执行国际协定的限制因素:博茨瓦纳执行《蒙特利尔议定书》的情况

本文分析了在博茨瓦纳有效执行<蒙特利尔议定书>中遇到的困难;并就在发展中国家执行国际协定问题时如何向决策者提出建议提供了一个总的认识.对臭氧耗损物质(ODSs)的正式和非正式用户进行的问卷调查表明:所散发的有关ODSs的信息,对于用户们选择制冷气体几乎没有什么影响,而且这个信息偏向有利于ODSs的正式用户.因此,ODS使用数量的年统计资料可能估计偏低.困难在于,要在短期内从老技术转向新技术,成本较高.回收废气和处理废旧硬件设备的基础设施缺乏或不足.这些问题的解决需要一个全面的政策,它能满足所有ODSs用户的要求;还需要把经济发展与环境保护结合起来进行考虑.     

Constraints to implementing international agreements: the case of the Montreal Protocol in Botswana

This study addresses the difficulties surrounding effective implementation of the Montreal Protocol in Botswana and provides a general understanding of how best we might advise policy makers when implementing international agreements in the developing world. A questionnaire survey administered to both the formal and informal users of Ozone Depleting Substances (ODSs) revealed that disseminated information on ODSs has little effect on choices that users make about refrigerant gases and this information is skewed in favor of the conventional users of ODSs. As a result, annual statistics of ODS use are probably underestimated. Difficulties exist in changing from old to new technologies in the short term due to high costs associated with the change over. The infrastructure to recover gases and to dispose of unusable hardware is absent or inadequate. Solutions to these difficulties include a comprehensive policy that caters for all users of ODSs and the integration of economic and environmental aspirations.     

Climate- and human-induced woody vegetation changes in Botswana and their implications for human adaptation

For purposes of suggesting adaptive and policy options regarding the sustained use of forestry resources in Botswana, an analysis of the whole countrywide satellite data (showing the mean present distribution of vegetation in terms of species abundance and over all density) and the projection of vegetation cover changes using a simulation approach under different climatic scenarios were undertaken. The analysis revealed that changes in vegetation cover types due to human and natural causes have taken place since the first vegetation map was produced in 1971. In the southwest, the changes appear to be more towards an increasing prevalence of thorn trees; in the eastern part of the country where widespread bush encroachment is taking place, the higher population density suggests more human induced (agrarian-degradation) effects, while in the sparsely settled central Kalahari region, changes from tree savanna to shrubs may be indicative of the possible influence of climate with the associated effects of fires and local adaptations. Projection of future vegetation changes to about 2050 indicates degeneration of the major vegetation types due to the expected drying. Based on the projected changes in vegetation, current adaptive and policy arrangements are not adequate and as such a shift from the traditional adaptive approaches to community-based types is suggested. Defining forestry management units and adopting different management plans for the main vegetation stands that are found in Botswana are the major policy options.