Emissions Scenarios - IPCC

Emission Scenarios 277
Box 5-3: Sulfur Emissions in Ше AIB-AIM Mariier Scenario
In the AIB-AIM marker scenario, global SO2 emissions increase rapidly from 70.6 MtS m 1990 to reach a peak around 2020
at 101 MtS, and subsequently decline to around 30 MtS after 2050. The global SOj emission trajectory follows that of the
developing countries, for which emissions mercase because of the rapid growth of fossil fuel use driven by rapid economic
development, combined with a lack of sulfur controls that reflect investment and infrastracture limitations. With an increase m
personal incomes in developing countries and associated concems about local air pollution, SO2 becomes controlled in a similar
way to that in developed countries, for which SOj emissions have declined in the past two decades.
The sources of SOj emissions tracked by the AIM model include energy use, industrial production processes (steel and cement
production), and biomass buming.
The major factors of SOj emission reduction are changes in the fuel mix, use of advanced energy technology, and
implementation of desulfurization technology. In the AIB-AIM scenario, the volume and share in total primary energy of coal
and crade oil changes drastically over time (Table 5-10).
Table 5-10: Coal and crude oil in the Al-AIM scenario in terms of primary energy requirements (EJ) and as shares of total
primary energy (%).
1990 2050 2100
Coal 85 EJ 24.6% 140 EJ 77.7% 41 EJ 2.0%
Crade oil 126 EJ 36.5% 181 EJ 15.0% 107 EJ 5.0%
Before 2050, both advanced energy technology and desulfurization play a key role in the SO2 emissions reduction. In the power
generation sector, integrated gasiñcation combined cycle (IGCC), fluidized bed combustion (FBC), and flue-gas desulfurization
(FGD) technologies are adopted. In the industry and commercial sectors, FBC boilers, fuel desulfurization and FGD are
adopted. SOj emission reductions are also achieved in the transport sector. Table 5-11 summarizes the SO2 abatement effect of
these technologies.
Table 5-11: SO., emission reductions (%>) by technology and sector in the Al-AIM scenario.
Technologies SO, Emission reduction rate Note
Power generation
IGCC 96% Introduced after 2015
FBC 95%
FGD 98%
Industry and commercial sector
FBC 92%
FGD 95%
Fuel desulfurization 70%
TVansport sector
SO2 emission confrol 75%
Income levels determine the time at which these technologies are introduced in the AIB-AIM scenario. According to the
experience of SO2 emission controls in developed countries, low-income developing countries will start to introduce SOj
emission control technologies when GDP reaches around US$3500 per capita in 1990 dollars. In AIB-AIM this threshold level
is reached in a period of about 30 years.