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31.
A simplistic aggregate model of global economic activity supports a 50-year visioning exercise with targets defined in terms of aggregate measures of global equity (convergence) and sustainability (contraction). Some ambitious combinations of these targets turn out to be infeasible even under the most favorable modeling assumptions. No contraction target (no reduction in fossil fuel consumption relative to the present) was possible, for example, if international capital transfers pushed per capita incomes in low-income countries above 33% of levels achieved in high-income countries. Lower prices for renewable alternatives to exhaustible resources generally made sustainability targets easier to achieve, but lower prices for renewable resources also made equity targets more difficult to achieve. Improved substitution between capital and labor made equity targets easier to achieve in relative terms, but improved substitution between capital and labor could make any given sustainability target more or less difficult to achieve. All the results suggest that it is possible to overstate the purported conflict between achieving sustainability and equity targets. The very transfers of international capital that would promote relative equity between high-income and low-income countries could also work to spread the incidence of achieving any sustainability target more evenly across their boundaries.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
32.
I. Lorenzoni A. Jordan D. Favis-Mortlock D. Viner J. Hall 《Regional Environmental Change》2001,2(3):106-117
The weight of scientific evidence suggests that human activities are noticeably influencing the world's climate. However,
the effects of global climate change will be unevenly spread, due to local variations in vulnerability and adaptive capacity.
Using downscaled projections of future UK climates over the next 50 years, this paper investigates the impacts of, and possible
responses to, climate change in one small area in eastern England, selected as a test-bed for sustainable agriculture. It
shows that local agricultural systems are vulnerable to changes in the climate. At present, however, these considerations
have a limited effect on agricultural operations, which are mainly driven by short-term events and 'non-climate' policies,
such as agricultural price support. The capacity of agricultural systems to adapt successfully to climate change will be determined
by the ability of producers to integrate climate change into their planning strategies with a view to ultimately ensuring
sustainable agricultural practices in the long term.
Electronic Publication 相似文献
33.
Jihoon Park Moon Seong Kang Inhong Song 《Journal of the American Water Resources Association》2015,51(3):859-876
The objective of this article was to assess flood vulnerability based on the representative concentration pathways (RCP) scenarios at city and county levels. A quantile mapping method was adopted to correct bias that is inherent in climate change scenarios. A series of proxy variables related to climate exposure, sensitivity, and adaptive capacity were chosen to assess flood vulnerability. Proxy variables were standardized using the Z‐score method. Principal component analysis was carried out to calculate the weighting of proxy variables. The study area was the Korean peninsula. The spatial resolution was on a city and county basis and the temporal resolution was 1990s, 2025s, 2055s, and 2085s (divided into 1976‐2005, 2011‐2040, 2041‐2070, and 2071‐2100). In the spatial comparison, we found that the areas with high‐level flood vulnerability increased over time in the central region, including metropolitan areas, and near the southern coast. In the temporal comparison, we found that the RCP4.5 scenario showed a tendency to increase steadily and the RCP8.5 scenario showed a tendency to decrease in the 2055s slightly and increase again in the 2085s. The study findings may provide useful data for the determination of priority for countermeasure development, though robustness of these findings with additional future projections should be established. 相似文献
34.
机动车数量的增加严重威胁城市环境,本文在不同减排情境下,开展城市机动车污染防治措施研究。使用清洁能源代替不可再生能源作为机动车动力燃料;明确责任制度,强化机动车管理体制,提升空气质量;布设城市监控设备优化交通结构,减少排放源;完善法律制度,协调经济发展与环保关系;发展公共交通,倡导绿色出行理念,降低城市机动车尾气排放污染。 相似文献
35.
研究以能源消费模式为切入点,分析中原经济区能源消费总量、消费结构和利用效率的现状水平,并分析能源消费引起的大气环境压力状况。基于经济发展速度调控及节能减排力度的不同,设置2020年三种能源消费情景,使用区域能源消费总量优化模型模拟预测不同情景下的能源消费总量,并分析不同情景下的大气环境压力。结果表明,快速发展和适度发展Ⅰ情景下,2020年区域能源消费总量将比2012年增加4.2×10~8tce和2.4×10~8tce,煤炭消费总量将增加3.1×10~8tce和1.2×10~8tce,大气污染物排放压力增加30%和50%;适度发展Ⅱ情景下,能源消费总量将增加0.2×10~8tce,煤炭消费总量将下降0.3×10~8tce,大气污染物排放压力将降低20%。因此,要实现经济发展稳步增长(年均增长率7.7%)和大气污染物排放总量削减10%目标,重中之重是实现煤炭消费总量"零增长"或"负增长",同时力争能源消费总量控制在5×10~8~6×10~8tce,凭借煤炭占比大幅下降(降至65%左右)最大限度发挥能源供给领域节能效应,依靠产业结构升级节能效应和技术节能拓展能源消费领域节能空间,将能效水平提高至0.6tce/万元以下。 相似文献
36.
Mats Lindegarth Ulf Bergström Johanna Mattila Sergej Olenin Markku Ollikainen Anna-Leena Downie Göran Sundblad Martynas Bučas Martin Gullström Martin Snickars Mikael von Numers J. Robin Svensson Anna-Kaisa Kosenius 《Ambio》2014,43(1):82-93
We evaluated performance of species distribution models for predictive mapping, and how models can be used to integrate human pressures into ecological and economic assessments. A selection of 77 biological variables (species, groups of species, and measures of biodiversity) across the Baltic Sea were modeled. Differences among methods, areas, predictor, and response variables were evaluated. Several methods successfully predicted abundance and occurrence of vegetation, invertebrates, fish, and functional aspects of biodiversity. Depth and substrate were among the most important predictors. Models incorporating water clarity were used to predict increasing cover of the brown alga bladderwrack Fucus vesiculosus and increasing reproduction area of perch Perca fluviatilis, but decreasing reproduction areas for pikeperch Sander lucioperca following successful implementation of the Baltic Sea Action Plan. Despite variability in estimated non-market benefits among countries, such changes were highly valued by citizens in the three Baltic countries investigated. We conclude that predictive models are powerful and useful tools for science-based management of the Baltic Sea. 相似文献
37.
Basic scenarios of sustainable development for the world community and approaches to the problem of ensuring food security
are discussed. The conservation of agricultural resources is the key element of food security. The structure and main objectives
of agroecology are characterized in brief. 相似文献
38.
Georgios K. Sylaios Vassilios A. Tsihrintzis 《Environmental Modeling and Assessment》2009,14(1):59-72
The nutrient dynamics of the Strymonikos and Ierissos Gulfs, two semienclosed coastal water bodies, are studied using a simple
steady-state budget model, according to the Land–Ocean Interaction in the Coastal Zone modeling guidelines. Strymon river
plume dynamics prevailed in the area of the Inner and Outer Srymonikos Gulfs, comprising two layers, while the Ierissos Gulf
was defined as a one-box system. Seasonal and mean annual model input data for river discharge, precipitation, evaporation,
and concentrations of salt, phosphorus, and nitrogen were obtained during four field campaigns. Results from the nitrogen
and phosphorus cycling revealed the importance of river discharge in the horizontal and vertical transport of these substances
within the system. Furthermore, it occurred that the major biogeochemical transformation of nitrogen and phosphorus takes
place in the immediate nearshore zone (Inner Strymonikos Gulf), while the outer system sustains its nutrient dependence on
oceanic exchanges. Therefore, under the summer low flow conditions, the river-influenced inner system acts as a net source
of nitrogen and phosphorus, while under increased Strymon River discharge, phosphorus is transferred to the biological material
(and the sediments), and the system moves to an autotrophic state. The outer system showed an opposite behavior being autotrophic
throughout the year and heterotrophic in February. The Ierissos Gulf, a system not directly influenced by significant river
discharge, experienced a seasonally independent behavior with net heterotrophic and denitrification processes prevailing.
Model scenarios demonstrated that phosphate concentration increases, even under low river flow conditions and stimulates primary
production in excess of respiration, resulting in nitrogen fixation prevalence in the Inner Strymonikos Gulf. 相似文献
39.
矿区不同复垦措施下土壤呼吸与环境因子关系的研究 总被引:2,自引:1,他引:2
为研究不同植被恢复方式和施肥处理下土壤呼吸的季节变化的影响因素,对山西省孝义市露天矿区复垦区土壤呼吸、温度和水分进行了2年的野外观测,采用不同单双变量模型分析了土壤呼吸与温度、水分间的关系.结果表明,植被恢复方式和施肥处理及其交互作用均显著影响土壤基础呼吸速率(R10)和土壤温度敏感性指数(Q10).在单变量模型分析中,百脉根和苜蓿草本恢复方式下,土壤呼吸与土壤温度间拟合水平较高,而油松林和混交林乔木恢复方式下,土壤呼吸与土壤水分间拟合水平较高;剔除土壤水分低于10%时的土壤呼吸值,可提高土壤呼吸与温度间拟合水平;对土壤呼吸值进行标准化,可提高土壤呼吸与水分间拟合水平.相较于其它施肥处理,有机肥处理的样地土壤呼吸与温度间拟合系数较高,而土壤呼吸与水分间的拟合系数较小.土壤呼吸与温度、水分间4个双因子模型的拟合系数因植被恢复方式和施肥不同而有所不同.总之,土壤呼吸与温度、水分间双变量模型比单变量模型可更准确预测土壤碳通量值. 相似文献
40.
系统总结了国内外用于评估重金属污染土壤稳定化修复效果的方法及存在的问题,目前国内外土壤稳定化效果评估多采用模拟填埋和酸雨情景下的毒性浸出方法,但该评估方法不能完全模拟基于填埋、绿化、路基和河岸护坡等不同用途和去向后污染物向环境中释放的多种情景,也很难表征碳化、冻融等实际复杂多变环境的长期作用下重金属释放的风险。应基于土壤稳定化处理后的不同用途和去向,建立相应的浸出方法,评估不同环境胁迫条件下重金属释放的可能性及浸出量,同时建立稳定化土壤的健康和生态风险评估方法以评价其存在的潜在风险,尝试构建稳定化土壤的浸出和风险评估方法体系。 相似文献