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1.
Environment, Development and Sustainability - Globally, traditional knowledge is at stake, notwithstanding intentions recorded in international policy conventions. Egypt has accepted and ratified...  相似文献   
2.
The use of assimilation tools for satellite validation requires true estimates of the accuracy of the reference data. Since its inception, the Network for Detection of Stratospheric Change (NDSC) has provided systematic lidar measurements of ozone and temperature at several places around the world that are well adapted for satellite validations. Regular exercises have been organised to ensure the data quality at each individual site. These exercises can be separated into three categories: large scale intercomparisons using multiple instruments, including a mobile lidar; using satellite observations as a geographic transfer standards to compare measurements at different sites; and comparative investigations of the analysis software. NDSC is a research network, so each system has its own history, design, and analysis, and has participated differently in validation campaigns. There are still some technological differences that may explain different accuracies. However, the comparison campaigns performed over the last decade have always proved to be very helpful in improving the measurements. To date, more efforts have been devoted to characterising ozone measurements than to temperature observations. The synthesis of the published works shows that the network can potentially be considered as homogeneous within +/-2% between 20-35 km for ozone and +/-1 K between 35-60 km for temperature. Outside this altitude range, larger biases are reported and more efforts are required. In the lower stratosphere, Raman channels seem to improve comparisons but such capabilities were not systematically compared. At the top of the profiles, more investigations on analysis methodologies are still probably needed. SAGE II and GOMOS appear to be excellent tools for future ozone lidar validations but need to be better coordinated and take more advantage of assimilation tools. Also, temperature validations face major difficulties caused by atmospheric tides and therefore require intercomparisons with the mobile systems, at all sites.  相似文献   
3.
In 1988 the Toronto World Conference on the Changing Atmosphere called for a reduction of CO2 emissions of the industrialized countries by approximately 20% by the year 2005 as compared with 1988. A stabilization of CO2 concentrations would require an eventual emissions reduction of more than 50% of present levels. Model runs were performed with the Dutch Integrated Model for the Assessment of the Greenhouse Effect (IMAGE) to put these figures into perspective. It was found that the suggested emissions reduction levels could indeed be adequate to prevent global temperature change from moving beyond past climate experience. However, this would only be the case when these reduced levels of emissions were achieved at a global scale and maximum emission control for the other greenhouse gases was implemented. A delayed response analysis shows that the policies of the coming decades are crucial for the eventual control of the greenhouse effect.  相似文献   
4.
Forest fires and adaptation options in Europe   总被引:1,自引:0,他引:1  
This paper presents a quantitative assessment of adaptation options in the context of forest fires in Europe under projected climate change. A standalone fire model (SFM) based on a state-of-the-art large-scale forest fire modelling algorithm is used to explore fuel removal through prescribed burnings and improved fire suppression as adaptation options. The climate change projections are provided by three climate models reflecting the SRES A2 scenario. The SFM’s modelled burned areas for selected test countries in Europe show satisfying agreement with observed data coming from two different sources (European Forest Fire Information System and Global Fire Emissions Database). Our estimation of the potential increase in burned areas in Europe under “no adaptation” scenario is about 200 % by 2090 (compared with 2000–2008). The application of prescribed burnings has the potential to keep that increase below 50 %. Improvements in fire suppression might reduce this impact even further, e.g. boosting the probability of putting out a fire within a day by 10 % would result in about a 30 % decrease in annual burned areas. By taking more adaptation options into consideration, such as using agricultural fields as fire breaks, behavioural changes, and long-term options, burned areas can be potentially reduced further than projected in our analysis.  相似文献   
5.
6.
The Wild Animal as a Research Animal   总被引:1,自引:0,他引:1  
Most discussions on animal experimentation refer to domesticated animals and regulations are tailored to this class of animals. However, wild animals are also used for research, e.g., in biological field research that is often directed to fundamental ecological-evolutionary questions or to conservation goals. There are several differences between domesticated and wild animals that are relevant for evaluation of the acceptability of animal experiments. Biological features of wild animals are often more critical as compared with domesticated animals because of their survival effects. An important issue is what is called here “natural suffering”: the suffering from natural circumstances. Should this type of suffering be taken into account when suffering from experimentation is evaluated? As an answer, it is suggested that ``natural functioning'' should be considered as an additional standard in the evaluation of wild animal experimentation. Finally, two topics related to the ecological context are considered. Firstly, the often inevitable involvement of non-research animals in wild animal experimentation, and secondly, the eco-centric approach to nature conservation. According to the latter position, animals are subordinated to ecosystems. All these aspects make the evaluation of wild animal experiments much more complex than experiments with domesticated animals. Preliminary scores are proposed to deal with these aspects. It is argued that this should not lead to a more complex governmental regulation, since an effective maintenance and control are hard to realize and one may loose the cooperation of researchers themselves. In addition, non-governmental professional organizations such as research societies and funding organizations play a pivotal role.  相似文献   
7.
Land-use emissions of greenhouse gases make up over one-third of current total anthropogenic emissions of greenhouse gases and about three-quarters of the total anthropogenic emissions of CH4 and N2O. Considering their contribution to global emissions, it is important to understand their future trends in order to anticipate and mitigate climate change. This paper reviews published scenarios of major categories of these emissions with the aim to provide background information for the development of new scenarios. These categories include CO2 from deforestation, CH4 from rice cultivation, CH4 from enteric fermentation of cattle, and N2O from fertilizer application. Base year estimates of all these categories varied greatly from reference to reference, and hence emissions of all scenarios were normalized relative to their 1990 value before being compared to one another. The range of published scenarios of CO2 emissions from deforestation is widest around the middle of the 21st century and then all scenarios converge to low values towards 2100. By contrast, the different scenarios of CH4 and N2O diverge with time, showing their widest range in 2100. Global emissions of CH4 from rice cultivation vary by a factor of three in 2100 and N2O from fertilized soils by a factor of 2.3. Emissions of CH4 from enteric fermentation of animals have the smallest range (factor of 2.0). The typical long-range trends of land-use emission scenarios vary greatly from region to region - they stabilize in industrialized regions after a few decades, but tend to stabilize later in developing regions or continue to grow throughout the 21st century. To improve the realism of the estimates of future trends of land-use emissions, it is especially important to improve the estimation of the future extent of agricultural land and the rate of deforestation, while taking into account significant driving forces such as the demand for agricultural commodities and crop yields.  相似文献   
8.
Oxygen and carbon stable isotope profiles were constructed for two species of large subtropical gastropods of the family Fasciolariidae—Triplofusus giganteus and Fasciolaria tulipa—from the Florida Keys and the Bahamas, to evaluate their life history and to assess their potential as paleoenvironmental proxies. Oxygen isotope profiles revealed T. giganteus and F. tulipa grew their shells for 6 and 3 years, respectively. Both mollusks show faster growth rates during the first half of their lifespan. Mean annual temperatures (MAT) derived from oxygen isotopes for T. giganteus were 26.5 °C and for F. tulipa were 26.7 °C, both matching instrumental MATs of 26.7 and 26.5 °C for the Florida Keys. Both shells, however, failed to record entire mean annual temperature ranges (MART). Fasciolaria tulipa yielded a calculated MART of 5.6 °C compared with a measured MART of 9.3 °C, and T. giganteus showed a calculated MART of 6.9 °C compared with a measured MART of 9.4 °C. Carbon isotopes of T. giganteus were ambiguous and reveal no significant relationships with trends in nutrient concentrations (N and P), dissolved oxygen, and dissolved organic carbon, although they did exhibit more negative values concomitant with landfall of Hurricane Irene and trended to increasing values with ontogeny that could reflect migration. Carbon isotopes in F. tulipa were lower during winters, possibly reflecting seasonal upwelling or seagrass-mediated carbon cycling.  相似文献   
9.
We analyzed 30 protein-coding loci of four southern African black rhinoceros populations in order to calculate fixation indices and genetic distances for the different populations. We concluded that one of these populations is of the subspecies Diceros bicornis bicornis and the other three of Diceros bicornis minor. No evidence of inbreeding within populations was found. F- statistics revealed significant differentiation between populations. Small genetic distances found among the four populations reveal that they are conspecific, and no evidence was found to support the claim that the populations belong to discrete subspecies. Rather, an east-west cline in genetic characteristics appears to exist with G6pd and HB-2 alleles peculiar to western populations and Es-2 and GP-3 alleles peculiar to eastern populations.  相似文献   
10.
The identity of compounds responsible for estrogenic and dioxin-like activities in sediment from the harbour of the small town Zierikzee in Zeeland, The Netherlands, was investigated using a bioassay directed fractionation approach with the in vitro estrogen and dioxin responsive reporter gene assays ER- and DR-CALUX. For identification of compounds exhibiting activity in the bioassays, either one or two-dimensional GC in combination with quadrupole (MSD), ion trap (ITD) or time-of-flight mass spectrometric detection (ToF-MS) was used, depending on the biological and chemical characteristics and the complexity of the fractions. The natural estrogenic hormone 17-β-estradiol and its metabolite estrone were identified with GC–ITD as the main contributors to the estrogenic activity. After successive rounds of fractionation, the dioxin-like activity could be explained by the presence of various polycyclic aromatic hydrocarbons identified with GC–MSD and two-dimensional comprehensive GC × GC–ToF-MS. Some estrogenic activity of a relatively non-polar nature remained unidentified.  相似文献   
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