Abstract: Broadly conceived and considered in its many usages, sustainability has grave defects as a planning goal, particularly when used by conservationists: it confuses means and ends; it is vague about what is being sustained and who or what is doing the sustaining; it is uninspiring; it is little more than Pinchot-era conservation (and thus ignores the many lessons learned since then); it need not be linked to land, to the land's functioning, or to any ecological science; it need not include a moral component; it is consistent with the view of humans as all-powerful manipulators of the planet; and, in general, it is such a malleable term that its popularity provides only a facade of consensus. When sustainability is defined broadly to include the full range of economic and social aspirations, it poses the particular risk that ecological and biodiversity concerns will be cast aside in favor of more pressing human wants. Given these many defects, the conservation movement should discard the term in favor of a more alluring goal, attentive to nature and its ecological functioning. A sound goal would incorporate and distill the considerable ecological and moral wisdom accumulated since Pinchot's day while giving conservationists the rhetorical tools needed to defend the land against competing pressures. In our view, conservation would be well served by an updated variant of "land health," Aldo Leopold's ecologically grounded goal from the 1940s. Land health as an independent understanding should set the essential terms of how we live and enjoy the earth, providing the framework within which we pursue our many social and economic aims. 相似文献
We analyzed 13 years of hourly measurements of SO2, NOx, and O3, at forest ecosystem research sites in SE Germany. A quasi-continuous data record was obtained by combining data sets from
two locations. Before interpreting trends in the combined data set, we analyzed if the change of location introduced a systematic
bias. We employed autocorrelation functions, Hurst statistics, complexity analysis, and recurrence quantification and found
that the partial data sets exhibited no indication of the presence of any bias. For SO2, we also compared the data from the forest sites with data obtained in nearby cities and also found no indications for any
systematic effects. Applying nonparametric trend statistics we found a significant decrease of the SO2. Most of the observed decrease is due to the reductions of SO2 emissions in eastern Germany, but reductions in western Germany and the Czech Republic also played important roles. For O3, we observed a significant increase, the causes of which are unclear from our data alone. No trend was identified for NOx. 相似文献
Measurements of urban air quality at monitoring stations in developed countries have frequently involved the criteria gaseous
pollutants, particulates, hazardous air pollutants, perceived air quality and relevant meteorological conditions. Large numbers
of indicators have therefore been established to quantify emissions, concentrations and environmental and human health impacts
of each of these groups of substances. To simplify the data for management, several indicators have been grouped together
to form urban air quality indices but the weightings of individual variables is contentious.
In industrialising and developing countries, data may be limited and traditional air pollutant indicators cannot often be
constructed. The emphasis therefore has to be placed on the development of policy-relevant indicators, such as Response Indicators
that reflect different policy principles for regulating air pollutant emissions. Indices that quantify the air quality management
capabilities and capacities at the city level provide further useful decision-relevant tools. Four sets of indices, namely,
1. air quality measurement capacity, 2. data assessment and availability, 3. emissions estimates, and 4. management enabling
capabilities, and a composite index to evaluate air quality management capability, were constructed and applied to 80 cities.
The indices revealed that management capability varied widely between the cities. In some of the cities, existing national
knowledge on urban air quality could have been more effectively used for management.
It was concluded that for effective urban air quality management, a greater emphasis should be given, not just to monitoring
and data capture programmes, but to the development of indicators and indices that empower decision-makers to initiate management
response strategies. Over-reliance on restricted, predetermined sets of traditional air quality indicators should be avoided. 相似文献
Environmental safety data are presented for [S,S]-Ethylene Diamine Disuccinate ([S,S]EDDS), a new, biodegradable, strong transition metal chelator. An environmental risk assessment for its use in detergent applications, which takes into account the chelating properties of [S,S]-EDDS, is proposed.
A property of [S,S]-EDDS that distinguishes it from other strong transition metal chelators is its, “ready” and transparent (no recalcitrant metabolites) biodegradation profile. Because its sorption to activated sludge solids is low ( Kp of 40 1/kg), removal of [S,S]EDDS during sewage treatment, which is greater than 96% as determined by the Continuous Activated Sludge test , is mainly ascribed to biodegradation. At projected use volumes in detergent applications [S,S] - EDDS predicted steady-state concentration in rivers leaving the mixing zone will be below 5 pg/I due to rapid biodegradation. [S,S]-EDDS exhibits low toxicity to fish and Daphnia ( both EC50s> 1000 mg/l). By contrast, due to limitation of the algal test for chelators apparent toxicity was observed (EC50 = 0.290 mg/l, NOEC - No observable Effect Concentration = 0.125 mg/l). Schowanek et al. [1] demonstrated that this is not toxicity sensu stricto but a chelation effect of trace metals in the test medium and of resulting essential nutrients limitation. This requires specific attention when the results of algal toxicity are to be extrapolated to a field situation to perform realistic risk assessment. Metal speciation calculations, using MINEQL+, show that at the predicted environmental concentrations of [S,S] - EDDS (1–5 μg/l), such a chelation effect would be insignificant. These calculations allow to estimate the NOEC for chelation effects in the field to be in the range of 0.250-0.500 mg/l, depending on the background water chemistry. These values are well above the laboratory NOEC.
An environmental risk assessment was performed using the EUSES (1.0) program. EUSES is currently the EU recommended tool for conducting risk assessments (TGD 1995). It was applied to estimate the river water and soil concentrations from production, formulation and private use life stages. The estimated PEC/PNEC ratio in all relevant environmental compartments is smaller than 1, indicating “no immediate concern” at the anticipated usage level. 相似文献