arise from the climatic cooling effect of SO2, NOx and OC emissions,
and hence the total social cost is indicated separately on top of the
cost bars. For the batch-wise appliances, however, the negative
climate impact is cancelled by high BC emissions in the total.
In urban areas, the health impact due to PM exposure dominates
the overall social cost for most biomass-based appliance types.
Modern gasification technology – having very low PM emissions –
was an exception, and was the only technology category that exhibited
lower social costs than light fuel oil in urban areas. In non-urban areas,
the magnitude of health costs is lower due to lower population density
that is being exposed to the PM emission. As a result, the social costs
for two appliance categories were lower, and for two appliance
categories only slightly higher than those of oil heating.
A comparison of Figs. 3 and 4 indicates a potential misalignment
between marginal policy costs and the social cost of the
externality due to the GHG and air pollutant emissions. Should the
marginal policy cost affect technology choices – e.g. if a policymaker
would put in place energy taxes or other incentives thates.