Poverty, environment and natural resource use: introduction to the special issue

A growing population and growing per capita consumption threaten the environment and the natural resource base. Where natural resources are at risk, the livelihoods of many are at risk as well. In May 2006 the Environmental Economics and Natural Resources Group of Wageningen University organized a conference on `Poverty, Environment and Natural Resource Use¿ with the aim of contributing to a better understanding of the links between poverty and the natural resource base. The state of the environment affects people's living conditions ¿ and poverty affects environmental quality. Environmental policies cannot be designed and natural resources cannot be managed without appropriate consideration of local people's reactions to those policies and management decisions

Costs and benefits of adapting to climate change at six meters below sea level

Climate change increases the vulnerability of low-lying coastal areas. Careful spatial planning can reduce this vulnerability. An assessment framework aimed at reducing vulnerability to climate change enables decision-makers to make better informed decisions about investments in adaptation to climate change through spatial planning. This paper presents and evaluates an approach to assess adaptation options, with the use of cost-benefit analysis

On the risk of extinction of a wild plant species through spillover of a biological control agent: analysis of an ecosystem compartment model

Invasive plant species can be controlled by introducing one or more of their natural enemies (herbivores) from their native range; however such introduction entails the risk that the introduced natural enemy will attack indigenous plant species in the area of introduction. The effect of spillover of a natural enemy from a managed ecosystem compartment (agriculture) in the area of introduction to a natural compartment (non-managed) in which an indigenous plant species is attacked by the introduced natural enemy, whereas another indigenous plant species, which competes with the first, is not attacked, has been studied. The combination of competition and herbivory may result in extinction of the attacked wild plant species. Using a modelling approach, the authors have determined model parameters that characterize the risk of extinction. The findings point to the importance of spillover and the relative attack rates (specificity) of introduced natural enemies with respect to target and non-target plant specie

Economic Modelling for water Quantity and Quality Management: A Welfare Program Approach

This paper presents an integrated economic model which is able to explicitly address both water quantity and quality. We use a welfare program to maximize social welfare subject to the economic and ecological constraints, where interactions, emissions and environmental impacts are incorporated. Such a welfare program can provide the marginal values of commodities and therefore can price water by means of shadow pricing. The optimal solution to a specified program provides the optimal response strategies, i.e. the efficient allocation of resources in the economy including water use and the efficient level of water quality. We illustrate the mechanism in a numerical example and show, as an example, how we can achieve efficiency by reserving water in the high season for times of high demand in the low season and by introducing price differentiation between the two season

Impacts of HIV/AIDS on Labor Allocation and Crop Diversity : do Stages of the Disease Matter?

This paper deals with the impact of HIV/AIDS on labor allocation and crop diversity. The study is based on an in-depth analysis of 4 case studies in Ethiopia. A novel element in the study is the emphasis on the distinction of various stages in which the disease affects families. Results show that impact on labor allocation very much depends on the various stages of the disease and which family member (or members) is affected. Also land tenure plays an important role, because of the options of having sharecropping contracts or opportunities for off-farm labour. This has implications for the intervention strategies in the various phases of the disease, both for men and women

A model-based assessment of adaptation options for Chianti wine production in Tuscany (Italy) underclimate change

This paper covers a comprehensive economic analysis of climate change adaptation options for a specific wine producing region, namely Tuscany. As temperature increases under climate change, rainfall patterns will be different, and Chianti wine production in Tuscany therefore needs to adapt in the near future. We address the adaptation challenges and identify grape yield and quality loss as the main impact of climate change on wine production. Relocation of vineyards uphill and introducing drought-resistant varieties are considered as adaptation measures. We appraise these adaptation measures using an optimization framework, where regional wine producers maximize income subject to economic constraints including the climate change impacts on wine productivity and quality. Our simulation shows quantitatively to what extent a higher degree of climate change impact demands a higher degree of adaptation. We find that a combination of the two measures provides a better strategy because it leads to higher economic efficiency. However, uncertainty regarding the efficiency of the new variety discourages the use of this new drought-resistant variety, whereas a higher efficiency would make this choice more favourable. Sensitivity analysis for time horizon and discount rate confirms the theory of investment under uncertainty, showing a shorter time horizon (or more frequent investment) provides the possibility to postpone the decision to implement adaptation measures due to the value of flexibility, while a higher discount rate leads to a later adaptation decision, because uncertainty creates a value of waiting for new information

The role of rainfed agriculture in securing food production in the Nile Basin

A better use of land and water resources will be necessary to meet the increasing demand for food in the Nile basin. Using a hydro-economic model along the storyline of three future political cooperation scenarios, we show that the future of food production in the Basin lies not in the expansion of intensively irrigated areas and the disputed reallocation of water, but in utilizing the vast forgotten potential of rainfed agriculture in the upstream interior, with supplemental irrigation where needed. Our results indicate that rainfed agriculture can cover more than 75% of the needed increase in food production by the year 2025. Many of the most suitable regions for rainfed agriculture in the Nile basin, however, have been destabilized by recent war and civil unrest. Stabilizing those regions and strengthening intra-basin cooperation via food trade seem to be better strategies than unilateral expansion of upstream irrigation, as the latter will reduce hydropower generation and relocate, rather than increase, food production