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(continued...)
In the household sector, fuelwood accounts for 97% of all energy consumed (Chidumayo,
1997). Although natural stocks of wood may be high, wood resources available
to the majority of the rural population are very low in many areas. Brickmaking
and tobacco and tea curing are major wood uses. In Zimbabwe, wood used for brickmaking
is said to equal that used for cooking in rural areas (Bradley and Dewees, 1993);
tobacco estates in Malawi account for 21% of total fuelwood consumption (Moyo
et al., 1993). In Botswana, the fencing of fields to keep out livestock consumes
1.5 times more wood than is used for cooking in farming households (Tietema
et al., 1991). Indigenous miombo and other woodlands in sub-Saharan Africa contribute
significantly to the firewood harvested for consumption and conversion to charcoal.
Stands are left to recover, with minimal active management. The ability of users
to purchase alternative forms of energy (gas or electricity), as well as charcoal,
depends on the economics of each family. Therefore, poor people (with limited
buying power) are most vulnerable to reductions in fuelwood supply. Increasing
populations also are contributing to depletion of resources. In relatively dense
woodland areas, where population density is low, there usually is enough deadwood
that can be collected and used for fuelwood. Increasing incidence of drought,
however, leads to increased fire frequency-which, in turn, reduces deadwood
material in woodlands. If current natural resource management systems are not
changed, Africa could run the risk of depleting its forest resources used as
biomass energy at a rate faster than the rate of population growth. The paucity
of data on biomass depletion and regeneration rates makes meaningful assessment
difficult and compounds the problems of possible reduced precipitation and subsequent
lower regeneration rates by making it difficult to identify appropriate response
options. There already are indications of a negative supply balance (e.g., extensive
household utilization of agricultural and animal wastes for energy).
In 1992, Africa's electricity output was 312,000 GWh; thermal power provided
78% and hydroelectricity 19%, with a small amount (3%) from nuclear sources
in South Africa (ADB AEP, 1996). Thermal power plants require huge volumes of
water in their cooling systems; in a situation of reduced rainfall, loss of
cooling-water resources will not only reduce generation capacity but also retard
construction of new plants. It may be reasonably expected, therefore, that exploitation
of the continent's massive coal reserves in areas with such resources would
be inhibited by both the anti-coal lobby and shortages of cooling water. In
the past (e.g., during the drought of 1991-92), declines in precipitation led
to a significant loss of total hydropower energy, including losses of as much
as 30% from the Kariba Dam (which supplies power for Zambia and Zimbabwe). It
has been suggested that future hydropwer output could could be affected by climate
change. Salewicz (1995) investigated the vulnerability of the Zambezi basin
to climate change. He noted that 75% of the lower Zambezi waters flow into Kariba.
Under climate change scenarios, this area is projected to experience increased
rainfall and runoff into Lake Kariba. Although there may be shifts in the seasonal
reliability of given discharges for the Lower Zambezi, it is possible that hydropower
generation capacity would be adversely affected. Similar impacts could occur
on the Congo, Nile, and Niger river hydropower systems, resulting in critical
electricity supply shortfalls throughout the continent. In addition, the continent's
massive hydroelectric potential of 150,000 GWh/yr would be significantly curtailed.
Such a situation would lead to the introduction of major changes in fuel supply
strategies in most countries. A case has been made for developing micro- and
small-scale hydropower plants in Africa to overcome the cost of large-scale
generation systems. This type of plant will require a defined minimum level
of runoff. Reductions in precipitation could significantly reduce the number
of viable sites for such micro-hydro installations.
2.3.5.3. Industry
Changes in future climate should be actively considered in developing a sustainable
industrial development path for Africa. Vulnerability in African industry may
relate more to the inhibiting effects of climate change on industrial expansion
than to its effects on existing industrial installations and investments. The
most serious impacts of climate change on this sector would be related to loss
of competitiveness associated with increased costs of production resulting from
changes or retrofitting of plants for cleaner production. Reduced surface-water
supplies would lead to extended use of groundwater sources-which, in most cases,
have to be treated on site to achieve desired water-quality standards for specific
industrial applications. Other major effects will result from a lack of water
for industrial processes and increased costs of cooling for temperature-controlled
processes and storage; Africa's industry has a large number of agro-industrial
operations that need large amounts of water.
Besides these direct effects, there will be indirect effects, such as rising
water costs; in cases of severe and recurrent water shortages, this factor could
lead to relocation of industrial plants. Electricity shortages, due to a drop
in the water level which causes a decline in hydropower, also will affect industry-particularly
the steel sector (including iron and steel), ferro-chrome production, cement
production, textiles, and aluminum production. These industries are among some
of the most advanced on the continent, but they are highly dependent on constant
electricity supplies. Although there are no data to indicate the level of water
shortages that may result from a decline in precipitation, it is obvious that
water shortages that affect concentrated urban settlements also will have a
debilitating effect on industrial production. Water demand in many states in
southern and northern Africa already has exceeded or is expected to exceed water
supply soon.
Although detailed assessments of the impact of sea-level rise on coastal industries
have been made for Asia and other regions, little information is available for
Africa. It can be assumed, however, that most of the impacts that would ensue
in other coastal zones would apply equally in Africa. Most impacts would be
related to relocation of industries. The extent of these impacts could not be
assessed in any detail without a more complete assessment of coastal zone industrial
locations.
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