3. 1. 2 Emission Trends and Cause of Changes
Although air pollutant emissions have been estimated since 1999, comparisons with past data are difficult due to annual additions of new emission sources or improvements in estimation methods. Since 2007, anthracite coal imports were added to the emissions estimate, CleanSYS emissions data were used, and the VOCs’ emission factors were changed, resulting in large shifts in emissions for the related substances. In 2011, improvements to emission estimates continued to be pursued, with the addition of PM2.5 emissions and new emission sources such as industrial processes, improvement of the car emission factors for transport, and use of control efficiency due to oil mist collection facilities in the energy transport and storage sector. In 2012, the estimation methodology was improved in the non-road transport (construction machinery) sector, and the food and drinks manufacturing (whiskey and other spirits) and VOCs emission factors were improved. In 2014, fishing vessels and leisure boats were added to the ships sector, and the methodology for the roads sector was also improved, such as using NOx emissions factors that reflects the actual road driving conditions. In this report, we present emissions over the last 5 years, from 2011 to 2015, and analyze and describe the main causes of change from 2014 to 2015. The major trends in air pollutant emissions are described below.
CO Emissions
The annual trends in CO emissions are shown in Fig. 2 and Table 2; recently, there has been an overall decrease in emissions. Road transport emissions, which accounted for 31.0% of CO emissions in 2015, decreased by 35,709 metric tons (12.7%) compared to the previous year. This was the result of a 10.5% reduction in vehicle kilometers traveled (VKT) by small passenger cars (2014: 13.624 billion km → 2015: 12,195 billion km). In the non-industry category, which also accounts for a high percentage of CO emissions, use of anthracite coal for heating decreased by 9.6% compared to the previous year (2014: 1,628,911 metric tons → 2015: 1,473,094 metric tons), leading to a 5.6% (4,295 metric tons) decrease in emissions. In the energy production category, emissions decreased 4.7% (2,718 metric tons); this was due to a 19.5% decrease in emissions in the public power generation category, the result of a 42.4% decrease in LNG consumption (2014: 12.210943 billion m3 → 2015: 7.038176 billion m3). Conversely, in the non-road transport category, CO emissions increased 17.1% (9,597 metric tons) compared to the previous year due to an increase in the mean operating rate of construction machinery (2014: 40.71% → 2015: 41.55%).
Fig. 2.
Trends in CO emissions, by emission source, in the last 5 years.
Table 2.
Trends in CO emissions, by emission source, in the last 5 years.
(units: metric tons/year)
Source category |
2011 |
2012 |
2013 |
2014 |
2015 |
Change |
Energy production |
56,202 |
59,190 |
63,457 |
57,856 |
55,138 |
-4.7% |
Non industry |
79,804 |
79,152 |
87,532 |
76,594 |
72,299 |
-5.6% |
Manufacturing industry |
19,179 |
19,141 |
20,125 |
18,716 |
16,854 |
-9.9% |
Industrial processes |
21,406 |
20,648 |
24,912 |
25,855 |
26,069 |
0.8% |
Road transport |
463,543 |
442,672 |
409,218 |
281,225 |
245,516 |
-12.7% |
Non-road transport |
68,290 |
72,950 |
82,615 |
126,103 |
135,700 |
7.6% |
Waste |
1,861 |
3,300 |
1,957 |
1,645 |
1,548 |
-5.9% |
Other |
8,060 |
6,533 |
6,865 |
6,459 |
7,197 |
11.4% |
Biomass burning |
262,282 |
260,903 |
255,206 |
231,917 |
232,455 |
0.2% |
Total |
980,626 |
964,490 |
951,888 |
826,370 |
792,776 |
-4.1% |
NOx Emissions
The annual trends in NOx emissions are shown in Fig. 3 and Table 3; in the last 5 years, there has been an overall increase in emissions. In 2015, NOx emissions increased 13,220 metric tons compared to the previous year. This was due to increased emissions in the non-road transport, road transport, and industrial processes categories. Non-road transport, which accounted for 26.3% of total NOx emissions, is showing a continually increasing trend. In 2014, emissions estimation methodology was constructed for new emission sources in the ships category (fishing vessels and leisure boats); the extra emissions resulted in an increase from 89,887 metric tons in 2013 to 144,030 metric tons. In 2015, an increase in the mean operating rate of construction machinery (2014: 40.71% → 2015: 41.55%) led to a 4.9% increase (13,205 metric tons) in emissions from that source. The road transport category has shown an increasing trend since 2014, and increased by 2.3% in 2015 compared to the previous year, reaching 369,585 metric tons. The VKT of large and small freight cars increased 10.4% (2014: 8.874 billion km → 2015: 9.800 billion km) and 2.9% (2014: 35.212 billion km → 2015: 36.241 billion km), respectively, compared to the previous year, resulting in an increase in emissions. The VKT of small RVs also increased 6.1% (2014: 38.931 billion km → 2015: 41.317 billion km), contributing to the increase in emissions.
Fig. 3.
Trends in NOx emissions, by emission source, in the last 5 years.
Table 3.
Trends in NOx emissions, by emission source, in the last 5 years.
(units: metric tons/year)
Source category |
2011 |
2012 |
2013 |
2014 |
2015 |
Change |
Energy production |
166,709 |
169,346 |
177,219 |
162,818 |
150,818 |
-7.4% |
Non industry |
90,876 |
87,935 |
88,769 |
81,143 |
82,948 |
2.2% |
Manufacturing industry |
181,219 |
172,761 |
178,034 |
173,660 |
169,139 |
-2.6% |
Industrial processes |
53,077 |
59,002 |
55,151 |
53,311 |
59,830 |
12.2% |
Road transport |
322,307 |
345,666 |
335,721 |
361,230 |
369,585 |
2.3% |
Non-road transport |
217,098 |
225,561 |
246,027 |
291,171 |
304,376 |
4.5% |
Waste |
8,732 |
14,782 |
9,529 |
12,257 |
11,977 |
-2.3% |
Other |
197 |
154 |
165 |
153 |
172 |
12.6% |
Biomass burning |
9,221 |
9,177 |
9,110 |
8,765 |
8,883 |
1.3% |
Total |
1,049,435 |
1,084,383 |
1,099,723 |
1,144,508 |
1,157,728 |
1.2% |
On the other hand, energy production, which accounts for 13.0% of total NOx emissions, decreased 7.4% (12,000 metric tons) relative to the previous year. This appears to be due to a 42.4% decrease in LNG usage at public power generation facilities (2014: 12.210943 billion m3 → 2015: 7.037176 billion m3) and a 15.4% decrease in LNG usage at district heat production plants (2014: 2.367650 billion m3 → 2015: 2.003366 billion m3). Manufacturing industry, which accounts for 14.6% of emissions, also decreased by 2.6% (4,521 metric tons) compared to the previous year; this was due to decreases in anthracite coal (2014: 1.961 million metric tons → 2015: 1.281 million metric tons) and LNG usage (2014: 4.694507 billion m3 → 2015: 3.196508 billion m3), which are included in the ‘Other’ subcategory for this emission source.
SOx Emissions
As shown in Fig. 4 and Table 5, SOx emissions, which are heavily affected by the sulfur content of fuel, showed an overall decreasing trend (2011: 434,113 metric tons → 2015: 352,292 metric tons). However, in 2015, emissions increased by 9,131 metric tons compared to the previous year. Due to the continual expansion of low sulfur fuel supply policies and clean fuel use policies, fuel’s sulfur content has been decreasing, including diesel, kerosene, and gasoline (Table 4). This has resulted in decreasing SOx emissions in the fuel combustion categories, such as energy production and non-industry, as well as the transport categories.
Fig. 4.
Trends in SOx emissions, by emission source, in the last 5 years.
Table 4.
Annual sulfur content of major fuel types.
(units: wt%)
Fuel |
2011 |
2012 |
2013 |
2014 |
2015 |
Bunker-C fuel oil (4.0%) |
3.228 |
3.11944 |
3.10624 |
2.98658 |
3.01056 |
Diesel (0.001%) |
0.001 |
0.00053 |
0.00053 |
0.00048 |
0.00054 |
Kerosine |
0.05 |
0.05 |
0.00041 |
0.00046 |
0.0006 |
Regular unleaded gasoline |
0.001 |
0.00049 |
0.00045 |
0.00047 |
0.00047 |
*Source: Korea Petroleum Quality & Distribution Authority, sulfur content for each fuel type
Table 5.
Trends in SOx emissions, by emission source, in the last 5 years.
(units: metric tons/year)
Source category |
2011 |
2012 |
2013 |
2014 |
2015 |
Change |
Energy production |
84,464 |
91,053 |
97,565 |
94,562 |
91,243 |
-3.5% |
Non industry |
53,957 |
40,245 |
31,101 |
24,668 |
28,736 |
16.5% |
Manufacturing industry |
109,878 |
96,617 |
95,836 |
82,982 |
85,098 |
2.5% |
Industrial processes |
109,342 |
117,191 |
108,333 |
98,927 |
105,385 |
6.5% |
Road transport |
366 |
211 |
189 |
183 |
209 |
13.7% |
Non-road transport |
67,557 |
65,188 |
65,119 |
39,991 |
39,424 |
-1.4% |
Waste |
8,395 |
7,140 |
6,517 |
1,846 |
2,119 |
14.8% |
Biomass burning |
154 |
153 |
148 |
80 |
79 |
-1.5% |
Total |
434,113 |
417,798 |
404,808 |
343,241 |
352,292 |
2.6% |
In 2015, emissions from industrial processes, which accounted for 29.9% of total SOx emissions, increased 6.5% (6,458 metric tons) compared to the previous year. This was due to an emissions increase of 20.1% (5,938 metric tons) in the iron and steel industry, which was the result of increased CleanSYS emissions from some sites (CleanSYS SOx emissions from the pertinent sites, 2014: 8,403 metric tons → 2015: 10,473 metric tons). Non-industry emissions increased 16.5% (4,068 metric tons) compared to the previous year; this was because of a 21.6% increase (2014: 2.012 million kL → 2015: 2.448 million kL) in Bunker-C fuel oil (4.0%) usage at commercial and public institutions. Manufacturing industry accounts for 24.2% of total SOx emissions and increased by 2.5% (2,116 metric tons) compared to the previous year. This was due to an 8.6% increase (2014: 6.500 million metric tons → 2015: 7.058 million metric tons) in the use of anthracite coal for industrial purposes, such as iron and steel, cement, and other uses. On the other hand, emissions in the Energy production category, which account for 25.9% of total emissions, decreased 3.5% (3,319 metric tons) compared to the previous year. This was due to a 1.6% increase (2014: 79.608 million metric tons → 2015: 80.860 million metric tons) in the use of bituminous coal at public power generation plants.
Particulate Matter (TSP, PM10, PM2.5, BC) Emissions
Among particular matter, PM2.5 emissions were first estimated and reported in 2011, and black carbon (BC) emissions were first estimated in 2014. In terms of PM2.5, manufacturing industry, which accounts for 36.8% of total PM2.5 emissions, increased 19.8% (5,996 metric tons) compared to the previous year; this was due to an 8.6% increase (2014: 6.500 million metric tons → 2015: 7.058 million metric tons) in the use of anthracite coal for industrial purposes, such as iron and steel, cement, and other uses. Non-road transport, which accounts for 14.3% of total PM2.5 emissions, increased by 3.2% (435 metric tons) compared to 2014. This was due to a 3.6% increase in the number of registered construction machines (Table 6), and an increase in construction machinery’s mean operating rate (2014: 40.71% → 2015: 41.55%).
Table 6.
The number of registered construction machines.
(units: number of machines)
Type of construction machines |
2014 |
2015 |
Change |
Bulldozer |
3,972 |
3,880 |
-2.3% |
Loader |
20,624 |
21,979 |
6.6% |
Forklift |
156,612 |
164,983 |
5.3% |
Excavator |
133,388 |
136,244 |
2.1% |
Crane |
9,410 |
9,758 |
3.7% |
Dump truck |
54,395 |
55,023 |
1.2% |
Concrete mixer truck |
23,179 |
23,785 |
2.6% |
Concrete pump |
5,816 |
6,370 |
9.5% |
Roller |
6,397 |
6,417 |
0.3% |
Air compressor |
4,333 |
4,546 |
4.9% |
Drilling rig |
4,820 |
5,013 |
4.0% |
Other |
7,148 |
7,724 |
8.1% |
Total |
430,094 |
445,722 |
3.6% |
*Source: Statistics on the state of construction machines, Ministry of Land, Infrastructure, and Transport
On the other hand, road transport emissions, which accounted for 8.9% of total emissions, decreased 4.4% (401 metric tons) compared to the previous year, due to a decrease of 23.5% (2014: 5.248 million km → 2015: 4.016 million km in the VKT of small passenger cars. In addition, emissions from energy production decreased by 2.0% (72 metric tons), which was due to a decrease in the use of combined-cycle power (2014: 111,711 Gwh → 2015: 100,598 Gwh).
Fig. 5.
Trends in TSP emissions, by emission source, in the last 5 years.
Table 7.
Trends in TSP emissions, by emission source, in the last 5 years.
(units: metric tons/year)
Source category |
2011 |
2012 |
2013 |
2014 |
2015 |
Change |
Energy production |
5,024 |
4,893 |
4,961 |
4,733 |
4,692 |
-0.9% |
Non industry |
2,562 |
2,398 |
2,289 |
1,908 |
1,841 |
-3.5% |
Manufacturing industry |
153,097 |
133,310 |
138,826 |
102,738 |
121,668 |
18.4% |
Industrial processes |
13,249 |
13,954 |
11,819 |
12,167 |
11,876 |
-2.4% |
Road transport |
13,030 |
12,969 |
12,103 |
10,019 |
9,583 |
-4.4% |
Non-road transport |
13,904 |
14,336 |
15,170 |
14,865 |
15,320 |
3.1% |
Waste |
334 |
456 |
330 |
335 |
340 |
1.4% |
Other |
609 |
428 |
488 |
428 |
498 |
16.5% |
Fugitive dust |
580,427 |
540,950 |
549,207 |
395,944 |
408,242 |
3.1% |
Biomass burning |
34,271 |
33,762 |
32,550 |
30,323 |
30,183 |
-0.5% |
Total |
816,508 |
757,456 |
767,743 |
573,460 |
604,243 |
5.4% |
Fig. 6.
Trends in PM10 emissions, by emission source, in the last 5 years.
Table 8.
Trends in PM10 emissions, by emission source, in the last 5 years.
(units: metric tons/year)
Source category |
2011 |
2012 |
2013 |
2014 |
2015 |
Change |
Energy production |
4,546 |
4,582 |
4,524 |
4,508 |
4,394 |
-2.5% |
Non industry |
2,213 |
2,062 |
1,955 |
1,629 |
1,582 |
-2.9% |
Manufacturing industry |
89,463 |
77,833 |
81,014 |
59,975 |
70,893 |
18.2% |
Industrial processes |
7,394 |
7,600 |
6,249 |
6,407 |
6,658 |
3.9% |
Road transport |
13,030 |
12,969 |
12,103 |
10,019 |
9,583 |
-4.4% |
Non-road transport |
13,901 |
14,332 |
15,167 |
14,861 |
15,317 |
3.1% |
Waste |
242 |
330 |
243 |
247 |
246 |
0.0% |
Other |
386 |
272 |
310 |
272 |
317 |
16.4% |
Fugitive dust |
113,267 |
115,121 |
108,942 |
98,671 |
109,633 |
11.1% |
Biomass burning |
17,016 |
16,702 |
15,663 |
14,583 |
14,552 |
-0.2% |
Total |
261,460 |
251,804 |
246,168 |
211,172 |
233,177 |
10.4% |
Fig. 7.
Trends in PM2.5 emissions, by emission source, in the last 5 years.
Table 9.
Trends in PM2.5 emissions, by emission source, in the last 5 years.
(units: metric tons/year)
Source category |
2011 |
2012 |
2013 |
2014 |
2015 |
Change |
Energy production |
3,534 |
3,660 |
3,573 |
3,679 |
3,607 |
-2.0% |
Non industry |
1,326 |
1,269 |
1,226 |
1,045 |
1,025 |
-1.9% |
Manufacturing industry |
45,721 |
39,700 |
41,606 |
30,322 |
36,317 |
19.8% |
Industrial processes |
5,876 |
6,032 |
4,829 |
4,903 |
5,132 |
4.7% |
Road transport |
11,988 |
11,932 |
11,135 |
9,218 |
8,817 |
-4.4% |
Non-road transport |
12,792 |
13,186 |
13,953 |
13,671 |
14,106 |
3.2% |
Waste |
209 |
265 |
202 |
204 |
209 |
2.8% |
Other |
348 |
244 |
279 |
245 |
285 |
16.4% |
Fugitive dust |
17,390 |
18,168 |
17,127 |
16,101 |
17,248 |
7.1% |
Biomass burning |
13,930 |
13,659 |
12,681 |
12,073 |
12,060 |
-0.1% |
Total |
113,114 |
108,114 |
106,610 |
91,460 |
98,806 |
8.0% |
Fig. 8.
Trends in BC emissions, by emission source, in the last 2 years.
Table 10.
Trends in BC emissions, by emission source, in the last 2 years.
(units: metric tons/year)
Source category |
2014 |
2015 |
Change |
Energy production |
324 |
307 |
-5.2% |
Non industry |
156 |
155 |
-0.9% |
Manufacturing industry |
648 |
741 |
14.2% |
Industrial processes |
15 |
16 |
4.9% |
Road transport |
5,674 |
5,456 |
-3.8% |
Non-road transport |
6,594 |
6,879 |
4.3% |
Waste |
3 |
3 |
2.8% |
Other |
11 |
15 |
27.7% |
Fugitive dust |
108 |
108 |
-0.3% |
Biomass burning |
2,261 |
2,255 |
-0.3% |
Total |
15,795 |
15,934 |
0.9% |
VOCs Emissions
The annual VOCs emission trend is shown in Fig. 9 and Table 11; the change in emissions resulted from changes in coating usage, and improvements in emissions lists and the emission factors. In 2015, emissions increased due to increases in the categories of waste and solvent use. Emissions from solvent use, which accounted for the largest portion of total emissions (54.9%), increased by 6,041 metric tons (1.1%) compared to the previous year; this was because of a 1.5% increase (5,089 metric tons) in emissions from painting facilities due to a 5.7% increase (2014: 240,252 kL → 2015: 253,912 kL) in supply of paints for construction and buildings (record of construction coatings supply). In non-road transport as well, there was an emissions increase of 9.3% (3,438 metric tons) compared to the previous year, which was found to be the result of an increase in the mean operating rate of construction machinery (2014: 40.71% → 2015: 41.55%). Emissions from industrial processes showed a 1.4% increase (2,548 metric tons) compared to the previous year. The increase in emissions in this category was due to a 4.5% increase (2014: 144.309 million kL → 2015: 150.862 million kL) in the crude oil input volume in the petroleum product manufacturing sector. The energy transport and storage category also showed an increase of 5.4% (1,492 metric tons) compared to the previous year; this was due to increases of 6.4% (2014: 22.774 million kL → 2015: 24.234 million kL) and 5.1% (2014: 11.464 million kL → 2015: 12.047 million kL), respectively, in the production and sales of gasoline.
Fig. 9.
Trends in VOCs emissions, by emission source, in the last 5 years.
Table 11.
Trends in VOCs emissions, by emission source, in the last 5 years.
(units: metric tons/year)
Source category |
2011 |
2012 |
2013 |
2014 |
2015 |
Change |
Energy production |
7,623 |
7,992 |
8,545 |
7,697 |
7,464 |
-3.0% |
Non industry |
2,948 |
2,953 |
2,784 |
2,558 |
2,622 |
2.5% |
Manufacturing industry |
3,560 |
3,373 |
3,537 |
3,280 |
3,101 |
-5.5% |
Industrial processes |
146,499 |
166,668 |
174,156 |
180,351 |
182,899 |
1.4% |
Energy transport and storage |
25,318 |
26,985 |
27,241 |
27,645 |
29,137 |
5.4% |
Solvent use |
559,662 |
565,495 |
562,070 |
549,318 |
555,359 |
1.1% |
Road transport |
69,059 |
67,776 |
65,807 |
49,468 |
46,145 |
-6.7% |
Non-road transport |
16,758 |
20,274 |
22,288 |
36,873 |
40,311 |
9.3% |
Waste |
40,879 |
49,257 |
46,508 |
48,061 |
57,074 |
18.8% |
Other |
803 |
549 |
637 |
551 |
648 |
17.5% |
Biomass burning |
106,153 |
104,930 |
101,487 |
86,454 |
86,012 |
-0.5% |
Total |
979,262 |
1,016,252 |
1,015,059 |
992,256 |
1,010,771 |
1.9% |
Moreover, road transport, which accounts for 4.6% of total emissions, has shown a continual decrease in VOCs emissions due to an increase in the number of recent cars being registered and improvements in emissions factors. Emissions from this category also decreased 6.7% (3,323 metric tons) in 2015 compared to the previous year, which was due to a 10.5% decrease (2014: 13.624 billion km → 2015: 12.195 billion km) in the VKT of small passenger cars.
NH3 Emissions
As Fig. 10 and Table 12 show, there was an overall increasing trend in NH3 emissions in 2015 compared to 2011, with a 4,666 metric ton increase in 2015 over the previous year. Agriculture (fertilizer use, livestock excrement, etc.), which is the main source of NH3 emissions, accounts for 77.8% of total NH3 emissions as of 2015, and emissions from this category increased 3,310 metric tons (1.5%) in 2015 compared to the previous year. There was an increase of 3,581 metric tons (1.7%) in emissions from excrement management, which influenced the increase in total emissions from this category. This was the result of a 5.6% increase (2014: 179.390 million animals → 2015: 189.417 million animals) in the number of livestock. In the industrial processes category, there was an increase of 3.7% (1,389 metric tons) in 2015 compared to the previous year; this was the result of a 4.5% increase (2014: 144.309 million kL → 2015: 150.862 million kL) in the crude oil input volume in the petroleum product manufacturing sector.
Fig. 10.
Trends in NH3 emissions, by emission source, in the last 5 years.
Table 12.
Trends in NH3 emissions, by emission source, in the last 5 years.
(units: metric tons/year)
Source category |
2011 |
2012 |
2013 |
2014 |
2015 |
Change |
Energy production |
1,465 |
1,586 |
1,745 |
1,425 |
1,379 |
-3.2% |
Non industry |
1,528 |
1,477 |
1,392 |
1,280 |
1,351 |
5.6% |
Manufacturing industry |
863 |
803 |
800 |
717 |
627 |
-12.5% |
Industrial processes |
33,530 |
38,006 |
35,051 |
38,043 |
39,432 |
3.7% |
Road transport |
9,208 |
9,641 |
9,839 |
10,113 |
10,078 |
-0.3% |
Non-road transport |
662 |
214 |
220 |
116 |
117 |
0.8% |
Waste |
23 |
24 |
23 |
23 |
22 |
-3.2% |
Agriculture |
216,453 |
238,975 |
231,117 |
227,953 |
231,263 |
1.5% |
Other |
12,684 |
12,737 |
12,785 |
12,832 |
12,882 |
0.4% |
Biomass burning |
20 |
20 |
20 |
16 |
15 |
-3.4% |
Total |
276,435 |
303,483 |
292,993 |
292,517 |
297,167 |
1.6% |
On the other hand, NH3 emissions from the manufacturing industry category showed a 12.5% decrease (90 metric tons) compared to the previous year. This decrease was due to a 31.9% decrease (2014: 4.694507 billion m3 → 2015: 3.196508 billion m3) in LNG usage in the “Other” subcategory of combustion (manufacturing industry) compared to the previous year.