenario projections without management changes. For example, under climate change scenario GISS A2 2080, a 14.6% reduction in maize yield was converted to a 32.1% increase; a 39.9% decrease in sorghum yield was converted to a 17.6% increase, and for bambara groundnut (an under-researched and underutilised African legume), yields were almost trebled (37.1% increase above that for sowing date alone (12.9%)) due to increase length of growing period and the positive effects of higher CO2 concentrations. These results may better inform wider studies and development strategies on sustainable agriculture in the area by providing an indication as to the potential direction in shifts in production capabilities. Our approach highlights the benefit of using models as tools to investigate potential climate change impacts, where results can supplement existing knowledge. The results provide useful guidance and motivation to public authorities and development agencies interested in food security issues in Cameroon and elsewhere.  相似文献   

16.
Emissions of air pollutants cause damage to health and crops, but several air pollutants also have an effect on climate through radiative forcing. We investigate efficiency gains achieved by integrating climate impacts of air pollutants into air quality strategies for the EU region. The pollutants included in this study are SO2, NH3, VOC, CO, NOx, black carbon, organic carbon, PM2.5, and CH4. We illustrate the relative importance of climate change effects compared to damage to health and crops, as well as monetary gains of including climate change contributions. The analysis considers marginal abatement costs and compares air quality and climate damage in Euros. We optimize abatement policies with respect to both climate and health impacts, which imply implementing all measures that yield a net benefit. The efficiency gains of the integrated policy are in the order of 2.5 billion Euros, compared to optimal abatement based on health and crop damage only, justifying increased abatement efforts of close to 50%. Climate effect of methane is the single most important factor. If climate change is considered on a 20- instead of a 100-year time-scale, the efficiency gain almost doubles. Our results indicate that air pollution policies should be supplemented with climate damage considerations.  相似文献   

17.
This paper examines the risks associated with forest insect outbreaks in a changing climate from biological and forest management perspectives. Two important Canadian insects were considered: western spruce budworm (WSBW; Choristoneura occidentalis Freeman, Lepidoptera: Tortricidae), and spruce bark beetle (SBB; Dendroctonus rufipennis Kirby, Coleoptera: Curculionidae). This paper integrates projections of tree species suitability, pest outbreak risk, and bio-economic modelling.Several methods of estimating pest outbreak risk were investigated. A simple climate envelope method based on empirically derived climate thresholds indicates substantial changes in the distribution of outbreaks in British Columbia for two climate scenarios and both pests. A “proof of concept” bio-economic model, to inform forest management decisions in a changing climate, considers major stand-level harvest decision factors, such as preservation of old-growth forest, and even harvest flow rates in the presence of changing tree species suitability and outbreak risk. The model was applied to data for the Okanagan Timber Supply Area and also the entire Province of British Columbia.At the provincial level, the model determined little net timber production impact, depending on which of two climate scenarios was considered. Several potentially important factors not considered in this first version of the model are discussed, which indicates that impact may be underestimated by this preliminary study. Despite these factors, negative impacts were projected at the Okanagan Timber Supply Area level for both scenarios.Policy implications are described as well as guidance for future work to determine impacts of climate change on future distribution and abundance of forest resources.  相似文献   

18.
气候变化和土壤侵蚀是当前全球变化研究重点关注的两个自然过程,二者之间的相互作用是地表过程的重要研究内容之一。本文从土壤侵蚀对气候变化的响应、碳循环过程对土壤侵蚀的反馈两个方面综述了气候变化与土壤侵蚀相互作用研究进展。分析认为:理想的地质载体是深刻理解地质历史时期土壤侵蚀对气候变化响应特征的关键;土壤侵蚀预测模型的适用条件和范围以及降雨侵蚀力估算方法缺乏标准化是造成土壤侵蚀量估算结果存在差异的主要因素;侵蚀作用下土壤有机碳矿化的生物学过程与机制是科学评估土壤侵蚀是碳源或碳汇的关键环节。建议未来在以下三个方向开展工作:(1)以湖泊沉积物为地质载体研究历史时期气候变化与土壤侵蚀有着巨大发展和应用潜力,建议利用AMS 14C、137Cs和210Pb等多种定年手段,使用环境指示意义明确的代用指标,建立近千年高分辨率流域气候与侵蚀序列,研究十年至百年尺度气候变化与土壤侵蚀之间的关系;(2)流域版水蚀预报模型(WEPP)可能更适合小流域预测研究,在其实践应用过程中除规范标准小区的坡度和坡长之外,还应通过长期观测和试验确定不同气候区侵蚀性降雨阙值以计算降雨侵蚀力;(3)可以尝试采用定量稳定同位素探针技...  相似文献   

19.
This paper uses the likelihood of flooding along Brahmaputra and Ganges Rivers in India to explore the hypothesis that adaptation and mitigation can be viewed as complements rather than sustitutes. For futures where climate change will produce smooth, monotonic and manageable effects, adopting a mitigation strategy is shown to increase the ability of adaptation to reduce the likelihood of crossing critical threshold of tolerable climate. For futures where climate change will produce variable impacts overtime, though, it is possible that mitigation will make adaptation less productive for some time intervals. In cases of exaggerated climate change, adaptation may fail entirely regardless of how much mitigation is applied. Judging the degree of complementarity is therefore an empirical question because the relative efficacy of adaptation is site specific and path dependent. It follows that delibrations over climate policy should rely more on detailed analyses of how the distributions of possible impacts of climate might change over space and time.
Gary YoheEmail:
  相似文献   

20.
This paper provides an analysis of co-benefits for traditional air pollutants made possible through global climate policies using the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model in the time horizon up to 2050. The impact analysis is based on projections of energy consumption provided by the Prospective Outlook for the Long term Energy System (POLES) model for a scenario without any global greenhouse gas mitigation efforts, and for a 2°C climate policy scenario which assumes internationally coordinated action to mitigate climate change. Outcomes of the analysis are reported globally and for key world regions: the European Union (EU), China, India and the United States. The assessment takes into account current air pollution control legislation in each country. Expenditures on air pollution control under the global climate mitigation regime are reduced in 2050 by 250 billion € when compared to the case without climate measures. Around one third of financial co-benefits estimated world-wide in this study by 2050 occur in China, while an annual cost saving of 35 billion (Euros) € is estimated for the EU if the current air pollution legislation and climate policies are adopted in parallel. Health impacts of air pollution are quantified in terms of loss of life expectancy related to the exposure from anthropogenic emissions of fine particles, as well as in terms of premature mortality due to ground-level ozone. For example in China, current ambient concentrations of particulate matter are responsible for about 40 months-losses in the average life expectancy. In 2050, the climate strategies reduce this indicator by 50 %. Decrease of ozone concentrations estimated for the climate scenario might save nearly 20,000 cases of premature death per year. Similarly significant are reductions of impacts on ecosystems due to acidification and eutrophication.  相似文献   

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