Economic and Social Impacts Assessment of DLDD. Chapter 2
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There is a widespread consensus that the pressing issues of Desertification, Land Degradation and Drought (DLDD) are inadequately addressed in today’s political agenda at the global, regional and national levels. It is therefore of vital importance to raise awareness on the issues, not only on the negative impacts of DLDD in terms of socio - economic development, but also on the opportunities that they may create to help to guide current and future land management practices to be more sustainable and resilient Understanding and evaluating the economic and social costs and benefits associated with DLDD is essential to developing cost - effective policies and strategies for addressing DLDD and in raising this awareness. This paper discusses the e conomic and social impacts of DLDD based on the overall framework provided by the S cientific A dvisory Committee (SAC). L ittle res earch has been published in peer - reviewed academic journals on the economics of desertification, or of land degradation in general. This severely constrains the scientific knowledge which this working group can synthesize and evaluate for the Committee on Science and Technology (CST) . One reason for the gap is that formal economic modelling of land degradation only began in the 1980s. Another is that the volume of economic research in this field has not expanded greatly since the early 1990s. Direct economic costs are incurred through reductions in income obtained by land users as a result of the lower productivity of land resulting from desertification. These 'on - site' costs are experienced either by the land user who degraded the land or anot her user who uses the site subsequently. However , estimates vary widely and are very inaccurate. For example, four estimates of direct costs as a proportion of Gross Domestic Product (GDP) in single countries in the 1980s were: 0.4% of GDP in the USA; 2% o f GDP in India; 9% of GDP in Burkina Faso; and 0.9 - 12.5% in Mali. Large differences are also found between the direct costs estimated in different studies for the same country, e.g. India and China. Estimate variation and inaccuracy can be linked to the la ck of reliable biophysical measurements of the extent and rate of change o f desertification; the use of different economic estimation methods; the embryonic nature of economic research in this field; and isolation from estimates of the benefits of actions that cause degradation and are central to decision - making and its appraisal. Indirect economic costs are incurred throug h off - site impacts that can be some distance from the land use that is the source of degradation, and so are generally suffered by peop le other than those who cause degradation. For example, the erosion of soil by water and wind leads to the siltation of rivers, reservoirs and irrigation canals which reduces their effectiveness and exacerbates flooding. E xcessive or inappropriate use of w ater results in salinity and alkalinity. Estimates of indirect costs are less common than those for direct costs, and most indirect costs are still not estimated because of lack of data . The annual indirect costs of soil erosion in the USA have been estima ted as $17 billion, compared with direct costs of $27 billion, raising total costs of soil erosion to 0.7% of GDP . In China, sand and dust storms linked to soil erosion have resulted in indirect costs due to airline delays and impacts on human health. The range and inaccuracy of estimates of indirect costs is explained in a similar way to those for direct costs, with the additional complications that market prices are lacking for many of these impacts and impact profiles vary from country to country.