基于SSBM-ESDA模型的安徽省县域农业效率时空演变

以绿色农业发展为导向,选择农业碳排放作为非期望产出指标,采用超效率的SSBM模型和探索性空间数据分析(ESDA)相结合的方法,以县域单元为尺度对2000-2017年安徽省农业效率水平、空间格局及其演变趋势进行实证分析。研究发现:①传统DEA模型忽视了农业碳排放等非期望产出的负面效应,从而高估农业资源利用的实际状态,基于超效率的SSBM模型更符合实际情况,能较好地识别各评价单元之间的优劣关系。②研究期内,安徽省农业效率值呈波动式上升态势,但总体上处于效率中等水平,农业效率空间分布不均衡,呈现出皖南地区>皖中地区>皖北地区的空间分布格局;空间变化趋势呈现自西向东递增、自北向南U型增长的变化态势,南北差异的增大是安徽省县(市、区)农业效率差异增大的主导因素。③除2010年外,安徽省农业效率呈正相关,空间差异有所缩小,但空间集聚程度相对较弱;安徽农业效率HH集聚县区集中分布于皖南地区,且呈现出向周边县区扩散的态势,LL型县(市、区)则主要分布在皖北地区,且空间分布较为稳定。④研究期内,安徽省农业效率空间正相关的县(区)数量有所增加,表明该时间段内安徽省农业效率空间上进一步集聚,LL型集聚的皖北地区应当是安徽省农业发展关注的重点。     

城市森林固定CO2价值评估

本文利用我国第四次森林资源清样调查资料对上海市森林植被碳储量和碳密度的估算结果,结合植物的光合作用过程计算上海市森林固定CO2的能力,采用造林成本法对上海市森林固定CO2的价值进行了评估。笔者希望通过该研究激发人们保护城市森林以维持城市生态系统可持续发展的积极性,并为合理地进行城市森林管理和城市绿化提供参考。另外,利用系统连续的森林资源清样调查资料评估森林植被的固碳价值,能够对我国更好地履行《联合国气候变化框架公约(》UNFCCC),并为依据《京都议定书(》KyotoProtocol)进行环境外交提供帮助。     

上海市生态可持续发展评价研究

本文利用生态足迹法对上海市1985～2004年的生态足迹和生态承载力进行了研究，结果表明上海市入均生态足迹和生态承载力分别由1985年的1．9340hm^2、0．1582hm^2逐年增加至2004年的3．0459hm^2、0．5805hm^2，一而同期的入均生态赤字也由1．7958hm^2上升到2．6656hm^2。同时计算了万元GDP生态足迹，并预测了2010年的入均生态足迹和生态承载力。最后得出，上海市入口对自然资源的利用逐年增加，目前已超出了自然生态系统的生态承载力范围，现有的发展模式是不可持续的。     

资源型城市转型与循环经济发展--以黑龙江省伊春市为例

随着人类对资源的不断利用,资源型城市大都面临着转型问题,如何实现资源型城市的可持续发展,既是一个需要研究的理论问题,更是一个亟待解决的实际问题。通过伊春市经济资本和技术资本发展困境分析,采用生态足迹方法计算了资源型城市伊春市2003年的生态足迹,得出此地区尚未出现生态赤字,但对它的转型却迫在眉睫,据此提出了伊春市应向循环经济型生态城市转型的思路及实现路径和方法。     

基于生态足迹模型的可持续性度量研究--以吉林省大安市为例

针对吉林省大安市发展现状和存在的严重生态环境问题,运用生态足迹模型,采用多源数据,首次对大安市生态环境的可持续发展状况进行了定量研究;在此基础上,运用相对指标法对可持续发展的量化结果进行分级。研究表明,2001年大安市的生态需求大于生态供给,生态呈现“供不应求”的局面,人均生态赤字为0.56hm2,处于弱不可持续发展状态。     

河流水系与城市空间结构

河流水系是影响和制约城市空间结构的重要自然环境因素.文章在回顾河流水系与城市空间结构关系的基础上,针对现阶段我国水网城市①空间结构发展误区,对与河流水系融合共生的城市空间结构建构方法进行了有益探索.并以南阳市城区空间发展研究为例,提出在城市河流水系生态环境分析的基础上,保护性利用河流水系复合生态功能,挖掘潜在边缘效应,融入城市历史文化内涵,架构完整的城市空间格局.     

零售业上市公司业绩的DEA有效性分析

本文应用DEA模型对零售业上市公司的业绩进行了实证研究,通过DEA有效分析和规模收益分析对八家上市公司的业绩进行了效率衡量,为投资者理性投资提供了参考依据,也为上市公司提高效率提供了数据借鉴。     

Does Increased Extraction of Natural Gas Reduce Carbon Emissions?

Without an international climate agreement, extraction of more natural gas could reduce emissions of CO₂ as more clean natural gas may drive out dirty coal and oil. Using a computable equilibrium model for the Western European electricity and natural gas markets, we examine whether increased extraction of natural gas in Norway reduces global emissions of CO₂. We find that both in the short run and in the long run total emissions are reduced if the additional quantity of natural gas is used in gas power production in Norway. If instead the additional quantity is exported directly, total emissions increase both in the short run and in the long run. However, if modest CO₂-taxes are imposed, increased extraction of natural gas will reduce CO₂ emissions also when the additional natural gas is exported directed.earlier version of this paper was presented at the 25th Annual IAEE International Conference in Aberdeen June 2002.     

Indigenous livelihoods, slash-and-burn agriculture, and carbon stocks in Eastern Panama

Improved crop–fallow systems in the humid tropics can simultaneously sequester atmospheric carbon emissions and contribute to sustainable livelihoods of rural populations. A study with an indigenous community in eastern Panama revealed a considerable biophysical potential for carbon offsets in small-scale slash-and-burn agriculture through longer fallow periods, improved fallow management, secondary forest development, and agricultural intensification. Based on soil and biomass carbon measurements, estimated annual sequestration rates amount to 0.3−3.7 t C ha^− 1 yr^− 1. Despite such potential, the economic benefits of initiatives aimed at sequestration of carbon in the community are likely to be rather unequally distributed within the community. Heterogeneity in livelihood strategies and uneven asset endowments among households – factors often overlooked in the ongoing carbon and sustainable development debate – are expected to strongly affect household participation. Indeed, only the better-endowed households that have also managed to diversify into more lucrative farm and non-farm activities are likely to be able to participate in and thus benefit from improved crop–fallow systems that capture carbon. Economic, ethical, institutional, and technical concerns need to be taken into account when designing community carbon management and investment plans.     

Rethinking the costs related to global warming: A survey of the issues

One approach to the economic analysis of global warming seeks to balance the costs of damage from or adaptation to it with the costs of mitigating it. The costs of adaptation and damage have been estimated using techniques of environmental evaluation, but are subject to a wide margin of uncertainty. The costs of mitigation, principally by reducing the emissions of CO₂, have been estimated using different kinds of economic models, some of the results of which have suggested that very little abatement of carbon emissions is justified before the costs of abatement exceed the benefits of it in terms of foregone damage and adaptation costs. The paper analyses the extent to which this conclusion is a function of the modelling assumptions and techniques used, rather than likely practical outcomes, with regard to the models' treatment of unemployed resources, revenue recycling, prior distortions in the economy due to the tax system and possible dynamic effects from the introduction of a carbon-energy tax. It concludes that, with different and arguably more appropriate treatment of the above issues, especially when the secondary benefits of reducing CO₂ emissions are also taken into account, it is not clear that even substantial reductions in the use of fossil fuels will incur net costs, especially if there is the prospect of even moderate costs from global warming.