May 18, 2012
Projection of the CARB 2008 Emissions Inventory for
Northern Mexico to Future Years
INTRODUCTION
In ERG (2009), the baseline 1999 national emissions inventory for Mexico was projected to the years 2008, 2012, and 2030. These projections were used to extrapolate the year 2008 emissions inventory for Baja California (CARB, 2012) to the years 2023 and 2030 for air quality analyses within southern California.
In their analyses, ERG (2009) used projections of population growth, industrial development, and land use planning to estimate future emissions; in many cases, by individual source classification code (SCC). However, this level of detail is beyond the scope of what can be done in the short term. Also, while the emissions inventory generated for Baja California by the CARB (2012) used ERG’s year 2008 inventory as a starting point, the final inventory was appreciably different. In this analysis, the relative changes in emissions growth quantified by ERG for the years 1999, 2008, and 2030 were used to prepare emissions-response curves, which were then used to scale the CARB 2008 inventory to future years.
PREPARATION OF EMISSIONS RESPONSE FUNCTIONS
The emissions inventories developed by ERG (2009) for the years 1999, 2008, 2012, and 2030 were provided in four broadly defined groups: on-road, non-road, point, and non-point emissions. Within these groups, emissions for CO, NOx, SOx, COT (VOC), PM10 (PM), and NH3 were provided by State and by Municipality. To avoid being confounded by differences in spatial distributions and source classifications, emissions within each group were summed by State and Municipality. The emissions totals were used to develop a relative response function for each chemical species category using a second-order polynomial as a function of time. In Table 1, the resulting non-road mobile source emissions factors are summarized.
For some emissions groups, the year 2012 appeared to be something of an aberration in the projections. For example, non-point source CO emissions for Tijuana (Table 3; Municipality 4 -- see also Figure 4) are projected to decline approximately 30% (from 24.1 to 13.6 ton/day) in the 4-year period between 2008 and 2012. Similarly, - 1 -
VOC emissions for Mexicali (Table 3; Municipality 2 -- see also Figure 2) are projected to decline approximately 30% in the same period. It is unclear why this should be; it may be an artifact from the balance of emissions controls and growth, or it may be due to some subtle differences in data file formats. In either case, because of this apparent aberration, year 2012 was not used to develop the growth-response curves for this analysis (see Figure 1). Response functions for selected emissions groups and municipalities are shown in Figures 1-5.
Three scenarios were used by ERG (2009) to project on-road mobile source emissions into future years. The first (CM1) was based on the assumption that mobile- source emissions would be influenced primarily by changes in fuel economy. The second (CM2) was based on the assumption that mobile source emissions would be influenced by increased use of oxygenated fuels. The third (CM3) was based on the assumption of a combination of scenarios CM1 and CM2. Since oxygenation of fuels would likely be accompanied by changes in VOC emissions profiles, only the CM1 scenario was processed.
EMISSIONS PROJECTIONS OF THE CARB INVENTORY
The CARB 2008 (CARB, 2012) emissions inventory for Baja California was prepared from 3 sources. The first was the Year 2008 emissions inventory based on the projections of ERG (2009). The second and third were based on special projects by ERG (2008) and LTC (2010) for Mexicali and Tijuana and Rosarito, respectively. Therefore, the grouping of based of on-road, non-road, point, and non-point emissions for the municipalities of Ensenada and Tecate were consistent with the ERG (2009) projections. However, because of the more varied and detailed datasets gathered for Mexicali and Tijuana and Rosarito it was not always apparent which of the response functions were most appropriate for each dataset component. After consideration, the emissions categories for Mexicali and for Tijuana and Playa de Rosarito assigned scale functions are summarized in Table 5. Emissions of road dust were assumed to not change between 2008 and 2030.
In Table 6, the year 2008 emissions inventory for Mexicali (from CARB, 2012) is summarized and projections for the years 2023 and 2030 are summarized in Tables 7, and 8, respectively. Within the period between 2008 and 2030, CO emissions are projected to decline and then increase, NOx emissions are projected to increase, and PM and VOC emissions are projected to increase but only within a range of approximately 10%.
In Table 9, the year 2008 emissions inventory for Tijuana and Playa De Rosarito (from CARB, 2012) are summarized and projections for the years 2023 and 2030 are
- 2 - summarized in Tables 10 and 11, respectively. Within the period between 2008 and 2030, the pattern of CO and NOx emissions is similar to that of Mexicali. However, in contrast to Mexicali, PM and VOC emissions for Tijuana and Playa DE Rosarito are projected to increase over the period; with the greatest increases attributed to elevated point source emissions.
The combined projected emissions for Baja California are summarized for the year 2023 in Table 12, and for the year 2030 in Table 13.
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Table 1. On-road mobile source emissions for Baja California, by municipality, projected from the year 1999 to 2008, 2012, and 2030 by ERG (2000).
Mun. CO NH3 NOx PM10 PM25 SOx VOC
Year 1999 1 37.6 0.1 4.1 0.2 0.2 0.2 4.9 2 101.3 0.2 11.0 0.5 0.5 0.6 13.1 3 4.3 0.0 0.5 0.0 0.0 0.0 0.6 4 225.0 0.4 24.1 1.1 1.1 1.4 29.5 5 3.4 0.0 0.4 0.0 0.0 0.0 0.5
Year 2008 1 23.9 0.2 3.4 0.3 0.3 0.2 3.5 2 64.3 0.3 9.3 0.8 0.7 0.5 9.4 3 2.7 0.0 0.4 0.0 0.0 0.0 0.4 4 142.7 0.6 20.4 1.8 1.6 1.1 21.2 5 2.2 0.0 0.3 0.0 0.0 0.0 0.3
Year 2012 1 16.8 0.2 3.1 0.3 0.3 0.0 3.0 2 45.3 0.4 8.4 0.9 0.8 0.1 7.9 3 1.9 0.0 0.3 0.0 0.0 0.0 0.3 4 100.6 0.8 18.5 1.9 1.7 0.1 17.8 5 1.5 0.0 0.3 0.0 0.0 0.0 0.3
Year 2030 1 22.8 0.5 1.1 0.7 0.6 0.1 2.7 2 61.5 1.0 2.9 1.7 1.6 0.1 7.1 3 2.6 0.0 0.1 0.1 0.1 0.0 0.3 4 136.6 1.9 6.4 3.8 3.4 0.3 16.1 5 2.1 0.0 0.1 0.1 0.1 0.0 0.3
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Table 2. Non-road mobile source emissions for Baja California, by municipality, projected from the year 1999 to 2008, 2012, and 2030 by ERG (2000).
Mun. CO NH3 NOx PM10 PM25 SOx VOC
Year 1999 1 2.4 0.0 4.6 0.6 0.5 0.1 0.5 2 6.0 0.0 10.8 1.4 1.3 0.1 1.3 3 0.4 0.0 0.8 0.1 0.1 0.0 0.1 4 6.1 0.0 2.1 1.4 1.3 0.2 1.3 5 0.3 0.0 0.6 0.1 0.1 0.0 0.1
Year 2008 1 2.5 0.0 4.6 0.6 0.6 0.1 0.5 2 6.2 0.0 11.1 1.5 1.4 0.1 1.4 3 0.4 0.0 0.8 0.1 0.1 0.0 0.1 4 6.0 0.0 1.8 1.3 1.3 0.2 1.2 5 0.3 0.0 0.6 0.1 0.1 0.0 0.1
Year 2012 1 2.6 0.0 4.8 0.6 0.6 0.1 0.6 2 6.5 0.0 11.6 1.5 1.5 0.2 1.5 3 0.4 0.0 0.8 0.1 0.1 0.0 0.1 4 6.2 0.0 2.4 1.4 1.4 0.2 1.3 5 0.3 0.0 0.6 0.1 0.1 0.0 0.1
Year 2030 1 4.0 0.0 7.3 0.9 0.9 0.1 0.9 2 9.8 0.0 7.5 2.3 2.2 0.2 2.2 3 0.6 0.0 1.3 0.1 0.1 0.0 0.1 4 9.6 0.0 9.2 2.2 2.1 0.3 2.0 5 0.5 0.0 1.0 0.1 0.1 0.0 0.1
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Table 3. Non-point source emissions for Baja California, by municipality, projected from the year 1999 to 2008, 2012, and 2030 by ERG (2000).
Mun. CO NH3 NOx PM10 PM25 SOx VOC
Year 1999 1 12.2 10.9 6.9 2.2 1.6 4.9 19.9 2 27.4 16.2 6.0 6.6 4.4 2.8 47.8 3 2.9 0.3 0.9 0.3 0.3 2.1 5.8 4 16.9 3.0 11.5 3.7 2.5 11.0 35.9 5 1.3 0.2 3.1 0.2 0.2 0.4 5.6
Year 2008 1 21.4 6.4 11.1 3.1 2.3 3.6 26.7 2 13.4 16.8 7.6 8.4 5.4 9.5 42.1 3 6.1 0.3 1.2 0.6 0.5 1.6 8.1 4 24.1 3.8 14.0 4.0 2.8 3.5 50.2 5 2.3 0.3 3.8 0.2 0.2 0.2 7.8
Year 2012 1 14.0 6.5 5.0 3.2 2.3 1.8 30.2 2 9.0 17.0 8.4 8.2 5.2 4.5 29.5 3 6.6 0.4 1.3 0.6 0.5 0.8 9.3 4 13.6 4.3 15.0 3.6 2.5 1.2 53.9 5 2.8 0.3 4.6 0.3 0.2 0.1 9.3
Year 2030 1 19.0 7.1 11.6 4.2 3.2 1.1 50.5 2 18.7 17.9 7.1 8.5 5.4 1.3 46.5 3 11.7 0.7 2.2 0.6 0.5 0.2 15.8 4 25.1 6.7 19.8 4.7 3.3 3.1 57.2 5 7.3 0.7 1.5 0.5 0.5 0.1 11.0
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Table 4. Elevated point source emissions for Baja California, by municipality, projected from the year 1999 to 2008, 2012, and 2030 by ERG (2000).
Year 1999 Mun. CO NH3 NOx PM10 PM25 SOx VOC
Year 1999 1 0.0 0.0 0.1 2.5 1.5 0.7 24.9 2 0.3 0.0 3.2 6.5 5.1 5.5 4.1 3 0.0 0.0 0.0 0.0 0.0 0.0 0.1 4 0.6 0.0 3.3 0.3 0.2 2.3 20.8 5 1.4 0.0 10.6 4.9 4.8 71.7 0.5
Year 2008 1 0.0 0.0 0.1 3.4 2.0 1.0 33.8 2 0.4 0.0 4.6 8.9 7.0 7.7 5.6 3 0.0 0.0 0.0 0.0 0.0 0.0 0.1 4 0.8 0.0 2.4 0.3 0.2 2.0 28.2 5 3.2 0.0 23.6 2.1 2.1 31.2 0.4
Year 2012 1 0.0 0.0 0.1 3.9 2.3 1.2 38.5 2 0.5 0.0 5.4 10.2 8.0 8.9 6.4 3 0.0 0.0 0.0 0.0 0.0 0.0 0.1 4 1.0 0.0 2.4 0.4 0.3 2.1 32.4 5 4.2 0.0 30.6 1.5 1.4 21.4 0.4
Year 2030 1 0.0 0.0 0.2 7.2 4.3 2.1 68.7 2 0.9 0.0 10.7 19.0 14.9 16.9 11.7 3 0.0 0.0 0.1 0.0 0.0 0.0 0.1 4 1.8 0.0 3.4 0.7 0.5 3.3 60.0 5 11.1 0.0 81.6 0.6 0.6 9.5 0.3
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Table 5. Response function assignments for emissions groups within the Mexicali, and the Tijuana and Playa de Rosarito municipalities.
Emissions Group Projection Function
Mexicali
Urban Area Non-Point Non-Point /1 Non-Point Agriculture Non-Point
On-road Mobile On-Road Road Dust (not scaled) Railroad Non-Road
Federal Point Point State Point Non-Point
Tijuana/Rosarito
Agric/Construction Non-Point Urban Area Non-Point Airports/Borders Non-Point Surface Point Non-Point On-road mobile On-Road Road dust (not scaled) Point Sources Point
1/ For Mexicali, ‘non-point’ emissions refers to border crossings, airports, brick kilns, animal feedlots, and waste-water treatment.
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Table 6. Combined emissions (ton/day) for the municipality Mexicali on a summer weekday for the year 2008.
CO NOx SOx TOG PM NH3
Urban Area 4.8 10.4 0.3 32.8 2.9 0.0 Non-Point 3.8 0.2 2.3 2.1 2.9 8.9 Agriculture 48.8 4.9 0.4 4.1 9.6 16.4
On_Road Mob. (sum/wd) 186.2 23.4 0.7 31.0 2.3 0.8 Road Dust (wd) 0.0 0.0 0.0 0.0 107.8 0.0 Railroad 6.6 12.3 0.2 1.5 1.5 0.0
Federal Point 10.0 38.1 10.0 0.3 4.2 0.0 State Point 0.5 0.5 0.0 0.0 0.0 0.0
Summer/WD Totals 260.7 88.9 17.7 71.4 131.2 26.1
ERG (2008) Totals: 235.6 78.9 13.7 68.1 147.4 25.4
Table 7. Projected combined emissions (ton/day) for the municipality of Mexicali on a summer weekday for the year 2023.
CO NOx SOx TOG PM NH3
Urban Area 3.9 10.9 0.2 33.0 1.8 0.0 Non-Point 3.1 0.2 1.9 2.1 3.1 9.3 Agriculture 40.6 5.1 0.3 4.1 10.4 17.2
On_Road Mob. (sum/wd) 141.6 15.0 0.3 22.3 4.0 1.8 Road Dust (wd) 0.0 0.0 0.0 0.0 107.8 0.0 Railroad 8.8 10.3 0.3 1.9 2.0 0.0
Federal Point 17.5 69.1 17.4 0.6 7.2 0.0 State Point 0.5 0.5 0.0 0.0 0.0 0.0
Summer/WD Totals 215.9 111.1 20.3 64.1 136.3 28.2
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Table 8. Projected combined emissions (ton/day) for the municipality of Mexicali on a summer weekday for the year 2030.
CO NOx SOx TOG PM NH3
Urban Area 6.6 9.8 0.0 36.3 1.6 0.0 Non-Point 5.3 0.2 0.3 2.3 2.9 9.5 Agriculture 69.5 4.6 0.1 4.5 9.7 17.5
On_Road Mob. (sum/wd) 178.1 8.2 0.1 23.4 4.9 2.5 Road Dust (wd) 0.0 0.0 0.0 0.0 107.8 0.0 Railroad 10.5 8.3 0.3 2.3 2.3 0.0
Federal Point 22.4 88.6 21.9 0.7 9.0 0.0 State Point 0.5 0.5 0.0 0.0 0.0 0.0
Summer/WD Totals 292.9 120.2 22.8 69.5 138.1 29.4
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Table 9. Combined emissions (ton/day) for the municipalities of Tijuana and Playa de Rosarito for 2008.
CO NOx SOx TOG PM NH3
Agric/Construction 6.1 12.1 0.0 1.3 1.4 0.0 Urban Area 2.1 0.5 0.0 40.9 62.7 3.1 Airports/Borders 3.1 0.9 0.0 0.7 0.0 0.0 Surface Point 0.6 1.2 2.8 0.0 0.0 0.0 On-road mobile 192.7 31.3 0.8 20.1 0.4 0.9 Road dust 0.0 0.0 0.0 0.0 62.5 0.0 Point Sources 4.0 26.0 33.3 28.6 2.4 0.0
Totals 207.9 72.0 36.9 91.6 129.4 4.0
Table 10. Projected combined emissions (ton/day) for the municipalities of Tijuana and Playa de Rosarito for the year 2023.
CO NOx SOx TOG PM NH3
Agric/Construction 6.0 12.1 0.0 1.3 1.4 0.0 Urban Area 2.4 0.6 0.0 48.3 70.3 4.5 Airports/Borders 3.5 1.0 0.0 0.8 0.0 0.0 Surface Point 0.7 1.6 0.4 0.0 0.1 0.0 On-road mobile 146.6 17.8 0.4 14.6 0.6 2.0 Road dust 0.0 0.0 0.0 0.0 62.5 0.0 Point Sources 9.6 62.1 7.1 48.2 1.5 0.0
Totals 168.8 95.2 7.9 113.2 136.4 6.5
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Table 11. Projected combined emissions (ton/day) for the municipalities of Tijuana and Playa de Rosarito for the year 2030.
CO NOx SOx TOG PM NH3
Agric/Construction 6.3 17.2 0.0 1.4 1.6 0.0 Urban Area 2.2 0.7 0.0 46.6 73.7 5.4 Airports/Borders 3.2 1.1 0.0 0.8 0.0 0.0 Surface Point 0.7 1.8 2.5 0.0 0.1 0.0 On-road mobile 184.5 9.8 0.2 15.2 0.8 2.8 Road dust 0.0 0.0 0.0 0.0 62.5 0.0 Point Sources 13.1 85.3 12.9 60.5 2.5 0.0
Totals 210.0 115.9 15.6 124.5 141.2 8.2
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Table 12. Combined Baja California emissions (ton/day) for a summer week day in the year 2023
CO NOx SOx TOG PM NH3
Surface Ensenada 52.7 22.3 1.9 48.2 5.2 5.2 Mexicali 197.9 41.5 3.0 63.5 124.0 28.2 Tecate 15.4 3.6 0.7 13.8 0.9 0.6 Tijuana/Rosarito 159.3 33.2 0.8 64.9 134.9 6.6
Surface Totals 425.3 100.6 6.4 190.4 264.9 40.6
Elevated Point Ensenada 0.2 0.1 1.7 55.7 9.1 0.0 Mexicali 17.5 69.1 17.4 0.6 7.2 0.0 Tecate 0.1 0.0 0.0 0.1 0.0 0.0 Tijuana/Rosarito 9.6 61.9 7.1 48.2 1.5 0.0
Elevated Totals 27.1 131.2 26.2 104.5 17.8 0.0
Table 13. Combined Baja California emissions (ton/day) for a summer week day in the year 2030
CO NOx SOx TOG PM NH3 Surface Ensenada 42.4 20.0 1.2 58.2 5.5 7.3 Mexicali 270.0 31.0 0.9 68.8 124.1 29.4 Tecate 17.6 4.3 0.2 16.7 0.7 0.8 Tijuana/Rosarito 169.9 30.6 2.7 64.0 139.7 8.2
Surface Totals 529.6 85.8 5.0 207.8 269.0 45.7
Elevated Point Ensenada 0.0 0.2 2.1 68.9 11.4 0.0 Mexicali 22.4 88.6 21.9 0.7 9.0 0.0 Tecate 0.0 0.0 0.o 0.1 0.0 0.0 Tijuana/Rosarito 13.1 85.3 12.9 60.4 2.5 0.0
Elevated Totals 35.5 174.1 36.9 130.1 23.0 0.0
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Figure 1. Growth response functions between 1999 and 2030 for CO (a), NOx (b), VOC (c), and PM (d) emissions from on-road sources within the Tijuana municipality of Baja California.
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Figure 2. Growth response functions between 1999 and 2030 for CO (a), NOx (b), VOC (c), and PM (d) emissions from non-point sources within the Mexicali municipality of Baja California.
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Figure 3. Growth response functions between 1999 and 2030 for CO (a), NOx (b), VOC (c), and PM (d) emissions from on-road sources within the Mexicali municipality of Baja California.
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Figure 4. Growth response functions between 1999 and 2030 for CO (a), NOx (b), VOC (c), and PM (d) emissions from non-point sources within the Tijuana municipality of Baja California.
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Figure 5. Growth response functions between 1999 and 2030 for CO (a), NOx (b), VOC (c), and PM (d) emissions from elevated point sources within the Playa de Rosarito municipality of Baja California.
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References
1. ERG. 2009. Development of the Mexicao National Emissions Inventory Projections for 2008, 2012, and 2030. ERG Report No. 3667.00.001.001. January, 2009.
2. ERG. 2005. 2005 Mexicali Emissions Inventory – Draft Final Report. Eastern Research Group Project No: 3657.00.0004.001. October, 2008.
3. TLC.2010a. Tijuana and Playas De Rosarito Municipalities Emissions Inventory -- Draft Final Report. TL Consulting. Tijuana, Mexico. July, 2010.
4. USEPA. 2012 North American Emissions Inventory – Mexico. WEB site: http://www.epa.gov/ttnchie1/net/mexico.html
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