This chapter initially examines general relationships between agricultural activity and environmental change and the level of economic welfare. It then provides a brief account of the historical development of agriculture, focusing on its environmental and socio-economic consequences. The pivotal role of the commencement and evolution of agriculture in economic development is stressed. It is only as a result of agriculture that the current level of the world’s population can be sustained. For a considerable amount of time, the world’s population has exceeded that which can be sustained by hunting and gathering. A major challenge which agriculture faces in this century is how to increase its production to meet increasing demands for food due to global population growth and rising incomes, and how it can achieve this without causing significant environmental deterioration. Can this be achieved by sustainable agricultural intensification? This is one of the issues discussed. The likely impacts on the level of agricultural production of climate change and the adjustment issues facing agriculture as a result of climate change are major contemporary concerns. The modelling of these aspects is reviewed and some different perspectives are provided compared to those in the literature, for example, the perspective presented by Mendelsohn and Dinar. The desirability of different types of public policies for responding to the effects of climate change on agriculture is also discussed.
The Challenges We Face
Clement A. Tisdell
Clement A. Tisdell
Marine ecosystems are estimated to have a high economic value. The total value of these services and their existing value in various geographical locations are being threatened and altered by environmental changes due to rising atmospheric greenhouse gases, especially increases in CO2 contributions. This chapter begins by outlining the basic abiotic changes in marine ecosystem systems which are attributable ultimately to increasing concentrations of greenhouse gases in the atmosphere. These changes in turn have important impacts on marine biota. A case study of predictions about the impact of climate change and ocean acidification on the economic value of the Norwegian fisheries is reviewed. This reveals both economic and ecological challenges that need to be surmounted to obtain reliable estimates of this type. The changing economic value of coral reefs due to climate change is also investigated, and some important limitations of current economic estimates are found. It is noted that despite the loss and degradation of coral reefs, the economic value of remnant reefs can actually increase, although overall human well-being declines. The need to take account of opportunity costs when assessing the desirability of conserving coral reefs is raised. It is also important for the purpose of economic valuation to take into account the dynamics of changes in marine ecosystems subjected to environmental stressors, such as climate change. This aspect is considered. Economic policies for responding to alterations in marine ecosystems due to climate change are briefly discussed, and the relevance of economic and ecosystem resilience to this topic is investigated.