nitrogen emissions from u.s. transportation...
TRANSCRIPT
Nitrogen Emissions from U.S. Transportation Sources
John Davies Office of Transportation and Air Quality U.S. EPAApril. 9, 2008
Overview
� Transportation Combustion emissions
�NOx
�N2O
� Relative significance of activity trends and emissions controls
� Factors affecting transportation fuel consumption and GHG emissions
� Relationship of NOx / N2O emissions controls to fuel consumption
U.S. NOX Emissions in 2005
Industrial processes, waste disposal & other
7%On-Road Vehicles
43%Stationary Fuel Combustion
38%
Nonroad Vehicles
Source: Inventory of U.S. Greenhouse 12% Gas Emissions and Sinks, 1990-2005
U.S. N2O Emissions in 2005
Other Sources 14%
On-Road VehiclesAgricultural and Soil 7%Management
78% Non-Road Mobile 0.8%
Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2005
1. 0%HFCs
95.1%
1. 0%HFCs
95.1%
Greenhouse Gas Emissions by Gas, 2005
HFCs, PFCs N2O HFCsN2O HFCs
CH4CH47.4%7.4%
CO2
95.1%
CH4 0.1%
7% 3.
CO2
85%
N2O 6.5% 2.2%
CO2
83.8% CO2CO2
95.1%
CH40.1%
7% 3.
CO2
85%
N2O6.5% 2.2%
CO2
83.8%CO2
& SF6 1.9% 3.3%
94.7.%
All U.S. Sources Transportation OnlyAll U.S. Sources Transportation Only
Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2005
Change in U.S. Vehicle Movement, 1990-2005
Population
GDP
Light-Duty Vehicles
Freight Trucks
Commercial Aircraft
+68.8%
Vehicle Miles Traveled +39%
Ton-Miles +58%
Passenger Miles Traveled
+19%
+55%
0% 10% 20% 30% 40% 50% 60% 70%
Sources: Highway Statistics 2006 Table VM-1, National Transportation Statistics 2005 Table 4-21
Change in U.S. Vehicle Movement, 1990-2005
Commercial Aircraft
Freight Trucks
Vehicles
+68.8%
GDP
-18.3%
Light-Duty Vehicle Miles Traveled +39%
Ton-Miles +58%
Passenger Miles Traveled
Population +19%
+55%
-37.6% On-Road + Air NOx
Road + Air N20
0% 10% 20% 30% 40% 50% 60% 70%
Sources: Highway Statistics 2006 Table VM-1, National Transportation Statistics 2005 Table 4-21 Inventory of U.S. GHG Emissions and Sinks
Factors Affecting Mobile N2O and NOX tailpipe emissions � Vehicle activity � Fuel consumption � Fuel characteristics � Air-Fuel mixes � Combustion temperatures � Emissions control equipment
Change in U.S. Vehicle Movement, 1990-2005
Commercial Aircraft
Freight Trucks
Vehicles
+68.8%
NOx
N2O
NOx
N2O
NOx
N2O
Light-Duty Vehicle Miles Traveled +39%
Ton-Miles +58%
Passenger Miles Traveled
-47%
-20.5%
-24%
+1%
+62%
+35.2%
0% 10% 20% 30% 40% 50% 60% 70%
Sources: Highway Statistics 2006 Table VM-1, National Transportation Statistics 2005 Table 4-21
EPA Tier O – B arl EPA Tier 1 – 1990
NOx TrendsU.S. NOx Emissions, 1970 - 2006
Millions of short tons
30.00
25.00
20.00 Other
15.00 Stationary FuelCombustion
10.00 Nonroad Vehicles
5.00 On-Road Vehicles
0.001970 1975 1980 1985 1990 1995 2000 2001 2002 2003 2004 2005 2006
egan e yOxidation Catalyst 1975 to 1980 (cars) 1980s; common until 1984 EPA Tier 2 - 2004
Added advanced emissions and 1980 to 1985 Implemented in cars and LD controls, including elec. Added more advanced
(trucks) trucks Controlled fuel injection & emissions controls, including
ignition timing, EGR and air improved combustion, 3-way catalyst; on-board
NOx reduced 90 percent from diagnostic computer and oxygen injection
sensor NOx reduced 60 percent from Tier 0
Reduced NOX to nitrogen and Tier 0 Nonroad Diesel oxygen; 1.0 g / mil for cars Diesel truck Rule
and bus Locomotive and standards Marine Rule
N2O Trends
600
500
Other400
300
Agricultural and Soil200 Management
100Nonoad MobileOn-Road Vehicles0
1990 1995 2000 2001 2002 2003 2004 2005
Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2005
Factors Affecting Mobile N2O and NOX tailpipe emissions � Fuel characteristics � Air-Fuel mixes � Combustion temperatures � Use of pollution control equipment � N2O in particular can be formed by
catalytic processes used to controlNOx, CO, and hydrocarbon emissions
Impact of Emissions Control Devices on Transportation N2O Emissions
Transportation GHG Emissions by Gas (Indexed to 1990)
0 0.2 0.4 0.6 0.8
1 1.2 1.4
CO2
N2O
CH4
1975 1980 1990 1992 1994 1996 1998 2000 2002 2004 2006
Oxidation EPA Tier O – EPA Tier 1 EPA Tier 2 – 2004 Catalyst 1975 to 1980 (cars) and 1980 to 1985 (trucks)
Increased per-mile N2O through NOx controls
Reduced N2O emissions rates, but still higher than non-catalyst systems
Reduced N2O emissions by 90 percent relative to Tier 1
Increased N2O emissions rate Rate = Rate =
Rate = 0.0036 g / mi
almost 3X 0.064 g / mi 0.0429 g / mi
Rate = 0.050 g / mile
Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2005
Total U.S. EmissionsShare of
U.S. Greenhouse Gas Emissions, Mobile Emissions Transportation 2005 (Tg CO2 Eq.) Sector GHGs
i
28% 2 Eq)
72% 2 Eq)
95.6 (Official Estimate)
632.9
566.7
ing 53.1
385.8
i191.8
Transportation Source GHGs Relative to
Source: Inventory of U.S. Greenhouse Gas Emiss ons and Sinks, 1990-2005
Transportation
(2014.0 Tg CO
Other Sectors
(5246.7 Tg CO
International Bunkers - Air and Marine Reported in Inventory, but not included in U.S. Total GHG Estimate or
Passenger Cars
Light-Duty Trucks
Mobile Air Condition
Freight Trucks
Commercial Aircraft 158.1
Buses and Motorcycles 17.1
Other Non-Road 176.2
Lubricants 10.2
Non-Transportation Mob le Sources
Refrigerated Transport 13.6
Included primarily in Industrial sector estimates
0.5% 8.7% 7.9% 0.7%
19.1%
0.8% 2.6%
59.5%
N/A
N/A Transportation Sector Estimate
U.S. Greenhouse Gas Emissions, 1990-2005, Transportation and other U.S. Sources
0
Transportation
Non-Transportation Mobile
Other U.S. Sources
129.1
191.8
6242.0
7260.4
1526.1 1496.0 1539.4 1592.6 1645.2 1680.3 1723.0 1750.4 1785.2 1852.2 1906.7 1879.8 1934.7 1932.5 1987.1 2014.2
1000
2000
3000
4000
5000
6000
7000
8000
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Absolute increase, 1990-2005 Percent Change, 1990-2005Transportation + 487.9 Tg CO2 Eq. Transportation +32.0%
Non-Trans Mobile +62.7 Tg Co2 Eq. Non-Trans Mobile +48.6%
All other sources + 467.8 Tg CO2 Eq. All other sources + 10.2%
Total +1018.4 Tg CO2 Eq. Total (including transport) +16.3% Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2005
Impact of U.S. Fuel Consumption since 1990
US CO2 Emissions from Fossil Fuel Combustion 6000
5000
4000
3000
2000
1000
0
Other U.S. Sources
Non-Transportation Mobile
Transportation
1990 1995 2000 2001 2002 2003 2004 2005
Absolute increase, 1990-2005 Percent Change, 1990-2005 Transportation + 431.9 Tg Transportation +29.4%
Non-Trans Mobile + 62.1 Tg Non-Trans Mobile +48.6%
All other sources + 534.1 Tg All other sources + 11.2%
Total +1027.1 Tg Total (including transport) +21.7%
Per Capita CO2 Emissions from Fossil Fuel Combustion, 1990 and 2005
1990
2005
0 10000 20000 30000 40000 50000
Transportation Other U.S. Sectors
12,956 lbs
14,112 lbs
27,634 lbs
27,237 lbs
41,720lbs
42,762 lbs
1,13
0 lb
s
1,41
2.7
lbs
Non-Trans Mobile
Sources: Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2005
U.S. Census Bureau, Population Division
U.S. GHG Emissions by Gas All Sources 1990 and 2005
6089.5 6000
5000
4000
3000
2000
1000
0
5061.6 1990
2005
609.1 539.3 482.0 468.6 163.089.3
CO2 CH4 N2O HFCs. PFCs and SF6
U.S. Transportation GHG Emissions by Gas, 1990 and 2005
1478.8
1908.1
36.5 67.142.7
0
1000
2000
3000
4000
5000
6000 1990
2005
4.5 N/A 2.3
CO2 CH4 N2O HFCs. (Reflects the phase-in HFCs for ozone-deleting substances)
US Transportation GHGs by Major Source, 1990 and 2005
1199.6 1200
1000
800
600
400
200
0
Light-Duty Freight Trucks Commercial Other * Vehicles Aricraft
1990
2005
69.4%
972.6
227.7 188.1
385.8
158.1
270.5
137.7 14.8%
23.3%
*Other GHGs include emissions from HFCs, which were introduced beginning in the early 1990s to replace ozone depleting substances; increase from 1990 is not meaningful.
Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2005
Change in Vehicle Movement, 1990-2005
Light-Duty Vehicles
Freight Trucks
Commercial Aircraft
0% 10% 20% 30% 40% 50% 60% 70%
+68.8%
Vehicle Miles Traveled +39%
Vehicle Miles +52%
Passenger Miles Traveled
Sources: Highway Statistics 2006 Table VM-1, National Transportation Statistics 2005 Table 4-21
Change in Activity, Intensity and GHGs, 1990-2005(Passenger Miles and Ton-Miles)
Light-Duty Vehicles
Freight Trucks
Commercial Aircraft
+23.3%
GHGs +69.4%
+14.8%
GHGs /
-10.2% GHGs /PMT
-32.0% GHGs /
PMT
Passenger Miles Traveled +37%
GHGs
Ton-Miles +58%
Passenger Miles Traveled +68.8%
GHGs
ton-mile +7.3%
0% 10% 20% 30% 40% 50% 60% 70%
Sources: Highway Statistics 2006 Table VM-1, National Transportation Statistics 2005 Table 4-21
Light-Duty Vehicles
1990-2005� GHGs up 23.3%; annualized
increase of 1.3% � Passenger Car GHGs decreased
by just under 2% � LD Truck GHGs increased by 72% � Total VMT up 38 percent (mainly
light-duty truck)
2004-2005� GHGs declined very slightly
(0.04%) � Likely impact of fuel prices � Passenger Car GHGs decreased
for the third year in a row � LD Truck GHGs up 2.7 percent,
below avg. annual increase of 3.7 percent from 1990 to 2004
Sources: Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2005; Highway Statistics 2005
Tg C
O2
Eq.
GHGs from Light-Duty Vehicles, 1990-2005 800
Passenger Cars 700
600
500 Light-Duty Trucks 400
300
200
100
0 1990 1995 2000 2005
3,000,000
2,500,000
2,000,000
1,500,000
1,000,000
500,000
0
Up 84.4%
Passenger Car VMT
Up 19.2%1,417,823
1,689,965
574,571
1,059,590 Light-Duty Truck VMT
1990 2005
All Light-Duty Vehicles
Light-Duty Vehicles
Sales-Weighted Fuel Economy for New Light-Duty Vehicles and Total LD Fleet, 1975 - 2005
8
4
0 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005
12
16
leet
New Vehicles 22.1 mpg 21.0 mpg
19.7 mpg
15.1 mpg
13.5 mpg
18.9 mpg
Total LD F
Model Year
Sales of New Light-Duty Vehicles, 1975 - 2005
24
20
Mile
s pe
r Gal
lon
12000
10000
8000
6000
4000 Li
Passenger Cars
7,976
ght-Duty Trucks
7,992
Source: Light-Duty Automotive and Fuel
0
2000
Economy Trends: 1975 through 1975 1980 1985 1990 1995 2000 2005 2006, U.S. EPA
Commercial AircraftPercent Change in Aircraft PMT and GHG Emissions, 1990-2005
Perc
enta
ge o
f Ava
ilabl
e Se
ats
Occ
upie
d
80%
Aircraft Passenger Miles
Aircraft GHGs
1990-2005 60%
� GHGs increased 14.8 percent40%
� Passenger miles increased 68 20% percent
� GHGs per passenger mile 0% decreased by 32 percent
-20% � Increased passenger loads1990 1995 2000 2005 � Increased fuel efficiency of
62
7771
60.4 61.2 62.4 64.7 65.4 67.9 69.1 69.9 69.8 69.1 70.3 74.4 72.6
Commercial Aircraft Passenger Load Factor, 1990-2005 new aircraft (~2 percent annually)
80
60 2004-2005 � GHGs increased 6.4 percent
40 � Indicate that we’re approaching a
passenger load ceiling?20
0
1990 1995 2000 2005
Sources: Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2005; National Transportation Statistics 2005
Freight Trucks
� GHGs increased 69.4 percent (3.6 percent annualized)
� Medium- and havy-duty trucks have become less energy efficient since the mid-1990s (VIUS data) � Fuel economy of medium trucks (10,000 to 26,000 lbs)
decreased from 8.6 MPG in 1997 to 8.0 mpg in 2002 � FE of heavy trucks (over 26,000 lbs) decreased from 6.1
MPG in 1997 to 5.8 MPG in 2002 � Possible explanations for decreased fuel economy
� Demand for more powerful engines � Impact of congestion � Elimination of mandatory speed limits
GH
G E
mis
sion
s (T
g CO
2 eq
uiv.
)
Freight SourcesGHG Emissions, 1990-2005 Ton-Miles, 1990-2004
450 Trucking
Water
Rail
Pipeline
Air
1,800,000
400 1,600,000
350 1,400,000
300 1,200,000 250
1,000,000 200 800,000 150
600,000 100
400,000 50
200,000 0
0 1990 1995 2000 2005
1990 1992 1994 1996 1998 2000 2002 2004
Sources: Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2005; National Transportation Statistics 2005
Air Rail
Change in Freight Activity, Energy Efficiency and GHGs by Mode, 1990 to 2005
85%
75%
65%
55%
45%
35%
25%
15%
5%
-5%
-15%Air Rail Trucking Pipeline
)
ity i ions
ici
Vari
atio
n be
twee
n 19
90 a
nd 2
005
(%
ActivEm ssEnergy Eff ency
Sources: Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2005; National Transportation Statistics 2005
Additional Information
Greenhouse Gas Emissions from Transportation and other Mobile Sources http://www.epa.gov/climatechange/emissions/usinventoryreport.html
Inventory of U.S. Greenhouse Gas Emissions and Sinks http://www.epa.gov/climatechange/ emissions/usinventoryreport.html