Land Degradation (Hansard, 19 April 2004)

Mr. Gareth Thomas

Comparative global land degradation data are not available for the years requested. They are available for 1992 when the most recent global assessment of land degradation was made, and I have provided these as follows.

Land degradation takes a number of forms, including depletion of soil nutrients, salinisation, soil erosion, vegetative degradation, and deforestation. All of these types of degradation cause a decline in the productivity of the land, reducing potential yields and posing a potential threat to the rural livelihoods of poor people in developing countries.

Existing estimates of the current global extent and severity of the problem of land degradation should be considered indicative at best: land degradation is something that cannot be easily monitored and measured. Responding to the need for a global overview of land degradation, the Global Assessment of Human-induced Soil Degradation (GLASOD), published in 1992, became the first comprehensive soil degradation 389W overview on a world scale. Soil degradation is considered to be a good indicator for measuring land degradation.

GLASOD is limited, however, and the need for more objective, qualitative approaches, using nationally-based data rather than global or regional figures, is widely recognised. New international initiatives are underway to develop national data acquisition on land degradation, using GIS (Geographic Information Systems), remote sensing and local assessments.

Based on the results of the 1992 Global Assessment, the percentage of land area pet region affected by human-induced soil degradation is as follows:

(a) Africa: 16.6 per cent. of total land surface
(b) Asia: 17.6 per cent. of total land surface
(c) South America: 13.7 per cent. of total land surface
(d) Europe: 23 per cent. of total land surface
(e) North America: 5 per cent. of total land surface.