| Boiling Point | |
![]() Issue 54 (2007) Climate change and household energy | |
| Article | Health and Greenhouse Gas Impacts of Biomass and Fossil Fuel Energy Futures in Africa |
| Author | Robert Bailis, Majid Ezzati, Daniel M. Kammen |
![]() Figure 1: Current per-capita biomass production in SSA. The colors show total wood fuel consumption and the pie charts show the fraction of wood that is used for charcoal based on multiple sources. FAO biomass estimates (including charcoal) [3] were roughly consistent with IEA estimates and used for all countries except Angola, Kenya, South Africa, Sudan, and Zambia (20% of the region’s population). For these countries FAO biomass estimates would have been too low to meet minimal household energy needs, when considered with energy use from fossil fuels and other energy sources reported by IEA [2]. In all of these countries except Kenya, IEA estimates were used; for Kenya, data from a detailed national household fuel consumption study was used [25]. |
![]() Table 1: Scenarios of household energy futures in SSA. All scenarios begin from the same 2000 baseline. In 2000, 64% of the population lived in rural areas. 41%, 34%, 13%, 8% and 4% of urban households used wood or crop residues, charcoal, kerosene, LPG and electricity as their primary source of household energy, respectively; 94%, 4%, and 2% of rural households used wood or crop residues, charcoal, and kerosene. Future population and urbanization estimates were from the United Nations Population Division. Future household energy use and production scenarios examine the role of two factors: household fuel choice and biomass harvesting and charcoal production techniques. The rate of adoption of alternative fuels and sustainability practices were also examined (gradual versus rapid scenarios). |
![]() Figure 2: Number of people in SSA using each fuel in BAU, charcoal (C and RC), and fossil fuel (F and RF) scenarios. In C between 2000 and 2050, the absolute number of people using charcoal increases more than 10-fold, partly driven by population growth and urbanization and partly by a shift to charcoal. This is a large, but empirically realistic shift. For example, between 1980 and 2000, the number of households using charcoal as a primary source of energy in Kenya increased by about 250%, despite frequent attempts by the Kenyan government to restrict charcoal production [25]. “Other” includes crop residues, dung, and mineral coal. |
![]() Figure 3. Cumulative GHG emissions from 2000 and 2050 from CO2, CH4, and N2O converted to CO2 equivalent units, weighted by 100-year-GWP for each scenario of SSA household energy futures. Totals are disaggregated by emissions from each fuel. The figure also shows cumulative emissions as fractions of regional and global cumulative emissions (118 GtC and 917 GtC respectively, based on the median emissions scenario reported in the Special Report on Emissions Scenarios (SRES) to inform policy makers during the IPCC’s Third Assessment period [13]). See Fig S9 for annual emissions from each scenario. The figure presents the sum of emissions of GHGs targeted by the Kyoto Protocol (KP): CO2, CH4, and N2O. This omits warming effects of carbon monoxide (CO), non-methane hydrocarbons (NMHCs), and aerosols or particulate matter (PM). These non-KP GHGs were included in sensitivity analysis along with analysis based on a 20-year GWP. |
![]() Figure 4. Estimated mortality for scenarios of household energy futures in SSA. Diseases included are LRIs among children < 5 years of age and COPD among adult women. Estimates account for forecasted demographic change (population growth and aging) and secular trends in background disease and mortality levels. The observed secular (BAU) decline in childhood LRI mortality is a result of factors such as increased coverage and efficacy of pneumonia case management using antibiotics; increased awareness and practice of breastfeeding, which increases child immunity and survival; and other secular trends caused by economic and technological factors (29). Secular (BAU) trends in COPD are upward mainly because of population aging (COPD mortality increases with age). There has been a slight increase in age-specific COPD mortality rates at older ages, possibly due to small increases in smoking among women in Africa, and a slight decrease in age-specific rates in middle ages, possibly due to competing causes of death (mainly human immunodeficiency virus/acquired immunodeficiency syndrome). Similar directions are seen for lung cancer, another disease affected by smoking, which is the main driver of secular COPD rates in Africa. |
Health and Greenhouse Gas Impacts of Biomass and Fossil Fuel Energy Futures in Africa by Robert Bailis, Majid Ezzati and Daniel M. Kammen (586 KB)![]() . |