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1.
Genetically modified (GM) crops have been recognised to be economically beneficial to subsistence farmers and have been projected as essential tools for addressing challenges in hunger, environmental sustainability and international development. Yet the uncertainty of their effects on human health and the undesirable ecological consequences of these organisms have raised concerns on the rapid pace of their production. Regulating the release of these organisms is a critical environmental issue. The Cartagena protocol on bio-safety, the principle legal arrangement for the regulation of these organisms, has ratifications from only 157 countries and has proven to be a weak regulator. Countries like India and Brazil have seen the proliferation of unapproved stealth GM varieties which make regulation even more difficult. In this paper, we explore the debate surrounding the introduction of GM organisms and analyse the effectiveness of existing legal regimes to regulate their use.  相似文献   

2.
Conservation agriculture has successfully spread in a number of developing country contexts, resulting in both positive production and environmental impacts. However, there are ongoing questions about the appropriateness of conservation agriculture for small-scale farming as poor farmers tend to be risk averse, typically lack access to credit, and may have planning horizons associated with heavily discounted future benefits. This study investigates farmer attitudes toward how a hypothetical set of conservation agriculture production practices will affect yield, labor use, erosion, and cost in two communities of Bolivar province, Ecuador, through the implementation of a discrete choice experiment. Results show producers are most concerned with future yields, planting labor, and overall costs. While off-farm erosion impacts are of concern, producers only placed small values on these impacts. Results provide support for conservation agriculture outreach to highlight practices that increase long-run production and reduce the time and technical skills associated with planting.  相似文献   

3.
Urbanization is known to spur land modification in the form of conversion of common land to human settlements. This factor, combined with climate variability, can alter the duration, frequency and intensity of storm drain overflows in urban areas and lead to public health risks. In peri-urban regions where these risks are especially high it has been argued that, when domestic wastewater is managed, better prospects for freshwater water savings through swaps between urban water supply and irrigated agriculture may be possible. As a consequence of re-use of domestic wastewater, expenditure on inorganic inputs by farmers may decline and source sustainability of water supply could be enhanced. Given the fact that, at present, approximately 20 million ha of land worldwide is being cultivated by re-using domestic wastewater, this paper draws on evidence from India to explore: (1) the economic costs–benefits of wastewater reuse in the context of hypothesized links to climate variability; (2) the role of local farming practices, market conditions and crop variety in influencing wastewater reuse in agriculture; and (3) the role of inter-governmental financing in influencing the selection of technical adaptation options for collection, treatment and disposal of wastewater.  相似文献   

4.
Despite recent calls to limit future increases in the global average temperature to well below 2 °C, little is known about how different climatic thresholds will impact human society. Future warming trends have significant global food security implications, particularly for small island developing states (SIDS) that are recognized as being among the most vulnerable to global climate change. In the case of the Caribbean, any significant change in the region’s climate is likely to have significant adverse effects on the agriculture sector. This paper explores the potential biophysical impacts of a +?1.5 °C warming scenario on several economically important crops grown in the Caribbean island of Jamaica. Also, it explores differences to a >?2.0 °C warming scenario, which is more likely, if the current policy agreements cannot be complied with by the international community. We use the ECOCROP niche model to estimate how predicted changes in future climate could affect the growing conditions of several commonly cultivated crops from both future scenarios. We then discuss some key policy considerations for Jamaica’s agriculture sector, specifically related to the challenges posed to future adaptation pathways amidst growing climate uncertainty and complexity. Our model results show that even an increase less than +?1.5 °C is expected to have an overall negative impact on crop suitability and a general reduction in the range of crops available to Jamaican farmers. This observation is instructive as increases above the +?1.5 °C threshold would likely lead to even more irreversible and potentially catastrophic changes to the sustainability of Jamaica’s agriculture sector. The paper concludes by outlining some key considerations for future action, paying keen attention to the policy relevance of a +?1.5 °C temperature limit. Given little room for optimism with respect to the imminent changes that SIDS will need to confront in the near future, broad-based policy engagement by stakeholders in these geographies is paramount, irrespective of the climate warming scenario.  相似文献   

5.
Heavy metal concentrations were examined in surface sediments from 79 sites within the Altata-Ensenada del Pabellon lagoon system. Data were normalized to separate natural from anthropogenic factors using aluminum and lithium as conservative elements and following two different discriminating criteria. For the normalization process, the natural metal concentrations were assumed to vary consistently with aluminum and lithium, unless the metal contents were of human origin. Strong linear correlations (P < .001) were observed between the conservative elements and the metals measured. According to Szefer's normalizing criteria, about 90% of the polluted sites, for at least one metal, occurred near agricultural discharge drains. In accordance with the Muller [Umschau 79 (1979) 778.] scale, this lagoon system is subject to pollutant effects only with regard to Pb (moderately to strongly polluted). It was concluded that either Al and Li could be useful to normalize granulometric variability in heavy metal studies of these lagoon sediments, and that Summers' normalization criterion proved more rigorous than Szefer's for these types of sediments.  相似文献   

6.
The concentration of naturally occurring radionuclides 232Th, 238U was determined using Instrumental Neutron Activation Analysis (INAA) in different food groups namely cereals, vegetables, leafy vegetables, roots and tubers cultivated and consumed by tribal population residing around the proposed uranium mine. The study area is a part of rural area K. P. Mawthabah (Domiasiat) in the west Khasi Hills District of Meghalaya, India located in the tropical region of high rainfall that remains steeped in tribal tradition without much outside influence. Agriculture by Jhum (slash and burn) cultivation and animal husbandry are the main occupation of the tribal populations. A total of 89 samples from locally grown food products were analyzed. The concentration of 238U and 232Th in the soil of the study area was found to vary 1.6-15.5 and 2.0-5.0 times respectively to the average mean value observed in India. The estimated daily dietary intake of 238U and 232Th were 2.0 μg d−1 (25 mBq d−1) and 3.4 μg d−1 (14 mBq d−1) is comparable with reported range 0.5-5.0 μg d−1 and 0.15-3.5 μg d−1 respectively for the Asian population.  相似文献   

7.
Some important naturally occurring α- and β-radionuclides in drinking water samples collected in Italy were determined and the radiological quality evaluated. The mean activity concentrations (mBq L−1) of the radionuclides in the water samples were almost in the order: 26 ± 36 (234U) > 21 ± 30 (238U) > 8.9 ± 15 (226Ra) > 4.8 ± 6.3 (228Ra) > 4.0 ± 4.1 (210Pb) > 3.2 ± 3.7 (210Po) > 2.7 ± 1.2 (212Pb) > 1.4 ± 1.8 (224Ra) > 1.1 ± 1.3 (235U) > 0.26 ± 0.39 (228Th) > 0.0023 ± 0.0009 (230Th) > 0.0013 ± 0.0006 (232Th). The mean estimated dose (μSv yr−1) to an adult from the water intake was in this order: 2.8 ± 3.3 (210Po) > 2.4 ± 3.2 (228Ra) > 2.1 ± 2.1 (210Pb) > 1.8 ± 3.1 (226Ra) > 0.94 ± 1.30 (234U) > 0.70 ± 0.98 (238U) > 0.069 ± 0.087 (224Ra) > 0.036 ± 0.044 (235U) > 0.014 ± 0.021 (228Th) > 0.012 ± 0.005 (212Pb) > 0.00035 ± 0.00029 (230Th) > 0.00022 ± 0.00009 (232Th). It is obvious that 210Po, 228Ra, 210Pb and 226Ra are the most important dose contributors in the drinking water intake. As far as the seventeen brands of analysed drinking water were concerned, the committed effective doses were in the range of 2.81–38.5 μSv yr−1, all well below the reference level of the committed effective dose (100 μSv yr−1) recommended by the WHO. These data throw some light on the scale of the radiological impact on the public from some naturally occurring radionuclides in drinking water, and can also serve as a comparison for the dose contribution from artificial radionuclides released to the environment as a result of human practices. Based on the radionuclide composition in the analysed waters, comment was made on the new screening level for gross α activity in guidelines for drinking-water quality recommended by the WHO, 2004.  相似文献   

8.
The objective of this study was to provide operational probability density functions (PDFs) for distribution coefficients (Kds) in freshwater, representing the partition of radionuclides between the particulate and the dissolved phases respectively. Accordingly, the Kd variability should be considered in uncertainty analysis of transport and risk assessment models. The construction of PDFs for 8 elements (Ag, Am, Co, Cs, I, Mn, Pu and Sr) was established according to the procedure already tested in Durrieu et al. [2006. A weighted bootstrap method for the determination of probability density functions of freshwater distribution coefficients (Kds) of Co, Cs, Sr and I radioisotopes. Chemosphere 65 (8), 1308–1320]: (i) construction of a comprehensive database where Kds values obtained under various environments and parametric conditions were collected; (ii) scoring procedure to account for the ‘quality’ of each datapoint (according to several criteria such as the presentation of data (e.g. raw data vs mean with or without replicates), contact time, pH, solid-to-liquid ratio, expert judgement) in the construction of the PDF; (iii) weighted bootstrapping procedure to build the PDFs, in order to give more importance to the most relevant datapoints. Two types of PDFs were constructed: (i) non-conditional, usable when no knowledge about the site of concern is available; (ii) conditional PDFs corresponding to a limited range of parameters such as pH or contact time; conditional PDFs can thus be used when some parametric information is known on the site under study. For 7 other radionuclides (Ba, Be, Ce, Ra, Ru, Sb and Th), a simplified procedure was adopted because of the scarcity of data: only non-conditional PDFs were built, without incorporating a scoring procedure.  相似文献   

9.
New best estimates for the solid–liquid distribution coefficient (Kd) for a set of radionuclides are proposed, based on a selective data search and subsequent calculation of geometric means. The Kd best estimates are calculated for soils grouped according to the texture and organic matter content. For a limited number of radionuclides this is extended to consider soil cofactors affecting soil–radionuclide interaction, such as pH, organic matter content, and radionuclide chemical speciation. Correlations between main soil properties and radionuclide Kd are examined to complete the information derived from the best estimates with a rough prediction of Kd based on soil parameters. Although there are still gaps for many radionuclides, new data from recent studies improve the calculation of Kd best estimates for a number of radionuclides, such as selenium, antimony, and iodine.  相似文献   

10.
In his keynote address, Robert Cox raised key questions, many of which force us to consider the larger question of the role of academics in society. The authors respond by suggesting that environmental communication, like other communication studies, is inherently normative and that environmental communication scholarship is closely aligned to risk as a centerpiece to crisis analysis. The authors discuss the productive connections among science, communication and sound public policy that make society more fully functional, including the formation of effective public policy through science that is normative while seeking objectivity, evaluating and symbolizing motives in discourse, acknowledging uncertainty and acceptable uncertainty, and that material and symbolic dimensions of the environment are interdependent. Thus, such studies focus on the ethics of environment and must balance sound science and cultural considerations.  相似文献   

11.
Cape Farewell is the brainchild of London-based artist David Buckland. The project is centered round a series of sailing voyages into the Arctic, through routes that were previously icebound but are now passable. The expeditions take teams of world-renowned artists, educators, writers, musicians and thinkers into the Arctic, onboard a hundred-year old schooner, with the invitation to engage with scientists (from the National Oceanography Centre, as well as Southampton), to make art, and to draw people's attention to the effects of ocean currents on us and our climate. Since its first expedition in 2003, the project has grown to include educational programs, an award-winning website, a BBC documentary, and an exhibit, “The Ship, The Art of Climate Change,” developed with the Natural History Museum and which has embarked on a worldwide tour. In August 2007, Cape Farewell began a three-year residency at Southbank Centre, operating as a cultural eco-hub for the Centre's creative climate change initiatives, and has started a collaboration with the Eden Project in Cornwall, UK.

This interview was conducted in the Cape Farewell offices, which are in David Buckland's studio atop his family home in Camden, London. Currently, Renée Lertzman is conducting a PhD in critical psychology studies at Cardiff University in Wales, UK. Her interviews and writings relating to environmental communication have appeared in The Sun Magazine, Orion, Land and People (Trust for Public Land), Speak Magazine, Terra Nova, and Organization & Environment. Lertzman can be contacted at http://www.reneelertzman.org. For more information about Cape Farewell, visit http://capefarewell.com.  相似文献   

12.
Contaminant input into the environment can affect the biochemical responses of exposed organisms. Activity of conjugation enzymes, such as glutathione S-transferase (GST) has been proposed as a biomarker of susceptibility to the presence of potentially damaging xenobiotics. The aim of the present study was to evaluate the activity of total and Pi-class GST in the hepatopancreas of pink-shrimp Farfantepenaeus brasiliensis. The shrimp were caught at a single site at Concei??o Lagoon and transplanted to another site (Canto da Lagoa - CA) in the same lagoon, and to the laboratory (LAB), where they were kept for 15 days. This experiment was carried out in winter 2003 and in summer 2004. Shrimp were sampled before the exposure, at a zero time (t0), and after 15-days at CA site and LAB. The activity of total GST and Pi-isoform were analyzed using CDNB and ethacrynic acid (EA) as substrates, respectively. Shrimp caught in winter showed higher levels of Pi-class GST than those caught in summer, for both t0 and CA groups. Moreover, differences in the activity of this GST isoform between groups were observed only in winter, where the animals from t0 and CA groups presented higher activity when compared to those kept in the laboratory. This difference could be associated either to changes in the contaminant input or to other water quality parameters in this ecosystem. The elevated GST Pi activity observed in the shrimp of both t0 and CA groups sampled in winter could be related to salinity, since it was higher in winter than in summer. We could also suggest a possible association of this finding to a seasonal metabolic variation in this penaeid. If that is the case, one should take into account these alterations when considering the use of this GST isoform as biomarker in F. brasiliensis in environmental monitoring programs.  相似文献   

13.
14.
It has been nearly 20 years since a working definition for “sustainable development” was put forward by the World Commission on Environment and Development. The concept endures in the mission statements and frameworks of action of various societal actors, including those of neighborhood associations, metropolitan development authorities, environmental ministries, and United Nations (UN) specialized organizations, to name a few. Yet many observers doubt that sustainable development is occurring in poor countries. This failure, the critics contend, stems from miserly transfers of foreign aid. The extent to which inadequate aid is to blame for poor environmental/developmental outcomes is an open question. But vocal demands for increasing aid to meet sustainable development goals come from many parts of society and are persistent. Exhortations for more aid to help poor countries are noble, perhaps even justifiable, but there are understandable doubts about the wisdom of transferring large capital and technical resources to countries that are slow to adopt needed institutional reforms. Aid without institutional reform is a recipe for wasted resources and donor fatigue. Worse, it may enhance inequities of wealth and power in recipient countries. There are few illustrations to draw on demonstrating how institutionally impoverished societies are affected when they are compelled to absorb massive aid inputs over a short period––a remedy suggested by some prominent aid experts. As a proxy, it is valuable to examine instances where swift macroeconomic changes, spurred by external investment and export-led growth, has occurred without significant institutional development. The case of Equatorial Guinea and its sudden oil riches is examined to discern whether, in the absence of meaningful institutional reform, rapid and profound increases in foreign direct investment and export income enable poverty alleviation and sustainable development.
Matthew R. AuerEmail:
  相似文献   

15.
This paper discusses the linkages between population change, land use, and deforestation in the Amazon regions of Brazil, Bolivia, Colombia, Ecuador, Perú, and Venezuela. We begin with a brief discussion of theories of population–environment linkages, and then focus on the case of deforestation in the PanAmazon. The core of the paper reviews available data on deforestation, population growth, migration and land use in order to see how well land cover change reflects demographic and agricultural change. The data indicate that population dynamics and net migration exhibit to deforestation in some states of the basin but not others. We then discuss other explanatory factors for deforestation, and find a close correspondence between land use and deforestation, which suggests that land use is loosely tied to demographic dynamics and mediates the influence of population on deforestation. We also consider national political economic contexts of Amazon change in the six countries, and find contrasting contexts, which also helps to explain the limited demographic-deforestation correspondence. The paper closes by noting general conclusions based on the data, topics in need of further research and recent policy proposals.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue  相似文献   

16.
Place branding strategies play a significant role in the professional composition of landscape imagery, including the depiction of “natural” landscapes. In this paper, Brand Blue Mountains, a brand currently implemented in the Blue Mountains region (Australia), is discursively analyzed. The brand sets out an all-encompassing “Vision” defining the identity, values and personality of the World Heritage listed Blue Mountains landscape, summarized in the tagline Elevate Your Senses. This “vision” is visually translated into a strictly coordinated and copyrighted suite of logos, graphic design, color, fonts and various photographic styles. Analysis reveals that the degree of control that place brand strategists seek to exert over the visual expression of landscape identity is significant. A highly selective narrative of positive nature-based sensory experience is constructed through the holistic application of contemporary visual media. The brands' communications strategy naturalizes and reinforces a particular market-friendly version of place. The framework that brands set for the representation of landscapes overall amounts to an exercise in calculated aesthetics, whereby the form and content of landscape images of various kinds is measured to achieve the greatest market differentiation and impact which technologies allow. The result of this calculated aesthetic system, with its taglines, saturated color, careful composition and magazine-format brevity, is a reduction in the complexity of landscape representations and a perpetuation of nature stereotypes.  相似文献   

17.
长江三角洲区域发展与人口,资源,环境   总被引:4,自引:0,他引:4  
历史时期,长江三角洲地区经济发展,具有与人口增长基本同步的三个发展时期。在此过程中,人口增长因素,在不同历史时期,对区域发展起着各具特色的作用。南北朝以来,人口增长过快而产生一系列人口、资源、环境失衡问题,其中某些如水域环境变化等,对当今区域经济的发展,仍然起着深刻的作用与影响。当今随着经济的纵深发展,在历史问题基础上,深化产生了许多新问题,使人口、资源、环境关系更为复杂。对此必须抓住人口增长这个主要方面,挖掘资源潜力,统一规划,加强管理,使自然-社会-经济系统的各个方面处于最佳协调状态,控制熵增,以求区域环境的久治长安、区域经济的持续增长。  相似文献   

18.
Currently, artisanal fisheries in fresh water reservoirs have been losing ground to commercial fish farming and a great deal of fishery resources are being threatened by human interventions, such as reservoir management and increasing net-cage aquaculture. This study aims to understand the impacts of environmental changes on fishery resources and analyse the migratory fish breeding season as a missing link for fishery management in the semi-arid area of the São Francisco River Basin. Among the 870 fishermen operating in the Pernambuco part of the Itaparica Reservoir, 10% were interviewed and affirmed that fish stocks have been compromised due to the closed fishing period’s incoherence, exotic species insertion, and changes to the river flow caused by reservoir construction and operation. A significant correlation was observed between the Reproductive Activity Index (RAI) and precipitation (p?=?0.745) as well as between the RAI and the river’s flow (p?=??0.909). This shows how important it is to consider both the semi-arid climate setting and reservoir operation in determining the closed period which should safeguard fish reproduction. Monitoring the fish reproduction period and research on the reproductive biology of native fish species is needed in the São Francisco River Basin’s different stretches in order to guarantee valuable fish stocks and fisheries maintenance. Integrated action between the fish resource users, civil society, and federal bodies/agencies is essential in order to mitigate impacts and improve fish production systems, not only in Brazil, but in other regions experiencing a similar scenario.  相似文献   

19.
The distribution of some heavy metals in three different organs of mullet, Liza abu, and catfish, Silurus triostegus, from Atatürk Dam Lake located on Euphrates (Turkey) was studied. Co and Mo concentrations were below limits of detection in all fish organs, whereas Ni was also below limits in organs of mullet. The metal accumulation in the liver and gill of L. abu and S. triostegus was found to be quite high in comparison with the muscle. In general, the concentrations are similar to those previously observed on other fish studied in Atatürk Dam Lake and lower than those determined in Tigris River. The analysed metals (Co, Cu, Fe, Mn, Mo, Ni and Zn) were found in fish muscle at mean concentrations under the permissible limits proposed by FAO.  相似文献   

20.
人口,资源,环境与发展系统研究的基本思路   总被引:1,自引:0,他引:1  
人口、资源、环境与发展问题相互关联,构成了一个复杂巨系统。应用系统科学的思想方法研究这个复杂巨系统,是当前最令人注目的重大学术领域。本文探讨了这一系统研究的范围框架、基本内容结构和研究方法,建立了针对我国实际问题的系统概念模型。这一概念模型首次把人口、资源、环境、经济、科技、教育、文化等基本要素组织在一个完整的社会核算体系中。  相似文献   

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