|Area with high risk of water-induced soil
degradation: Africa (% of total land area)
Africa is at high risk from waterinduced
soil erosion, except for Northern Africa where low rainfall
keeps the risk extremely low. The area under risk grows considerably
in all scenarios as a result of intensifying agriculture,
combined with adverse consequences of climatic change.
Source: IMAGE 2.2 (see technical
|Percentage of 2002 cropland severely degraded
by 2032: Africa
Bars represent the percentage of 2002
cropland that has become so degraded by 2032 that it is of
little value for production.
Source: PoleStar (see technical
|Key to charts
Growing populations, economic development and changes in climate all
contribute to increasing the risk of land degradation in much of Africa
(see chart on the right). Stronger economic growth in the region under
Policy First and Sustainability First conditions, implies that the risk
of land degradation is higher than in Markets First. The sharper increase
apparent in Security First reflects the greater area of land brought into
agriculture under this scenario in order to meet the demands of the still
rapidly increasing population. It also indicates relative inability to
fall back on food imports and diminishing rates of return from improving
The translation from risk to actual degradation may be mediated in a
number of ways, however (see chart on the right). Cropland has been extensively
degraded in the past in Africa due to salinization, wind and water erosion.
In the worlds of Policy First and Sustainability First, easier access
to support services helps farmers to manage soils better, curtailing problems
like compaction, erosion and salinization. Policies based on integrated
land use management, including more stable land tenure systems, become
commonplace in most parts of the region. Technological advances prompted
by a combination of government incentives and private sector innovations,
help improve productivity of degraded land. The slightly higher level
of degradation in Policy First versus Sustainability First reflects slight
differences in demand for food - particularly animal products. At the
other end of the spectrum, in a Security First scenario, a combination
of inequitable land distribution, poor farming methods, unfavourable land
tenure systems and inefficient irrigation systems leads to declining productivity
of grazing and agricultural lands. Better conditions are, however, maintained
in the protected areas serving the elite. The concentration of large numbers
of people in fragile areas beyond the control of the land-owning elite
further contributes to the degradation of land and severe soil erosion.
Similar problems arise in a Markets First situation as better quality
agricultural land is taken over for commodity and cash crop production.
The environment suffers as a result as soils are 'mined' and the use of
fertilizers and pesticides becomes more extensive. Water resources and
aquatic ecosystems are particularly damaged.