It is encouraging that, in the last decade or so, a substantial amount of work has addressed precisely these questions. The present paper draws on this body of research. It then discusses the primary policy approaches to the problem of environmental degradation. It does not attempt to cover the full range of social issues associated with all types of environmental degradation. Restrictions on vehicles and industrial activity during critical periods affect productivity, as does the effect of acid rain on forests and water bodies.
Wastes affect productivity through the pollution of groundwater resources.
Productivity losses on tropical soils are estimated to be in the range of 0.5-1.5 per cent of GNP, while secondary productivity losses are due to siltation of reservoirs, transportation channels and other hydrologic investments. Death and disease can result from the localized flooding caused by deforestation. Loss of sustainable logging potential and of erosion prevention, watershed stability and carbon sequestration provided by forests are among the productivity impacts of deforestation. Global warming may lead to a shift in vector-borne diseases and increase the risk of climatic natural disasters. Productivity impacts may include sea-rise damage to coastal investments, regional changes in agricultural productivity and disruption of the marine food chain.