|Boiling Point No. 44 - Linking Household Energy with other Development Objectives (ITDG - ITDG, 2000, 44 p.)|
by Mr Joe Obueh, Project Director, Green Earth Project, Centre For Household Energy and the Environment (Ceheen), PO Box 1430, Agbor, Delta State, Nigeria (email@example.com).
Le coologique de l'accroissement de la dndance a la biomasse en tant que combustible domestique en milieu rural au Niga
La consommation de la biomasse rgie au Nigeria tend a croe du fait de l'inflation des prix des produits poliers. La drestation est un probl majeur d'accroissement de la population et a consommation de la biomasse rgie. La sur-exploitation de la fora conduit a dadation des terres, la perte de fertilites sols, la rction de la faune et une pollinisation des arbres moins importante, A l'elle mondiale, la diminution des surfaces forestis signifie la rction du gaz carbonique absorbartir de l'atmosph.
In Nigeria biomass fuels now meet about 80% of domestic energy requirements. This is because the country is experiencing its worst energy crisis in its economic history, which has raised the prices of petroleum products such as kerosene and gas above the purchasing power of most consumers, especially the rural poor, who make up 70% of Nigeria's teeming population.
Forest biomass has remained the commonest source of household energy; in 1992 alone, fuelwood and charcoal production were estimated at 55 million tonnes. More than half of the 9.6 million hectares of rain forest belt in the south of Nigeria has been used to meet the demand for fuelwood in rural and urban neighbourhoods. In villages in the grassland areas of the northern part of the country that boast of about 23% of pastureland, people rely on dung as an alternative source of energy.
Recent studies have indicated that non-sustainable logging for timber, expansion of city limits for urban developments and forest fires have made one-third of Nigeria's estimated 9.6 million hectares of forest cover vulnerable to deforestation. Continuous exploitation for fuelwood contributes greatly to further degradation and eventual deforestation of the forests.
Studies by the Federal Environmental Protection Agency (FEPA) indicate that although Nigeria banned all timber exports in 1976, deforestation from fuelwood extraction remains one of Nigeria's top three environmental problems, which directly affects about 50 million Nigerians mostly through declining fuelwood supplies (FEPA, 1992).
World-wide, fuelwood collection may not be responsible for major deforestation as dry fuel-wood is mostly being collected. However in Nigeria, the trend is quite different. Increase in demographic growth in Nigeria, with current population of 120 million people, has lead to a corresponding increase in total fuelwood consumption.
In meeting the resultant rapidly increasing demand, fuelwood traders and loggers are known to cut down tens of hundreds of square kilometres of standing forests, comprising mainly wet wood, to meet urban demands. This profit-oriented energy supply pattern compels fuelwood traders to harvest both dry and wet wood indiscriminately from marginal forests to meet ever growing demands in the urban areas.
Cutting down trees for fuel-wood, as is the practice in rural Nigeria, results to deforestation leading to the disappearance of valuable species of trees, some of which could be used to improve crop varieties and increase agricultural yield, the mainstay of the rural poor. The Federal Environmental Protection Agency (FEPA) recently estimated that Nigeria is annually losing over 600,000 hectare of the total 9.6 million hectares forest cover to deforestation as a result of fuelwood exploitation, uncontrolled logging and bush burning. Closely related to this trend is the decline of peoples' health in the rural areas, where 90% of the inhabitants turn to the surrounding forests to treat their ills.
Fauna species loss
Reducing the size of the forests for fuelwood often destroys the habitat of valuable species of animals, sometimes leading to their extinction. Of the 274 classified mammal species in Nigeria, thirty are already endangered, of which almost half are on the brink of extinction. A significant feedback effect is that vital species such as the pollinating insects, that ensure the maintenance of yield and stocks, are destroyed when forests are cut down.
When trees are cut down, the soil loses its capacity to check surface run-off. This trend, apart from causing erosion, reduces the fertility of the topsoil and its ability to regenerate vital nutrients. Soil erosion and desertification are now damaging agricultural land development and productivity of the southern and northern agricultural zones of Nigeria. Treeless rural farmlands are known to be washed away in agricultural neighbourhoods in the south. In the rural areas of the northern grasslands, overgrazing, together with grass harvesting for fuel, have resulted in an annual loss of over 350,000 square kilometres of pasture to advancing desert.
Loss of soil fertility
Left undisturbed, a forest recycles its own nutrients from leaves, twigs, and agricultural residues like corn stalk, corn cobs, rice stalk, dung etc, scattered on the forest's surface. When these residues are removed from marginal lands for cooking or for processing into briquettes, as is the typical practice in rural Nigeria, the soil is deprived of the vital nutrients that these residues would have provided. Crop failures in rural Nigeria in the 1990s have been attributed to this phenomenon. In addition, greenhouse gases, including nitrous oxide, carbon dioxide and methane, which lead to global warming, are released into the air.
Tropical tree species often consist of male and female trees. Bats, pollinating insects, and birds carry pollen grains from the male to the female tree flowers, However, this service can only be provided if the trees grow sufficiently closely to be within the flying radius of the animals or insects. If the distance becomes too great, the trees are no longer able to regenerate.
Biomass energy and climate link
Biomass resources are able to soak up the excess carbon from energy-related activities, replenishing the atmosphere with the oxygen needed for our health. But when forest is cleared and burnt for fuelwood this function is lost and the environment is worse for it. If just two-thirds of the estimated 9.6 million hectares of forest and woodlands in Nigeria is actively maintained, rather than cleared or just left to decay, it could absorb over 50% of the carbon dioxide emissions from burning fossil fuel and dung in the homes of more than 70 million rural dwellers in Nigeria.
When rain falls on to the forest, the trees act like a huge sponge that absorbs and hold the rainwater. The water evaporates from the trees, causing clouds, which again give rain to the surrounding areas. If the forests are removed, the rain falling on the surrounding farmlands is reduced, leading to barren agricultural lands.
Environmental health and the use of biomass energy
About two-thirds of the estimated 84 million rural dwellers, mostly women and children, live in communities experiencing severe biomass energy crises due to deforestation. They rely on inferior agricultural residues such as corn stalk, maize cob, groundnut husk, cotton husk, rice husk, barks, etc, to cook meals often in poorly ventilated kitchens and mostly on unvented traditional open fires.
Most of these residues are of low calorific value having high moisture content. Field reports have shown that some rural women, who are hard hit by the prevailing biomass scarcity in Nigeria, gather wet barks and relatively dry maize cobs to cook. Most of these residues have moisture contents of more than 45%. As a result, they produce high levels of emissions of carbon monoxide (CO), sulphur dioxide (SO2), and total suspended particles (TSP). When they are burnt, especially in poorly ventilated enclosure, they cause high concentrations of air pollution.
Studies from epidemiological literature indicate that exposures to low quality fuel such as diverse types of agricultural residues contribute significantly to the high mortality and morbidity rates among rural women.
Most communities are organised around farmstead where the inhabitants spend more time in and around their homes, occasionally going into the farms to tend their crops. Even when working on the farm, or relaxing, cooking is done inside the home. As a result of this trend, the Nigerian rural dwellers spend a significant part of their time, about 70%, indoors because all activities from farming to eating to sleeping revolve round the home. Smoke from stoves damages the health of these rural dwellers who often live in poorly ventilated homes where 98% of cooking is done with biomass residues.
Figure 1: In Nigeria, 90% of cooking is done on inefficient stoves such as this
Environmental protection measures are unaffordable to many of the rural people of Nigeria and elsewhere. Common sense however calls for a sustainable management of biomass resources if exploitation is inevitable. Such management measures can be achieved by adopting the production and use of energy-efficient cooking stoves. Also tree planting should be intensified to maintain stocks. In these ways, livelihoods can be sustained, while care is taken of the environment for the future generation of rural dwellers.
Mr. Joe Obueh specializes in the environmental aspect of household energy, and has special interest in gender, poverty alleviation, resource conservation and research issues.
Federal Environmental Protection Agency FEPA (1992), Report for the
United Nations Conference on Environment and Development Rio de Janeiro, Brazil, June 1992 Pp 16-17.
United States Environmental Protection Agency (1989) EPA Journal, Vol. 15 #1 January/February issue. 1989 Pp 44.