HR: 08:45h
AN: U31A-03 INVITED [PDF]
TI: Greenhouse Gas and Particulate Emissions and Impacts from
Cooking Technologies in Africa
AU: Kammen, D M
EM: kammen@socrates.berkeley.edu
AF: Energy and Resources Group, University of California, Berkeley, CA 94720-3050 United States
AU: Kammen, D M
EM: kammen@socrates.berkeley.edu
AF: Goldman School of Public Policy, University of California, Berkeley, CA 94720-3050 United States
AU: * Bailis, R
EM: rbailis@socrates.berkeley.edu
AF: Energy and Resources Group, University of California, Berkeley, CA 94720-3050 United States
AU: Kituyi, E
EM: e.kituyi@cgiar.org
AF: African Center for Technology Studies
&
University of Nairobi, P.O. Box 45917, Nairobi, 45917
Kenya
AU: Ezzati, M
EM: mezzati@hsph.harvard.edu
AF: Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115 United States
AB:
In much of Africa, the largest fraction of energy consumption occurs within the residential sector and is derived primarily
from woodfuels burned in simple stoves with poor combustion characteristics. Many of the products of incomplete combustion
(PICs) are damaging to human health, particularly when they are concentrated in poorly ventilated indoor environments.
Incomplete combustion also has potentially harmful impacts on the climate. Prevalent PICs include methane, a potent
greenhouse gas (GHG) that is among the pollutants subject to controls under the Kyoto Protocol as well as carbon monoxide
(CO), non-methane hydrocarbons (NMHCs) and particulate matter (PM), which can all have an effect on climate, but are not
subject to controls under Kyoto. In addition, when woodfuels are used at a rate that reduces standing stocks of trees over
the medium or long term, the CO2 released by combustion also has an impact.
The choice of stove and fuel technology can have a significant impact on the emission of GHGs as well as on human exposure to
health damaging pollutants. In this paper we analyze the emissions of different household energy technologies on a
life-cycle basis. We use emission factors to estimate the emissions associated with production, distribution and end-use of
common household fuels and assess the likely impacts of these emissions on public health and the global environment. We focus
largely on charcoal, a popular fuel in many sub-Saharan African countries. Charcoal is produced by heating wood in the
absence of sufficient air for complete combustion to occur. This process removes moisture and most of the volatile compounds.
The compounds driven off in the process consist of condensable tars as well as many gaseous hydrocarbons, including ~40 g
CH4 per kg of charcoal produced. Combining upstream and end-use emissions, every meal cooked with charcoal has 2-10 times the
global warming effect of cooking the same meal with firewood and 5-12 times the effect of cooking the same meal with LPG or
kerosene.
When charcoal is produced in large quantities, as it is in Africa, the net warming effect can exceed the impact from the
"modern energy sector" (transportation and industry) by 50-100 percent, even if charcoal is produced on a sustainable cycle
so that all of the wood harvested for charcoal production is allowed to regenerate. However, while charcoal may be worse than
firewood with respect to greenhouse gas emissions, it is an improvement with respect to exposure to health damaging
pollutants, particularly particulate matter (PM). Levels of PM in households using charcoal are over 90 percent lower than
households using open wood fires (316 -(159) mg/m3 for households using charcoal in a common improved stove compared to 3764
(360) mg/m3) for households using wood in open fires: mean (standard error)). These differences in exposure are consistent
with 30 and 50 percent reductions in the incidence of acute respiratory infection (ARI) in adults and children under 5
respectively. Reconciling the costs and benefits of different household energy technologies creates a difficult policy
challenge, particularly with the severe budgetary and resource constraints that household consumers and government agencies
face in sub-Saharan Africa.
UR: http://socrates.berkeley.edu/~rael
DE: 0345 Pollution--urban and regional (0305)
DE: 1610 Atmosphere (0315, 0325)
DE: 6304 Benefit-cost analysis
DE: 6309 Decision making under uncertainty
DE: 9810 New fields (not classifiable under other headings)
SC: U
MN: 2003 Fall Meeting