This thesis consists of four self-contained papers, which are all related to important environmental and natural resource issues from a developing country perspective. Paper [I] concerns climate policy and addresses the potential welfare gains of introducing a technology transfer from the North (richer countries) to the South (poorer countries). The results largely depend on the environmental policy in the pre- transfer resource allocation and, in particular, whether or not the South abates its own emissions. Although the technology transfer is desirable from a “global social planners” point of view, it is shown that the incentives to use the transfer might be weak from the perspective of the North; at least if the South takes its own measures to reduce emissions. However, in a situation where the North is committed to emission reductions according to the Kyoto protocol, it is shown that there will clearly be incentives for the North to use the technology transfer in order to reach the Kyoto targets in a more cost efficient way. In paper [II], the likely effects of an environmental fiscal reform in Namibia are examined by means of a Computable General Equilibrium (CGE) model. The results show that the introduction of an environmental fiscal reform, where taxes on natural and environmental resources (fish rents, energy and water) are recycled to the economy in different ways might give rise to benefits in terms of GDP, employment and income distribution, in addition to the environmental impacts. While subsidizing unskilled labour would give the most favourable outcome in terms of real GDP and employment impacts, a decrease in food taxes might be a more interesting option if GDP, employment, income distribution and environmental impacts are considered in combination. In paper [III], the value of irrigation water used for different crop alternatives in the Hardap region in Southern Namibia is estimated. The study finds that all crop alternatives that farmers in the region currently choose among, will remain financially viable after the planned increases in user charges. However, if full cost recovery is to be achieved in the future, substantial changes in the agricultural production will most likely be necessary. The method is also extended in order to study the potential effects on total water demand if further increases in user charges are implemented. Paper [IV] studies the likely effects of exogenous international food and oil price shocks on the Namibian economy. This is particularly interesting in a country where the domestic consumption of corn and petroleum products is mainly imported, and where water scarcity represents one of the main constraints to agricultural expansion. The results show that the Namibian economy will be negatively affected from the food and oil price increases, and water scarcity will further limit the ability of the economy to adapt to international oil and food price increases.