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close this bookThe Global Greenhouse Regime. Who Pays? (UNU, 1993, 382 p.)
close this folderPart III National greenhouse gas reduction cost curves
close this folder9 Carbon abatement potential in West Africa
View the document(introduction...)
View the documentIntroduction
View the documentLong-term energy and carbon emissions scenarios
View the documentOptions for rational energy use and carbon conservation
View the documentEconomic opportunities for implementation
View the documentPolicy issues for the region
View the documentConclusions
View the documentReferences

Long-term energy and carbon emissions scenarios

West Africa forms about a fifth of Africa's land area, but has about a third of its population, a third of which in turn live in urban areas. The sixteen countries of West Africa are socially and economically diverse, but their economies are dominated by a few sectors.

Energy production and use

Except for hydropower resources (which are found in most countries), only Nigeria has significant fossil energy resources. Energy consumption varies greatly among West African countries depending on their economic development. They remain highly dependent on biofuels, especially in the residential sector. Over 70 per cent of the total energy used in the region is from biomass, mostly in the form of firewood and charcoal. Biomass fuels are cheap and easy to use and reduce the oil import bills for some countries. Biomass conversion technologies, however, are very inefficient (15-20 per cent). The region also faces an acute and increasing scarcity of biomass fuels. About half of the non-desert areas in West Africa are projected to suffer from fuelwood scarcity by the end of the century. Environmental and health concerns also pose problems with expanding biomass fuel supplies.

Energy scenarios

Limited data make it difficult to project the future energy paths of West Africa. Studies by IIASA and IPCC estimated future energy use for Africa. However, their level of aggregation and poor linkage to carbon emissions makes them of limited utility for this study. National plans in the region also do not give the requisite information. However, a recent study by the Lawrence Berkeley Laboratory provides a sound basis for an initial investigation of long-term energy and carbon emissions scenarios for the region. Among the 17 countries studied, there were three West African countries: Ghana, Nigeria and Sierra Leone. In total, they contain about 20 per cent of the land area of the region and 69 per cent of the population (due to Nigeria's large size). In addition, they consume almost 60 per cent of the region's total energy.

I created long-term scenarios by using an end-use methodology that estimates energy consumption as a function of expected changes in national economic and demographic structures and fuel intensities. These changes were assumed to be strongly affected by growth in GDP, population and fuel prices. Primary supply and delivered energy were estimated for each end-use sector. The scenarios then aggregated energy supplies by fuel type required to meet the sectoral end-use demands, relying on real GDP as the indicator of overall economic activity.

Two energy and associated carbon emissions scenarios were constructed for each country. The scenarios focused on the situation in 2025 rather than a quantitative path over time. The base year was set as 1985 (except for Ghana where 1937 was used). The first scenario assumed 'lousiness as usual' and was called the High Emissions Scenario (HES). The second scenario introduced measures to increase efficiency and to restrain carbon emissions and is referred to as the Low Emissions Scenario (LES). Both scenarios incorporated the same basic economic and demographic assumptions (see Table 9.1).

Demographic and economic assumptions

The population of Africa grows at more than 3 per cent annually, the highest rate in the world. Population in West Africa grows at a rate only slightly lower than that of the whole continent. However, the scenarios assumed a slower growth rate in recognition of regional family planning activities, improved education, and the recent adoption of a population policy in Nigeria, the most populous country in Africa. The scenarios assume that populations in the region will increase between two-and-a-half and three times between 1985 and 2025. For comparison, the World Bank has used an even slower growth rate, projecting 34 million by the year 2025 for Ghana versus 43 million in this study; and 255 million for Nigeria in 2025 versus 317 in this study. This author and the World Bank use almost the same figure for Sierra Leone.

Table 9.1 Demographic and economic data, Ghana, Nigeria, Sierra Leone

  Ghana Nigeria Sierra Leone
1987 2025 1985 2025 1985 2025
Population (millions) 13.4 42.7 96 317 4 9
Population AAGR (%) - 2.9 - 3.0 - 2.3
GDP (US$ billion! 4.59 22.76 75.0 373.0 0.87 2.88
GDP/capita (US$) 343.0 533.0 788.0 1176.0 247.0 327.0
GDP AAGR (%) - 4.0 - 4.0 - 3.0
GDP/capita AAGR(%) - 1.2 - 1.0 - 0.7

AAGR annual average growth rate

In contrast to rising population, economic growth in the region has fallen in the last two decades. High oil imports and low export commodity prices combined with poor local response strategies were responsible for this poor economic performance. In addition, Ghana suffered from serious drought in the early 1980s, which crippled agricultural production. The drought also lowered the water level of the Volta dam that generates over 97 per cent of Ghana's electricity. In Nigeria, the oil price boom since the mid-1970s led to a spurt of unprecedented GDP growth. The subsequent decline in oil prices and weak internal policies left the economy floundering. In Sierra Leone, excessive public spending between 1979 and 1981 and reduced foreign exchange earnings since the mid 1970s have reduced its ability to import oil. The resultant energy shortages have been disastrous.

All these countries instituted economic reforms recently. Ghana's policies revived GDP growth which reached 6 per cent in the latter part of the 1980s. Nigeria's reforms improved its GDP growth rate to 4 per cent annually over the same period. Sierra Leone is emulating some of Ghana's more successful measures.

In light of these developments, the scenarios assumed GDP growth rates of 3-4 per cent up to the year 2025. For comparison, the International Panel on Climate Change assumed slightly more than 4 per cent for their high growth case; and less than 3 per cent for their lower growth case. In the scenarios, these growth rates result in a five-fold increase in the GDPs of Ghana and Nigeria by 2025, and a three-fold increase for Sierra Leone.

Sectoral analysis of carbon emissions

The scenario applies carbon emission coefficients to the resulting sectoral patterns of energy transformation and end use. The residential, transportation and industrial sectors combined account for over 80 per cent of the carbon emissions (from fossil fuel and biomass usage) in the base year and in 2025 in both the HES and LES in Ghana, and over 90 per cent in Nigeria and Sierra Leone (see Figure 9.2).

In the base year, the transport sector generates most carbon - 59 per cent in Ghana, 53 per cent in Nigeria and 65 per cent in Sierra Leone. By 2025, the anticipated increase in the use of liquefied petroleum gas (LPG) and kerosene in households makes the residential sectoral emissions surpass those of the transport sector in Ghana and Nigeria. In addition, Nigeria is building a natural gas plant that will increase emissions from the domestic and industrial sectors in Nigeria by 2025.

Figure 9.2 Carbon emissions from energy use, Ghana, Nigeria and Sierra Leone

Table 9.2 Primary energy supply and delivered energy demand, Ghana, Nigeria, Sierra Leone

  Ghana Nigeria Sierra Leone
1987 HES 2025 LES 1985 2025 HES LES 1985 2025 HES LES
Primary Energy Supply
Total 232 884 707 1482 4117 3205 56 130 108
Cool(%) 0 0 0 0 6 5 0 0 0
Oil (%) 14 22 20 27 45 39 30 48 46
Natural gas (%) 0 5 0 8 22 30 0 0 0
Biomass (%) 64 39 36 62 23 21 70 46 49
Hydro and renewables (%) 22 34 44 3 4 5 0 6 5
Delivered Energy Demand
Total 192 616 474 1345 3292 2617 53 118 100
Coal (%) 0 0 0 1 4 4 0 0 0
Oil (%) 16 27 27 28 50 44 25 45 46
Natural gas (%) 0 0 0 2 7 15 0 0 0
Biomass (%) 78 56 54 69 29 26 74 51 50
Electricity (%) 7 17 19 2 10 11 1 4 4
Residential 130 358 270 983 1584 1231 41 75 61
Oil (%) 4 24 26 7 31 35 4 15 15
Natural gas (%) 0 0 0 0 0 1 0 0 0
Biomass (%) 95 63 61 92 56 50 95 80 81
Electricity (%) 1 13 13 1 12 14 1 5 5
Transport 19 52 38 259 691 484 10 32 29
Oil 100 100 100 100 100 100 100 100 97
Biomass (%) 0 0 0 0 0 0 0 0 3
Industrial 24 135 109 92 939 832 2 11 10
Coal (%) 0 0 0 2 12 12 0 0 0
Oil (%) 11 13 13 40 45 29 84 91 91
Natural gas (%) 0 0 0 25 23 39 0 0 0
Biomoss (%) 47 45 41 22 6 7 0 0 0
Electricity (%) 41 42 46 11 13 13 15 9 9

HES high emissions scenario
LES: law emissions scenario
All energy quantities shown are in exaJoules (J)

Residential carbon conservation
As is evident in Table 9.2, the residential sector dominates total energy use in African countries. In the scenario's base year, households in all the countries consume around 70 per cent or more of total delivered energy. This dominance stems from the widespread use of inefficient fuelwood and charcoal cooking devices. However, the scenarios assume that the intensity of biomass use (that is, GJ per household) declines by 2025 in all these countries. This outcome follows from two trends that can be discerned, namely, the introduction of improved woodfuel stoves and charcoal kilns, and fuel substitution.

With respect to the latter, the proportion of electrified households in the scenarios is estimated to rise from about 30 per cent today to more than 60 per cent by 2025 in all the countries. In Ghana, for example, the current programme aims at electrifying 90 per cent of households by 2025. The scenarios assume that efficiency improves at point of end use because rising incomes result in the replacement of old, inefficient equipment with new, efficient household appliances and lights. However, most of the old stock will be used second-hand by lower-income households. This transfer will limit the reduction of household electricity demand from efficiency measures. Similarly, substituting oil-based fuels for biomass will improve the quality of life. However, this shift will not reduce carbon emissions.

Innovative consumer financing offers the possibility of introducing much more efficient electrical appliances and lighting systems. If these are incorporated, as in the LES, then household use of electricity could be reduced by about 40 per cent in Nigeria and Sierra Leone, and 30 per cent in Ghana (see Table 9.2). These improvements could be dramatically increased if the devices were designed and made locally and if fiscal measures were employed to reduce the high front-end costs to consumers.

Transport carbon conservation
The large share in carbon emissions of the transport sector is a result of its dependence on oil-based fuels. The rise in incomes postulated in the scenarios will increase the number of vehicles in all countries by 2025. The car fleet will grow even faster than all vehicles as the number of two-car families and imported and locally available second-hand cars will also increase.

Trucks and buses will play a significant role by 2025 in transporting freight and for mass transit, because of the poor quality of railway systems and increased demand for public transport. Transport fuel consumption will grow substantially, but this growth will be moderated by the high cost of imported vehicles and fuel, as has occurred already in Ghana and Sierra Leone. Trip distances are expected to fall in all countries over the next forty years.

Fuel intensities (litres/km) fall in both the HES and LES for all the countries, but this trend is limited by the expected large number of old and inefficient vehicles that are likely to remain in the fleet by 2025. Declines in this ratio of 20 per cent relative to the base year were estimated in the HES for Ghana and Sierra Leone; and 30 per cent for LES. Traffic congestion is assumed to fall in Nigeria thereby lowering its fuel intensity in 2025 to 50 per cent in the HES, and 65 per cent in the LES, of that in 1985. The scenarios for Sierra Leone also introduced some ethanol in light of its success in other African countries. However, ethanol offers great promise to save energy and conserve carbon in the transport sector which may be understated in this study. The scenarios also assume that enacting performance standards for imported vehicles, improving driving practices, and upgrading maintenance facilities will reduce energy demand and carbon emissions.

Industrial carbon conservation
Industrial activities, mainly mining and light and intermediate manufacturing play a limited role in the regional economy. The oil boom in Nigeria stimulated its industrial sector over the last two decades during which industrial production doubled. Industrial activities are expected to expand greatly throughout the region over the timespan of the scenarios. Growth areas are likely to include agro-based industries, petrochemicals, and processing of mining products. By 2025, Nigeria's iron, steel and fertilizer plants are expected to be operating. These activities will boost industrial energy intensive activities in the region.

Gains from energy conservation efforts will be determined largely by international developments due to reliance on imported machinery. As a developmental latecomer, the region can benefit from efficient technologies developed elsewhere, provided that it avoids dumping of old technology. Biomass fuels may also supply a major amount of industrial energy by 2025, thereby reducing the carbon intensity of the manufacturing sector. The adaptation and local manufacture of spare parts for industrial machinery and equipment could further improve industrial energy intensities.

In the LES scenario, Ghana and Sierra Leone reduced carbon emissions due to increased use of agricultural wastes for electricity production in their agro-based industries. In Nigeria, carbon is conserved in industry by increasing usage of natural gas. The LES also incorporated more housekeeping measures resulting from energy auditing and the setting of energy efficiency guidelines for new industries.

Electrical sector carbon conservation
Electricity generation comprises a small but growing share of the total energy demand in the region. Also, due to supply constraints, the level of unfulfilled demand is increasing. These factors explain the very high growth in electricity demand by 2025. In Ghana, for example, it increased eight- and seven-fold in the HES and LES respectively In Nigeria, it increased ten- and eight-fold; and in Sierra Leone, fivefold in both scenarios.

Hydropower will play a major role in expanding electricity supplies in Ghana and Sierra Leone, while Nigeria will rely more on natural gas. Today's high transmission and distribution (T&D) losses will fall from 25-32 per cent to 15-20 per cent by 2025, mainly as result of improving technical efficiencies and less theft of power.

These countries have huge quantities of unexploited hydro resources. Ghana and Nigeria have tapped less than 50 per cent and Sierra Leone only 10 per cent of estimated potential hydropower. In the HES, 80 per cent of Ghana's electricity is generated by hydropower in 2025. In the LES, 100 per cent is supplied by hydropower. Nigeria develops about 75 per cent of its hydro potential in the HES and 95 per cent in the LES. Coal provides only 10 per cent of Nigeria's electricity by 2025 in the HES, and 5 per cent in the LES.

In Sierra Leone, hydropower rises from 3 to 50 per cent of electrical energy in both scenarios. The HES relies on oil to generate the remaining 50 per cent of electricity, and biomass supplies 30 per cent of the shortfall in the LES.

The major constraint on exploiting this hydropower potential is the shortage of capital in the region. The scenarios indicate that electrical demand will increase two to three times faster than GDP by 2025. This trend implies that power projects will require investment capital at the expense of other development sectors - a serious challenge for these countries.

Aggregate analysis of carbon conservation

According to the HES, by 2025 Ghana, Nigeria, and Sierra Leone will emit 4.4, 54 and 1.2 million tonnes of carbon respectively. These projected emissions are a seven- six- and four-fold increase over current emissions for each of these countries. These emissions in 2025 can be reduced by 36 per cent, 25 per cent and 13 per cent respectively if measures to conserve carbon are introduced as assumed in the LES (see Table 9.3).

In all the countries, carbon emissions increase much faster than energy consumption during the four decades because of the shift from biomass to petroleum fuels. In the HES for Ghana and Nigeria, energy demand increases by factors of 2.2 and 2.5 respectively, while carbon emissions increase 6 and 7 times. This shift is less dramatic in Sierra Leone where energy use slightly more than doubles but carbon emissions increase almost fourfold.

In the LES, energy efficiency and carbon conservation measures lower the ratios of energy consumption to carbon emissions in all countries. Growth in carbon emissions surpasses even the high population growth rates of these countries, resulting in increases in carbon emissions per capita between 1985 and 2025 (see Table 9.3). This outcome varies among the countries. It is most pronounced in Nigeria where dependence on fossil fuels increases per capita annual carbon emissions to 171 kg. Ghana's greater reliance on hydropower keeps its per capita carbon emissions down to 104 kg.

Table 9.3 Carbon emissions from Ghana, Nigeria and Sierra Leone

  Ghana Nigeria Sierra Leone
1987 HES 2025 LES 1985 2025 HES LES 1985 2025 HES LES
Carbon emissions (mt) 0.6 4.4 2.7 9 54 41 0.3 1.2 1.0
Residential (%) 15 47 51 21 34 34 19 28 22
Industrial (%) 8 18 10 18 36 37 15 19 20
Transport (%) 59 23 27 53 22 22 65 52 58
Services (%) 7 5 5 2 1 1 1 * *
Agriculture (%) 4 * * 1 2 2 * * *
Losses 6 6 6 5 5 4 * * *
CO2/capita (kg) 48 104 64 99 171 129 93 140 111
CO2/commercial energy(kg/GJ) 3 5 4 6 13 13 6 10 9

HES high emissions scenario
LES: low emissions scenario
* less than 1 per cent

Carbon emitted per unit of commercial energy used also increases between 1985 and 2025 due to the increased use of petroleum based fuels. This feature is well illustrated by Nigeria which will use more and more carbon intensive fuels.

Extrapolated analysis for the region

This three-country analysis provides a basis on which to estimate the future energy use and carbon emissions for the whole West African region. As mentioned above, these three countries comprise most of the region's population and about 60 per cent of its energy use. Both scenarios assumed a region-wide annual population growth rate of 2.9 per cent and a GDP annual growth rate of 4 per cent.

In the HES, carbon emissions increase almost six-fold. In the LES, in which conservation measures are taken, carbon emissions fall by almost a quarter (see Table 9.4). On a per capita basis, carbon emissions increase by 75 per cent in the HES but only 30 per cent in the LES. Expanded use of fossil fuels and the dominant role of Nigeria accounts for the more than twofold increase in carbon emitted per unit of commercial energy used (see Table 9.4).

In short, total energy consumption will increase substantially in the region as will fossil fuel use. But the energy system will also become be more efficient. The transport and industrial sectors observed will become more important throughout the region.

Table 9.4 Extrapolated data for the West African region

  1985 2025 (HES) 2025 (LES)
Population (millions) 169 537 537
Population AAGR (%) - 2.9 2.9
GDP/capita ($US) 551 987 587
Carbon emissions (MtC) 13 77 58.6
CO2/capita (kg) 92 161 120
CO2/commercial energy (kg/GJ) 5.6 12 11.8

HES high emissions scenario
LES low emissions scenario
AAGR annual average growth rate