Environmental policy making is a challenging task. Often the scope of an issue is not fully comprehended, and its future impact is even less well understood. Global warming is one of these environmental issues. The issue is made more complex because, first, there is a question of whether it is a problem at all and, second, unilateral policy making by one nation may not be sufficient or even significant to tackle the problem globally. This article outlines the scientific factors that contribute to global warming and discusses the uncertainties involved. The authors then discuss the ramifications of taking action (policy making) and failing to act (doing nothing) against the background of global warming, greenhouse gases, and cost-benefit analysis. The article concludes by reporting the results of a multidisciplinary panel of experts composed of scientists, economists, and policy analysts who commented on various policy options. 相似文献
The study has analysed the effects of various factors on hydroelectric power generation potential to include climate change/variability,
water demand, and installation of proposed hydroelectric power schemes in the Zambezi River Basin. An assessment of historical
(1970–2000) power potential in relation to climate change/variability at existing hydro electric power schemes(Cahora Bassa,
Kariba, Kafue Gorge and Itezhi-Tezhi) in the Zambezi River Basin was conducted. The correlation of hydroelectric power potential
with climate change/variability aimed at observing the link and extent of influence of the latter on the former was investigated.
In order to predict the future outlook of hydro electric power potential, General Circulation Models (GCM) were used to generate
projected precipitation. The monthly simulated precipitation was extracted from the GCM for every sub basin and used to compute
future precipitation. Further, future water demand in the sub basins of the Zambezi River Basin were estimated based on the
respective population growth rate in each sub basin. Subsequently, water balance model, with projected precipitation and water
demand input was used to determine projected run-offs of sub basins of the Zambezi River Basin. .Based on the projected run-offs
of sub basins, reservoir storage capacities at existing hydro electric power schemes were estimated. The baseline assessment
revealed a strong relationship between hydroelectric power potential and climate change/variability. The study also revealed
that the main climate and other risks associated with current and future hydro electric power generation include projected
dry years, floods and increasing water demand. The results indicate that the hydroelectric power potential has a tendency
towards gradual reduction in its potential in all existing and proposed hydroelectric power schemes owing to climate change
and increasing water demand. 相似文献
INTRODUCTION: Through observations this study sought to examine the effects of road familiarity on driving performance. METHOD: Severe and minor traffic violations, dangerous behaviors, and speeding were assessed in well known and in less familiar locations. RESULTS: As compared to less known locations, drivers in well known locations performed more severe and minor violations, more dangerous behaviors, and they drove above the speed limit more often. DISCUSSION: The results are discussed in the context of Theory of Risk Homeostasis (later re-labeled as Target Risk Theory), the psychological effect of familiarity on driving performance, and the phenomenon of automatic driving. Presenting the risk of driving in familiar locations would assist to elevate safe driving. 相似文献
Plants of Vigna radiata L. var. PDM 54 (mung bean) were grown in soil amended with different amounts (10 and 25%) of fly ash (FA). Although total
metal content increased with increasing FA amendment, DTPA-extractable metals were higher for 10% FA. Accumulation of metals
by the plants increased with increasing FA amendment and was greater in shoots than in roots (except for Mn and Cu) and seeds
(except Mn). The total daily intake (TDI) of all the tested metals in seeds was within the recommended dietary allowance (RDA)/provisional
tolerable daily intake (PTDI) for adults, except for Cd, which was higher than recommended values. Principal-components analysis
(PCA) based on studies of physicochemical properties, DTPA-extractable metals, and metal accumulation in the different parts
of V. radiata showed that physicochemical properties such as cation-exchange capacity, organic carbon, and organic matter had significant
positive effects on accumulation of Cd, Co, Ni, and Pb by the plant, whereas EC had a significant negative effect. Although
addition of fly ash (10%) initially increased the rate of growth, toxic symptoms were observed for 25% FA. Results from analysis
of antioxidants (carotenoids, ascorbic acid, non-protein thiol, and free proline) revealed that these increased more in plants
grown in 10% FA than in those grown in garden soil. Cysteine and malondialdehyde (MDA) content increased with increasing FA
amendment. PCA also showed that all the antioxidants studied behaved similarly except cysteine, for which there was a close
relationship with MDA content. Thus, the results obtained during this study revealed that V. radiata L. var. PDM 54 may be grown in 10% FA and/or contaminated agricultural soil. 相似文献
Thyroid dysfunction during pregnancy has been shown to be associated with adverse pregnancy outcomes. Consequently, this study was undertaken to assess the thyroid health of the pregnant females in the United States. Publically available data from National Health and Nutrition Examination Survey for the cycles 1999–2002 and 2007–2012 were analyzed for this purpose. Over 22% (SE: 5.7%) of the pregnant females based on the unweighted data in their first trimester had higher than the recommended levels of thyroid-stimulating hormone (TSH) or 2.5 mIU/L. Free triiodothyronine (FT3) and free thyroxine (FT4) levels decreased over pregnancy trimesters. Based on unweighted data, about 6% (SE: 2.6%) pregnant females were positive for thyroglobulin antibodies and 34.9% (SE: 5.2%) pregnant females were positive for thyroid peroxidase antibodies. Over 55% (SE: 3.5%) pregnant females based on the unweighted data were iodine deficient. As many as 41% (SE: 3%) first trimester pregnant females having TSH > 2.5 mIU/L is of concern. Future research should concentrate on developing educational and other materials that can advise pregnant females during their prenatal care and other appointments about the adverse effects of high TSH levels and what they can do to keep their TSH levels within the recommended levels. 相似文献
Shoreline is one of the rapidly changing linear features of the coastal zone which is dynamic in nature. The issue of shoreline changes due to sea level rise over the next century has increasingly become a major social, economic and environmental concern to a large number of countries along the coast, where it poses a serious problem to the environment and human settlements. As a consequence, some coastal scientists have advocated analyzing and predicting coastal changes on a more local scale. The present study demonstrates the potential of remote sensing, geospatial and statistical techniques for monitoring the shoreline changes and sea level rise along Digha coast, the eastern India. In the present study, multi-resolution and multi temporal satellite images of Landsat have been utilized to demarcate shoreline positions during 1972, 1980, 1990, 2000, and 2010. The statistical techniques, linear regression, end-point rate and regression coefficient (R2) have been used to find out the shoreline change rates and sea level change during the periods of 1972–2010. Monthly and annual mean sea level data for three nearby station viz., Haldia, Paradip and Gangra from 1972 to 2006 have been used to this study. Finally, an attempt has been made to find out interactive relationship between the sea level rise and shoreline change of the study area. The results of the present study show that combined use of satellite imagery, sea level data and statistical methods can be a reliable method in correlating shoreline changes with sea level rise. 相似文献
Total mass transfers of heavy metal in dissolved and particulate form has been determined in the downstream section of river
Hindon, an important tributary of river Yamuna (India). The contribution of different point sources to the river Hindon has
also been assessed. The river Kali has the largest contribution to the river Hindon. The highest metal loads were related
to the highest flow of the river and thereby increased both by surface runoff and sediment resuspension. The contribution
of monsoon months to the total transported load was also calculated and it was observed that monsoon months contributes more
than 40% of total loading annually for all the metals. The metal fluxes from the river Hindon were compared with other rivers
of Indian sub-continent. 相似文献
In the presented work, the effect of crosslinker geometry on the properties of PVA is reported. The aliphatic (suberic) and aromatic (terephthalic) dicarboxylic acids are used as crosslinker molecules. On the basis of tensile test and thermal properties, it is observed that crosslinking of PVA by suberic acid is more effective than terephthalic acid. The maximum strength measured in crosslinked samples is 32.5 MPa for suberic acid crosslinked PVA which is higher than that of neat PVA (22.6 MPa). Swelling study shows that 8 h crosslinked terephthalic acid (35% w/w) samples have a minimum of 5.4% of water uptake compared to neat PVA, which dissolves readily in water. DTGA shows that the decomposition temperature of crosslinked PVA is 345?°C while neat PVA has a decomposition temperature of 315?°C. FTIR spectroscopy confirms the formation of crosslink ester bond in crosslinked PVA. The crosslinked samples kept for bio-degradation show maximum degradation in terephthalic acid (15% w/w) crosslinked PVA. 相似文献
Environmental occurrence of CECs poses a great threat to both aquatic life and human health. The aim of this study was to optimize and validate SPE/LC-(ESI)MS-MS method for simultaneous quantitative monitoring of two sub-classes of CECs (pharmaceuticals and hormones) and to estimate the concentrations of select CECs in environmental water samples. For all the tested analytes, recoveries in laboratory reagent water were greater than 81%. Average percent (relative standard deviation) RSD of the analytes in recovery, repeatability, and reproducibility experiments were ≤?10%. Determination coefficients (r2) of primidone, diclofenac, testosterone, and progesterone were estimated to be 0.9979, 0.9972, 0.9968, and 0.9962, respectively. Limits of detection (LOD) for primidone, diclofenac, testosterone, and progesterone were 4.63 ng/L, 5.36 ng/L, 0.55 ng/L, and 0.88 ng/L, respectively. Limits of quantification (LOQ) for primidone, diclofenac, testosterone, and progesterone were 14.72 ng/L, 17.06 ng/L, 1.766 ng/L, and 2.813 ng/L, respectively. Average recoveries in environmental water and wastewater samples were greater than 74% and RSD were ≤?7%. Trace levels (68.33–125.70 ng/L) of primidone were detected in four environmental water samples, whereas diclofenac was not detected in any of the tested sample. Trace levels of progesterone were observed in two environmental samples (16.64 –203.73 ng/L), whereas testosterone was detected in STP inlet sample (178.16 ng/L). 相似文献
We examine the dynamics and spatial determinants of land change in India by integrating decadal land cover maps (1985–1995–2005) from a wall-to-wall analysis of Landsat images with spatiotemporal socioeconomic database for ~630,000 villages in India. We reinforce our results through collective evidence from synthesis of 102 case studies that incorporate field knowledge of the causes of land change in India. We focus on cropland–fallow land conversions, and forest area changes (excludes non-forest tree categories including commercial plantations). We show that cropland to fallow conversions are prominently associated with lack of irrigation and capital, male agricultural labor shortage, and fragmentation of land holdings. We find gross forest loss is substantial and increased from ~23,810 km2 (1985–1995) to ~25,770 km2 (1995–2005). The gross forest gain also increased from ~6000 km2 (1985–1995) to ~7440 km2 (1995–2005). Overall, India experienced a net decline in forest by ~18,000 km2 (gross loss–gross gain) consistently during both decades. We show that the major source of forest loss was cropland expansion in areas of low cropland productivity (due to soil degradation and lack of irrigation), followed by industrial development and mining/quarrying activities, and excessive economic dependence of villages on forest resources.