2.3.2 Drivers of SO 2 and NO x Emissions
The effect of air pollution control can partially or totally offset the additional
emissions caused by growing activity rates, and the combination of pollution control
and activity growth entirely determines China’s emission pathways (Zheng et al.
2018) (Fig. 2.2).
According to the estimates of MEIC, the emissions of SO 2 and NO x slightly
increased during 2010–2013 because emission mitigation just counterbalanced the
additional emissions caused by growing activities. China’s fuel combustion
increased by 15.2% from 2010 to 2013, and its industrial production increased by
14–35% in different industries. During this period, China’s clean air actions mainly
focused on upgrading emission standards for the power and industrial sectors. These
measures effectively offset the growth in activities but were not stringent enough to
reverse the growing trends in emissions; therefore, air pollutant emissions remained
relatively stable from 2010 to 2013.
After 2013, emissions are found to have reduced as a result of pollution controls.
China’s fuel combustion and industrial production have flattened out since 2013,
while high-efficiency mitigation measures have been increasingly implemented in all
emission source sectors, as required by the Clean Air Action. Scenario analysis
suggests that the effect of pollution control rapidly removes air pollutants and
consequently drives down China’s emissions (Fig. 2.2). If pollution control were
frozen at 2010 levels, SO 2 emissions in 2017 could have increased by 167%
compared to the actual data, while NO x emissions could have increased by 38%.
The different reduction rates of air pollutant emissions are determined by the source
sector distributions and emission mitigation efforts of each sector. This decrease is
most notable for SO 2 (emissions are estimated to have decreased by 59% from 2013
to 2017) because the dominant source sectors (i.e., power and industry) both
significantly reduced their emissions. The decrease in emissions is smallest for
NO x (21% of emissions cut from 2013 to 2017 based on the analysis) because the
power sector was the major contributor to emission reduction but only accounted for
one-third of total emissions. To understand the underlying drivers of emission
reduction, we decompose the avoided emissions due to pollution control into sectors
(Fig. 2.4) to identify the main drivers underlying key source categories (Zheng et al.
2018). We select the year of 2017, which exhibited the largest reduction in emissions
according to our calculations, to perform this analysis.
1. The power sector. The generation of electricity from hydrocarbon fuels in China
has increased by 33% since 2010, which has led to increases of 1.2 Tg SO 2 and
1.7 Tg NO x in 2017 compared with their levels in 2010 (Fig. 2.4). Mitigation
efforts have yielded reductions of 7.1 Tg SO 2 and 6.1 Tg NO x and thus totally
offset the emissions caused by growing activities. The reduction of emissions was
achieved through the “ultralow emission” standard. To fulfill the stringent standards, FGD and SCR systems have been increasingly installed at utilities in coalfired power plants, with penetration rates reaching >95% in 2017. Of the current
power plants, 71% have operated close to the design performance of “ultralow
emission” levels (China Daily 2018).
2 Anthropogenic Emissions of SO 2 , NO x , and NH 3 in China
23
The effect of air pollution control can partially or totally offset the additional
emissions caused by growing activity rates, and the combination of pollution control
and activity growth entirely determines China’s emission pathways (Zheng et al.
2018) (Fig. 2.2).
According to the estimates of MEIC, the emissions of SO 2 and NO x slightly
increased during 2010–2013 because emission mitigation just counterbalanced the
additional emissions caused by growing activities. China’s fuel combustion
increased by 15.2% from 2010 to 2013, and its industrial production increased by
14–35% in different industries. During this period, China’s clean air actions mainly
focused on upgrading emission standards for the power and industrial sectors. These
measures effectively offset the growth in activities but were not stringent enough to
reverse the growing trends in emissions; therefore, air pollutant emissions remained
relatively stable from 2010 to 2013.
After 2013, emissions are found to have reduced as a result of pollution controls.
China’s fuel combustion and industrial production have flattened out since 2013,
while high-efficiency mitigation measures have been increasingly implemented in all
emission source sectors, as required by the Clean Air Action. Scenario analysis
suggests that the effect of pollution control rapidly removes air pollutants and
consequently drives down China’s emissions (Fig. 2.2). If pollution control were
frozen at 2010 levels, SO 2 emissions in 2017 could have increased by 167%
compared to the actual data, while NO x emissions could have increased by 38%.
The different reduction rates of air pollutant emissions are determined by the source
sector distributions and emission mitigation efforts of each sector. This decrease is
most notable for SO 2 (emissions are estimated to have decreased by 59% from 2013
to 2017) because the dominant source sectors (i.e., power and industry) both
significantly reduced their emissions. The decrease in emissions is smallest for
NO x (21% of emissions cut from 2013 to 2017 based on the analysis) because the
power sector was the major contributor to emission reduction but only accounted for
one-third of total emissions. To understand the underlying drivers of emission
reduction, we decompose the avoided emissions due to pollution control into sectors
(Fig. 2.4) to identify the main drivers underlying key source categories (Zheng et al.
2018). We select the year of 2017, which exhibited the largest reduction in emissions
according to our calculations, to perform this analysis.
1. The power sector. The generation of electricity from hydrocarbon fuels in China
has increased by 33% since 2010, which has led to increases of 1.2 Tg SO 2 and
1.7 Tg NO x in 2017 compared with their levels in 2010 (Fig. 2.4). Mitigation
efforts have yielded reductions of 7.1 Tg SO 2 and 6.1 Tg NO x and thus totally
offset the emissions caused by growing activities. The reduction of emissions was
achieved through the “ultralow emission” standard. To fulfill the stringent standards, FGD and SCR systems have been increasingly installed at utilities in coalfired power plants, with penetration rates reaching >95% in 2017. Of the current
power plants, 71% have operated close to the design performance of “ultralow
emission” levels (China Daily 2018).
2 Anthropogenic Emissions of SO 2 , NO x , and NH 3 in China
23