Air Quality Impact of Diffuse and Inefficient Combustion Emissions in Africa (DICE-Africa)

Anthropogenic
pollution in Africa is dominated by diffuse and inefficient
combustion sources, as electricity access is low and motorcycles and
outdated cars proliferate. These sources are missing, out-of-date,
or misrepresented in state-of-the-science emission inventories. We
address these deficiencies with a detailed inventory of Diffuse and
Inefficient Combustion Emissions in Africa (DICE-Africa) for 2006
and 2013. Fuelwood for energy is the largest emission source in DICE-Africa,
but grows from 2006 to 2013 at a slower rate than charcoal production
and use, and gasoline and diesel for motorcycles, cars, and generators.
Only kerosene use and gas flaring decline. Increase in emissions from
2006 to 2013 in this work is consistent with trends in satellite observations
of formaldehyde and NO2, but much slower than the explosive
growth projected with a fuel consumption model. Seasonal biomass burning
is considered a large pollution source in Africa, but we estimate
comparable emissions of black carbon and higher emissions of nonmethane
volatile organic compounds from DICE-Africa. Nitrogen oxide (NOx ≡ NO + NO2) emissions
are much lower than from biomass burning. We use GEOS-Chem to estimate
that the largest contribution of DICE-Africa to annual mean surface
fine particulate matter (PM2.5) is >5 μg m–3 in populous Nigeria.