寒旱区草原湖泊沉积物重金属地球化学基线构建——以达里诺尔湖为例

为了科学识别寒旱区典型草原湖泊——达里诺尔湖的沉积物重金属累积状况,在调查表层及柱状沉积物重金属含量的基础上,采用多种统计学方法构建了沉积物重金属地球化学基线,并针对构建结果进行了多方面比较分析.结果表明,Cr、Ni、Cu、Zn、As、Cd、Hg、Pb在表层及柱状沉积物中均呈正态分布或对数正态分布,其中,柱状沉积物中的重金属分布较表层更为集中,且As、Cd、Hg在近表层呈现较明显的增长趋势,表明存在一定的表层富集;使用参考元素法、相对累积频率法和迭代2倍标准差法构建的表层、柱状沉积物重金属基线值之间无显著差异（P<0.05）,综合考虑科学性,适用性,简便性,人为误差性等方面,可优先选取迭代2倍标准差法进行元素基线构建;研究构建的达里诺尔湖沉积物重金属基线值与所在区域的大尺度土壤背景值相比存在差异,且表层与柱状沉积物基线值也存在差异,考虑到达里诺尔湖流域人为干扰极小,使用研究区域的表层沉积物开展基线值构建,可为识别湖泊当前重金属富集状况和生态风险提供更为科学和准确的参考依据.研究结果可为类似的寒旱区草原湖泊沉积物重金属基线值构建提供理论依据.     

Options for baselines of the clean development mechanism

The Kyoto Protocol created the Clean Development Mechanism (CDM) to allow industrial countries to reach part of their greenhouse gas (GHG) emission reduction through projects in developing countries. To calculate the achieved emission reduction a reference scenario has to be developed – the baseline. Despite efforts to develop realistic baselines, a certain degree of uncertainty regarding actual reductions will be inevitable. It is therefore necessary to compare the costs (including transaction costs) of developing a baseline against the informational benefit it can be expected to produce. While project-related baselines are already being applied, the proponents of country-related baselines have still to show the applicability of their approach for the CDM. The possibility of quantifying indirect effects and considering market distortions and subsidies through aggregation in the country-related baselines is weighed up by the manipulability and uncertainty of the assumptions required in such a baseline. Thus project-specific baselines are recommended. In cases of severely distorted markets undergoing liberalization or subsidy phase-out, a country-related baseline can be helpful. Sectoral or programme baselines would be suited to large-scale energy and sequestration projects. Moreover it has to be considered whether emission reductions are generally achieved in the context of relocation or done in the context of global emitting capacity expansion.     

Preserving Environmental Integrity in standardised baselines: The role of additionality and uncertainty

The European Union EU project PROBASE hasexplored a range of possible multi projectstandardised benchmarks as a way ofencouraging projects under Joint Implementation (JI) and the Clean Development Mechanism (CDM)by minimising transaction costs. The aim ofthis paper is to examine the environmentalintegrity of the use of standardisedbaselines and to explore the role ofadditionality. The environmental integritydepends on the uncertainty in emissionreductions, which was estimated bygenerating scenario baselines and comparingthese with the standardised baselines. Thishas allowed a comparison of selected multiproject baselines with the envelope ofuncertainty on the reductions. The projectsincluded a range of electricity supply,heat sector, cogeneration and methane(CH$_{4}$) projects in different countries. Theanalysis showed that the key uncertaintieswere in the technology fuel selection inthe baseline, the continued additionalityof the project emission reductions,uncertainties in some project emissions(e.g. spinning reserve emissions for wind)and data uncertainties. The effect on theestimation of reductions was in the range±12% to ±46% for the electricityprojects and from ±19% to ±57%for the heat and Combined Heat and Power CHP sector projects.Comparison with the envelope of uncertaintyfor the range of projects showed that multiproject electricity sector baselines whichhave been weighted or use high technologyperformance benchmarks (e.g. Organization for Economic Cooperation and Development OECD)can provide conservative estimates buttheir general nature can lead to variationsbetween countries. We would recommend thatthe country-specific context must be takeninto account so that standardised baselinesfor the electricity sector are generated onthe basis of country specificcharacteristics, the project type, andwhether it provides new or existing demand.The conservative scenario produced shouldthen be weighted. Whereas weightings havebeen applied to account for uncertaintiesor to bias towards renewables, we havesuggested a weighting factor of 25% on theelectricity baseline for large projectsbased on an analysis of the effect ofnon-additionality on emission reductionuncertainty. For heat projects, theappropriate benchmark is a technology/fuelbenchmark which is deemed relevant for theheat sector in that (part of the) country.Again we suggest that a weighted sectorbaseline is required to take account of theuncertainties. These recommendations applyto large projects only for a 10-yearcrediting lifetime.     

Forest Management for Greenhouse Gas Benefits: Resolving Monitoring Issues Across Project and National Boundaries

Demand for new environmental services from forests requires improved monitoring of these services at three scales: project-, regional-, and national-level. Most forest management activities are organized at the project scale, while the Framework Convention on Climate Change (FCCC) recognizes the nation as the party to the agreement. Hence, measurement and monitoring issues are emerging at the intersections of the project and national scales, referred to here as monitoring-domain edge effects. The following actions are necessary to improve existing monitoring capabilities and to help resolve project/national edge effects: (1) consensus on standard methods and protocols for monitoring mitigation activities, their off-site greenhouse gas (GHG) impacts, the fate of forest products and their relation to national GHG inventories (baselines); (2) a global program for collecting land use, land cover, biomass burning, and other data essential for national baselines; (3) the development of new nested-monitoring-domain methods that allow projects to be identified in national GHG inventories (baselines), and permit tracking of leakage of GHGs and wood product flows outside project boundary and over time; and (4) presentation of a set of credible, carefully designed, and well-documented forest mitigation activities that resolve most of the current issues.     

宿州市表层土壤重金属元素环境地球化学基线研究

环境地球化学基线作为能够判别自然和人为环境影响的地球化学指标,不同地区基线值的确定具有重要的现实意义和参考价值。本研究以宿州市为例,通过野外采样和室内测试,对表层土壤中的Cu、Zn、Pb、As、Cr、V六种重金属元素进行总量分析,采用标准化方法和相对累积频率分析方法计算确定宿州市土壤环境地球化学基线,基于确定的地球化学基线值,运用地质累积指数法对宿州市表层土壤重金属污染进行环境地球化学评价。结果表明,研究区表层土壤中Cu、Zn、Pb、As、Cr、V的平均含量分别为18.29、52.61、20.84、10.29、69.83和82.27 mg/kg;确定的环境地球化学基线值分别为16.97、48.66、19.43、9.07、65.22和79.08 mg/kg,获得的基线值符合其定义和实际意义;地质累积指数计算分析结果显示,六种重金属元素大部分处于无污染级别,少量达到无污染到中度污染级别,六种重金属元素在表层土壤中的富集贫化不明显。     

Baseline Standardisation with Optimising Energy-System Models

Determining adequate baselinesis a major methodological problem whenquantifying emissions reductions achievedwith the project-based flexibilitymechanisms. Possible methodologies forbaseline setting may be classified intomulti-project and project-specificapproaches. While multi-project approachesprovide baselines for a series of typicalprojects within a certain geographicregion, a sector, or a load range,project-specific (orproject-by-project/single-project)approaches only cover one specific project.Project-by-project baseline approaches havebeen tested extensively within theActivities Implemented Jointly (AIJ) pilotphase; multi-project methodologies, on theother hand, have only rarely been applieddue to the (perceived) political andeconomic complexity of the issue, whichmakes the process of introducingstandardised baselines a very sensitivetask. In particular, there is a lack ofmulti-project baseline approaches takingadvantage of optimising computer modelswithin the electricity sector, even thoughother fields of research have made use ofsuch models quite successfully in the past.Experiences made in the PROBASE projectwith the calculation of standardised,aggregated multi-project baselines forJI/CDM projects using optimising energysystem models are illustrated in this paperfor South Africa, Russia, and Indonesia.Increased transparency and credibility ofstandardised approaches along withpotentially lower transaction costs areidentified as the main arguments for theiruse and further development. In addition,the text gives recommendations wheremodel-based baseline standardisation canpreferentially be applied.     

Land use change and forestry climate project regional baselines: a review

Climate change programs have largely used the project-specific approach for estimating baseline emissions of climate mitigation projects. This approach is subjective, lacks transparency, can generate inconsistent baselines for similar projects, and is likely to have high transaction costs. The use of regional baselines, which partially addresses these issues, has been reported in the literature on forestry and agriculture projects, and in greenhouse gas (GHG) mitigation program guidance for them (e.g., WRI/WBCSD GHG Project Protocol, USDOE’s 1605(b) registry, UNFCCC’s Clean Development Mechanism). This paper provides an assessment of project-specific and regional baselines approaches for key baseline tasks, using project and program examples. The regional experience to date is then synthesized into generic steps that are referred to as Stratified Regional Baselines (SRB). Regional approaches generally, and SRB in particular explicitly acknowledge the heterogeneity of carbon density, land use change, and other key baseline driver variables across a landscape. SRB focuses on providing guidance on how to stratify lands into parcels with relatively homogeneous characteristics to estimate conservative baselines within a GHG assessment boundary, by applying systematic methods to determine the boundary and time period for input data.

Institutional and cost implications of multi-project baselines

Starting from a theoreticalnotion of capacity building this paperfocuses on the implications ofmulti-project baselines for costs andinstitutions. Availability of data and thelevel of data aggregation determine to alarge extent the cost of derivingmulti-project baselines. For localinstitutions this implies that theircapacity development needs are linked todecisions made on strictness of baselines.The initial higher costs of multi-projectcalculations in the development stage areeasily offset once more projects will usesuch a baseline. This paper argues theseinitial demands are not as high asexpected. Multi-project approaches willreduce transaction costs, especially forsmall-scale projects, will reducevalidation costs and likely reduce humanresource demands in other stages of theproject cycle.     

区域尺度土壤环境地球化学基线估算方法及其应用研究

区域土壤环境地球化学基线可为区域尺度地球表层系统中物质变化提供丰富的数据信息,并可据此评价自然和人为活动对土壤环境中化学物质浓度变化的影响.本研究以长江、珠江三角洲地区As、Cd、Hg、Pb、Se等10种微量元素的土壤环境地球化学基线为例,探讨了运用累积频率曲线法和土壤面积加权平均法分别估算了不同类别土壤和整个区域土壤的环境地球化学基线,取得了较为一致的结果.并通过基线比较反映地球化学富集作用和人为活动对土壤环境中微量元素积累与污染的影响.较为典型的是近20年来珠江三角洲地区农业土壤中Cd由过去0.035mg/kg增加到目前的0.13～0.22mg/kg,Hg也由过去的0.045mg/kg增加到目前的0.15mg/kg左右,区域化污染趋势已经显现.     

e-Serem – A Web-Based Manual For The Estimation of Emission Reductions From JI and CDM Projects

This paper presentse-SEREM (Smart Emission ReductionEstimation Manual), a cost-free, easilyaccessed and updated, web-based manual forestimating emission reductions from Joint Implementation (JI) andClean Development Mechanism (CDM) projects. e-SEREM's main functions arethe selection of a benchmark for a specificproject type in the power or heat sectorand the calculation of the annual andcumulative emission reductions accrued bythis project for its crediting lifetime.e-SEREM was developed in order to test itsapplicability and practicality in assistingproject developers and evaluators toelaborate baselines easily and calculatethe emission credits earned by candidate JIor CDM projects hosted in several countries.     

Baselines for land-use change in the tropics: application to avoided deforestation projects

Although forest conservation activities, particularly in the tropics, offer significant potential for mitigating carbon (C) emissions, these types of activities have faced obstacles in the policy arena caused by the difficulty in determining key elements of the project cycle, particularly the baseline. A baseline for forest conservation has two main components: the projected land-use change and the corresponding carbon stocks in applicable pools in vegetation and soil, with land-use change being the most difficult to address analytically. In this paper we focus on developing and comparing three models, ranging from relatively simple extrapolations of past trends in land use based on simple drivers such as population growth to more complex extrapolations of past trends using spatially explicit models of land-use change driven by biophysical and socioeconomic factors. The three models used for making baseline projections of tropical deforestation at the regional scale are: the Forest Area Change (FAC) model, the Land Use and Carbon Sequestration (LUCS) model, and the Geographical Modeling (GEOMOD) model. The models were used to project deforestation in six tropical regions that featured different ecological and socioeconomic conditions, population dynamics, and uses of the land: (1) northern Belize; (2) Santa Cruz State, Bolivia; (3) Paraná State, Brazil; (4) Campeche, Mexico; (5) Chiapas, Mexico; and (6) Michoacán, Mexico. A comparison of all model outputs across all six regions shows that each model produced quite different deforestation baselines. In general, the simplest FAC model, applied at the national administrative-unit scale, projected the highest amount of forest loss (four out of six regions) and the LUCS model the least amount of loss (four out of five regions). Based on simulations of GEOMOD, we found that readily observable physical and biological factors as well as distance to areas of past disturbance were each about twice as important as either sociological/demographic or economic/infrastructure factors (less observable) in explaining empirical land-use patterns. We propose from the lessons learned, a methodology comprised of three main steps and six tasks can be used to begin developing credible baselines. We also propose that the baselines be projected over a 10-year period because, although projections beyond 10 years are feasible, they are likely to be unrealistic for policy purposes. In the first step, an historic land-use change and deforestation estimate is made by determining the analytic domain (size of the region relative to the size of proposed project), obtaining historic data, analyzing candidate baseline drivers, and identifying three to four major drivers. In the second step, a baseline of where deforestation is likely to occur–a potential land-use change (PLUC) map—is produced using a spatial model such as GEOMOD that uses the key drivers from step one. Then rates of deforestation are projected over a 10-year baseline period based on one of the three models. Using the PLUC maps, projected rates of deforestation, and carbon stock estimates, baseline projections are developed that can be used for project GHG accounting and crediting purposes: The final step proposes that, at agreed interval (e.g., about 10 years), the baseline assumptions about baseline drivers be re-assessed. This step reviews the viability of the 10-year baseline in light of changes in one or more key baseline drivers (e.g., new roads, new communities, new protected area, etc.). The potential land-use change map and estimates of rates of deforestation could be re-done at the agreed interval, allowing the deforestation rates and changes in spatial drivers to be incorporated into a defense of the existing baseline, or the derivation of a new baseline projection.     

Assessing trophic position from nitrogen isotope ratios: effective calibration against spatially varying baselines

Nitrogen isotope signatures (δ¹⁵N) provide powerful measures of the trophic positions of individuals, populations and communities. Obtaining reliable consumer δ¹⁵N values depends upon controlling for spatial variation in plant δ¹⁵N values, which form the trophic ‘baseline’. However, recent studies make differing assumptions about the scale over which plant δ¹⁵N values vary, and approaches to baseline control differ markedly. We examined spatial variation in the δ¹⁵N values of plants and ants sampled from eight 150-m transects in both unlogged and logged rainforests. We then investigated whether ant δ¹⁵N values were related to variation in plant δ¹⁵N values following baseline correction of ant values at two spatial scales: (1) using ‘local’ means of plants collected from the same transect and (2) using ‘global’ means of plants collected from all transects within each forest type. Plant δ¹⁵N baselines varied by the equivalent of one trophic level within each forest type. Correcting ant δ¹⁵N values using global plant means resulted in consumer values that were strongly positively related to the transect baseline, whereas local corrections yielded reliable estimates of consumer trophic positions that were largely independent of transect baselines. These results were consistent at the community level and when three trophically distinct ant subfamilies and eight abundant ant species were considered separately. Our results suggest that assuming baselines do not vary can produce misleading estimates of consumer trophic positions. We therefore emphasise the importance of clearly defining and applying baseline corrections at a scale that accounts for spatial variation in plant δ¹⁵N values.     

后京都时代全球碳排放权配额分配模拟研究

采用自底向上和自顶向下两种建模方法,构建了一个全球碳排放权配额分配模型.通过对排放水平控制方案、单一原则方案和加权原则方案的情景模拟和分析,结果发现:当前全球试图通过气候谈判制定的减排方案是一种排放水平控制方案.由于在减排方式、基准年份和减排比例方面各国仍无法统一,该方案具有很大的不确定性.虽然单一原则方案可在某一指标上体现公平,但各区域对不同原则的偏好程度差异悬殊,甚至在某些原则下可能出现极端的分配结果,如人均累计碳排放均等原则.与前两类方案相比,加权原则方案更具公平性、可行性、可扩展性和可操作性.实施加权原则方案应尽可能多地涵盖不同原则,并以投票方式决定相关原则权重.     

浙江平湖农田土壤安全质量评价

以Al元素作为标准化元素求得平湖地区农田土壤重金属基线值,用单因子指数法进行土壤质量评价,结果表明该地区表层土壤均受到不同程度的轻微重金属污染,6%土壤为中度Hg污染;内梅罗综合污染指数显示土壤作物已经受到了污染,但程度不严重.     

渤海沿岸底栖贝类体内微污染物残留

依据第二次海洋污染基线调查数据以确定渤海沿岸站位底栖贝类体内重金属和有机污染物含量范围和分布特征.结果表明,沿岸贝类体内Cd的含量普遍较高,而As、Hg和Pb的浓度水平大多较低.辽东湾沿岸贝类体内检测到较高的DDT显示附近区域有新的DDT输入.PCBs的生物残留量以莱州湾近岸为最高,其次是渤海湾近岸;酞酸酯的生物残留主要出现在莱州湾和辽东湾沿岸站位.渤海沿岸大部分站位贝类体内DDTs组份含量已超出相应的USEPA人体健康和野生动物的质量基准,应予以关注.     

Methods for project-based mechanisms (JI/CDM)—relevance of IPCC inventory guidelines

A baseline for a project consists of estimates of annual emissions of greenhouse gases (GHG) for a given time period without implementing the project. A general three-step process for determining the baseline is suggested. The emission reduction of the project is given by the difference between the baseline and the monitored annual emissions. A preferred method, direct measurement of the emission reduction, is possible for some types of projects. Methods for estimating the annual baseline emissions are not necessary for the latter category, and a definition of this project category is suggested. IPCC Guidelines for National GHG Inventories categorise the emission sources so that only direct emissions from consumption of fuel and feedstock are calculated. There are thus no emission factors for indirect emissions (e.g. electricity consumption or km transported) or emission factors that depend on technology only, independent of consumption of fuel and feedstock. Technology-dependent emission factors may thus need to be developed for estimating indirect emissions and multi-project baselines. Consistency should be sought with the IPCC Guidelines when estimating annual baseline emissions and in monitoring project emissions to ensure comparability with the National Inventories.     

Sensitivity of amounts and distribution of tropical forest carbon credits depending on baseline rules

One of the largest sources of global greenhouse gas emissions can be addressed through conservation of tropical forests by channeling funds to developing countries at a cost-savings for developed countries. However, questions remain to be resolved in negotiating a system for including reduced emissions from deforestation and forest degradation (REDD) in a post-Kyoto climate treaty. The approach to determine national baselines, or reference levels, for quantifying REDD has emerged as central to negotiations over a REDD mechanism in a post-Kyoto policy framework. The baseline approach is critical to the success of a REDD mechanism because it affects the quantity, credibility, and equity of credits generated from efforts to reduce forest carbon emissions. We compared outcomes of seven proposed baseline approaches as a function of country circumstances, using a retrospective analysis of FAO-FRA data on forest carbon emissions from deforestation. Depending upon the baseline approach used, the total credited emissions avoided ranged over two orders of magnitude for the same quantity of actual emissions reductions. There was also a wide range in the relative distribution of credits generated among the five country types we identified. Outcomes were especially variable for countries with high remaining forest and low rates of deforestation (HFLD). We suggest that the most credible approaches measure emissions avoided with respect to a business-as-usual baseline scenario linked to historic emissions data, and allow limited adjustments based on forest carbon stocks.     

Concerns about climate change mitigation projects: summary of findings from case studies in Brazil,India, Mexico and South Africa

The concept of joint implementation as a way to implement climate change mitigation projects in another country has been controversial ever since its inception. Developing countries have raised numerous issues at the project-specific technical level and broader concerns having to do with equity and burden sharing. This paper summarizes the findings of studies for Brazil, India, Mexico and South Africa, four countries that have large greenhouse gas emissions and are heavily engaged in the debate on climate change projects under the Kyoto Protocol. The studies examine potential or current projects/programs to determine whether eight technical concerns about joint implementation can be adequately addressed. They conclude that about half the concerns were minor or well managed by project developers, but concerns about additionality of funds, host country institutions and guarantees of performance (including the issues of baselines and possible leakage) need much more effort to be adequately addressed. All the papers agree on the need to develop institutional arrangements for approving and monitoring such projects in each of the countries represented. The case studies illustrate that these projects have the potential to bring new technology, investment, employment and ancillary socioeconomic and environmental benefits to developing countries. These benefits are consistent with the goal of sustainable development in the four study countries. At a policy level, the studies' authors note that in their view, the Annex I countries should consider limits on the use of jointly implemented projects as a way to get credits against their own emissions at home, and stress the importance of industrialized countries developing new technologies that will benefit all countries. The authors also observe that if all countries accepted caps on their emissions (with a longer time period allowed for developing countries to do so) project-based GHG mitigation would be significantly facilitated by the improved private investment climate.     

Development of regional climate mitigation baseline for a dominant agro-ecological zone of Karnataka,India

Setting a baseline for carbon stock changes in forest and land use sector mitigation projects is an essential step for assessing additionality of the project. There are two approaches for setting baselines namely, project-specific and regional baseline. This paper presents the methodology adopted for estimating the land available for mitigation, for developing a regional baseline, transaction cost involved and a comparison of project-specific and regional baseline. The study showed that it is possible to estimate the potential land and its suitability for afforestation and reforestation mitigation projects, using existing maps and data, in the dry zone of Karnataka, southern India. The study adopted a three-step approach for developing a regional baseline, namely: (i) identification of likely baseline options for land use, (ii) estimation of baseline rates of land-use change, and (iii) quantification of baseline carbon profile over time. The analysis showed that carbon stock estimates made for wastelands and fallow lands for project-specific as well as the regional baseline are comparable. The ratio of wasteland Carbon stocks of a project to regional baseline is 1.02, and that of fallow lands in the project to regional baseline is 0.97. The cost of conducting field studies for determination of regional baseline is about a quarter of the cost of developing a project-specific baseline on a per hectare basis. The study has shown the reliability, feasibility and cost-effectiveness of adopting regional baseline for forestry sector mitigation projects.

重庆市农地重金属基线值的厘定及其积累特征分析

为了确定重庆市农地土壤重金属基线值,了解重金属积累情况,明确优先控制元素,本研究基于地球化学基线原理,根据分层抽样采集6个土壤类型的表层土样共214个;在严格质量控制下,测定各个样品As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的含量.采用数理统计法、迭代剔除法和累积频率曲线法确定8种重金属的基线值,并应用地球化学基线因子污染指数法和地质累积指数法评估了重庆市农地土壤重金属积累状况.结果表明,重庆市农地土壤As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的基线值分别为5. 83、0. 25、66. 78、25. 45、0. 069、29. 90、26. 18、78. 44 mg·kg~(-1).地球化学基线因子指数法评估表明土壤As、Hg、Zn积累最为突出,分别有14. 65%、11. 82%、3. 88%样点达重度积累;地质累积指数法评估表明Cd、Cr、Cu、Ni、Pb超过93%的样点处于无积累,Hg、Zn、As轻度积累比例分别为26. 60%、21. 84%、21. 21%,仅As和Zn有5. 56%和0. 49%的样点为中度积累.水稻土、紫色土与潮土、黄壤、石灰岩土相比重金属积累程度轻.渝东北大巴山石灰岩中低山区、渝东南武陵山石灰岩低山区As、Zn点位积累率较高,渝西窟窿丘陵台地区、渝中中高丘平行岭谷区Hg、As点位积累率较高.两种评估方法均表明重庆市农地土壤主要积累重金属为As,其次为Hg、Zn,应加强管理防范.