Challenges and opportunities of reducing aviation GHG emissions through policy and technology innovation

1. The Looming Challenges of Aviation
Greenhouse Gas (GHG) Reduction
Jawad Rachami, Liming Zhou, Royce Bassarab
Wyle Laboratories, Arlington, VA, 22202
AIAA ATIO / ANERS 2009
Hilton Head, SC
September 20, 2009

2. Million Metric Tons of Carbon Dioxide
USA
EU27
China
Russia
India
Japan
Airport GHG in Perspective
• The U.S. is the largest emitter of
GHG per Capita
• Transportation is responsible for
about 1/3 of energy-based US GHG
emissions
• Aircraft are estimated to contribute
less than 3% of total US GHG
emissions
• Modern airports are major
commercial and trade hubs with
various end-user GHG sources

3. Aviation GHG in Perspective
• Daily consumption of Jet fuel has
remained relatively stable in the
past 10 years given:
– 34% increase in total miles flown
– 20% increase in enplanements
– 32% increase in total commercial
operations
• Increased demand exerts pressure
on airports to expand facilities,
hence, increased energy use and
GHG emissions
U.S. Jet Fuel Daily Consumption
(Thousands of Barrels per Day)
U.S. Enplanements (Millions)
Total Miles Flown (Billions)
8
7
6
5
Less than 1% change over 20 yrs

4. Coping with a rapidly evolving environment…
New
Technology
New
Regulations
Advances
in Science

5. Evolving Regulatory Environment
• Internationally, the driving force behind the control of GHG emissions has
been the Kyoto Protocol
– Protocol now ratified by 183 countries and the European Union
– US has not ratified the Protocol
• Expansion of EU Emissions Trading Scheme (ETS) to include airlines
operating to and from the EU starting in 2012
• In US, EPA recently made the determination that CO2 and other GHGs pose
a danger to the public's health and welfare

6. Carbon Markets
• Two Markets: Mandatory and
Voluntary
– Mandatory markets: Kyoto Protocol's
Clean Development Mechanism and
European Union Emission Trading
Scheme (EU ETS)
– Voluntary Markets in US, Australia,
Japan
• EU ETS allows import of emissions
reductions via Joint Implementation
(JI) and Clean Development
Mechanism (CDM) projects
• Mandatory markets valued at $64
billion in 2007

7. Carbon Markets
• More than 400 million metric tons of
CO2 are exchanged through projects
annually
• Voluntary carbon market is a small
part of all carbon buying and trading:
$331M in 2007

8. Evolving Regulatory Framework:
Climate Change Legislation
• Climate Change Bill (Waxman-Markey):
– Proposal includes airlines in Cap & Trade
– GHG emissions stringency requirements for aircraft
sources
– Airports not mentioned – EPA likely to regulate under
stationary sources
• May redefine/clarify required scope/boundary of GHG
inventories
New
Technology
New
Regulations
Advances
in Science

9. Evolving Science:
Beyond the Kyoto Six
• Aviation produces emissions and climate-forcing effects in
UT/LS, including PM (incl., Sulfate, Elemental Carbon), ozone,
contrail and cirrus.
• Unlike CO2, these species are not as stable and have local
impacts. There is also higher uncertainty associated with
their global warming effect.
• ACCRI seeks to address a number of research gaps, including:
– Assessment of NOx, H2O, and PM impacts on climate forcing at
high altitude
– Defining a unified metric to quantify the effects of ozone,
contrails/cirrus, and PM
New
Technology
New
Regulations
Advances
in Science

10. Evolving Technology: Advanced Vehicles
Criteria / Technology
N+1 Generation:
Conventional Tube
& Wing (2010)
N+2 Generation:
Unconventional
Hybrid Wing Body
(2020)
N+3 Generation
(2030-2035)
Noise (Cumulative
below Stage 4)
- 32 dB - 42 dB
Better than - 71 dB (55
LDN at average
airport boundary)
LTO NOx Emissions
(below CAEP 2)
-70% -80%
Better than -80% plus
mitigate
formation of
contrails
Performance:
Aircraft Fuel
Burn
-33% -50%
Better than -70% plus
non-fossil fuel
sources
Performance: Field
Length
-33% -50%
Exploit metroplex
concepts
Source: Adapted from NASA Overview of NRA solicitation (N+3 Pre-Proposal Conference)

11. Evolving Technology:
Alternative Fuels
• New biofuel processing techniques (e.g., hydrogenation) are
producing viable biofuel alternatives/tracks for aviation.
• We are on the eve of another major technical breakthrough
(Algal-based fuel) following the breakthrough of deriving
alcohol from cellulosic mass.
• A major challenge is overcoming biomass source constraints
(e.g., land-use, production scale-up).
• CAAFI is considering a number of issues, including:
– Standards for aviation biofuels/blends
– LCA Methodologies for assessment of GHG reductions through
biofuels
New
Technology
New
Regulations
Advances
in Science

12. Airport GHGs: Not Just Aircraft

13. Modern Airport Cities
• The modern airport has evolved into a complex
regional economic engine– DFW example:
– More than 60% of DFW’s revenues are non-aeronautical
– Airport is a producer of natural gas and has major
industrial and commercial parks
• NextGen operational concepts such as Super Density
operations and surface optimization are an important
consideration for GHG mitigation
• Airports may become producers of biofuels through
onsite bio-refineries

14. Airport GHG Sources
AAiirrppoorrtt OOwwnneedd SSoouurrcceess
Typically NOT
Airport Owned Sources
• Buildings/Stationary Sources
– Electrical consumption
– Natural gas /oil combustion
– Fugitive refrigerant emissions
– Recycling/waste
• Service Vehicles/Fleet Vehicles
• Airfield/Runways/Taxiways
• Roadways
• Aircraft
• Auxiliary Power Units (APU)
• Ground Support Equipment (GSE)
• Tenant Stationary Sources
• Tenant Utilities (tenant receives bills)
• Roadways
• Ground Access Vehicles (GAV)
Note: Unique conditions for each airport should be confirmed

15. Ownership/Control Boundaries
• Boundaries set based on entity being inventoried:
– State Owned Airports
– City/County Owned Airport
– Airport Authority/Port Districts
– Privatized Airport (typically by city/county owned)
• Important to understand organization and it’s unique features:
– Some city/county owned airports have other departments that perform some airport
functions (police, fire, vehicle maintenance, etc.)
– Unique industrial tenant activities at some airports (farming, mining, drilling, military, etc.)

16. Airport GHG inventories:
Ownership/Control Boundaries
World Resource Institute (WRI) terms
0 Scope 1: Direct emissions from sources owned and controlled
* Airport-owned GSE/Fleet Vehicles
* Stationary Sources
0 Scope 2: Emissions from the generation of purchased electricity
* Electrical consumption for bills coming to airport operator
0 Scope 3: Emissions from sources not owned or controlled
* All other emissions (aircraft, GSE, and most GAV)
• Ownership and control are essential for mitigation planning
To gain recognition for emission reductions, the inventory needs to be structured
to show where/how reductions are achieved

17. Pollutants Considered in Airport
Inventories
• Identification of pollutants
– Pollutants
• Level 1: CO2 only
• Level 2: 6 Kyoto pollutants (CO2, CH4, N2O, SF6, HFC, PFC)
• Level 3: 6 Kyoto pollutants, Ozone, H2O, PM, and any others exerting GHG effects
– Level 2 is the “recommended” level
• Considerations
– Airport resources and inventory purpose/needs
– Availability and fidelity of data

18. Proposed EPA GHG reporting rule
• Proposed EPA Reporting Rules:
– 40 CFR 98 (NEW): Stationary Sources
• Airport stationary sources fall in general category of emissions >25,000 tons/yr.
• Our estimate is that some primary airports would be subject to this requirement in
2011.
• Airport growth (with no GHG mitigation) will result in more airports crossing EPA
reporting threshold
– 40 CFR 87 (AMENDED): Aircraft & Aircraft Engines
• Testing and reporting of GHG emission factors of aircraft sources
• Amended to add CH4 and CO2
• Newly reported indices should be used in the future for GHG
• Gap in reporting requirements regarding aircraft GHG emissions from flight and
ground operations
– Where does the reporting responsibility lie for various sources under new EPA rules?
– Who can claim credit for biojet use and renewables? And should LCA considerations be
factored in?

19. GHG Reduction or Growth mitigation?

20. Projected GHG & Other Emissions
• Recent IPCC report shows global
emissions of CO2 from air
transport grew BY 45% between
1992 and 2005.
• GHG emissions from aircraft
operations in the NAS currently
estimated at approximately
505,000 metric tons daily
• Preliminary study results show a
potential 8% increase in GHG
emissions by 2025 without the
accelerated introduction of
advanced vehicles
• Non-C02 climate forcing impacts
generally not accounted for – So,
impact estimates to be revised
upwards?

21. Non-CO2 Climate Forcing
• Radiative Forcing (RF) by non-CO2 emissions is computed using either the Global
Climate change Model (GCM) or the Chemical Transport Model (CTM)
• Non-CO2 emissions account for as much as half of aviation’s climate impacts
– Aviation’s contribution to radiative forcing is 4.9% of the global total and exceeds shipping
by 75% (ICAO)
NRA 2025
Baseline
Fuel
Burn
(Mt yr-1)
NOx
(Mt yr-
1)
Radiative Forcing (mW/m2)
CO2 O3* CH4* H2O Contrails
Sulfate
Aerosols
BC
Aerosols
Total RFI
73 0.73 8.86 6.83 -3.23 0.87 4.39 -1.52 1.09 17.29 2
O3 and CH4 RF are calculated based on NOx emission instead of fuel burnt

22. Summary & Conclusions
• Demand for air transportation to resume its upward climb, hence, increase in
GHG emissions absent game-changers
– What is a realistic objective for aviation? Reducing total GHG emissions or Reducing
the growth curve of GHG emissions?
• Aviation GHG impacts are not limited to flight operations. Airports have become
major economic engines and users of multiples services
– Airport ownership/control structure as well as scope of its activities matter in
determining approach to GHG inventory
• Climate Change is an evolving topic with more science and technology ahead –
e.g.,:
– Metrics and amalysis of non-CO2 climate forcing effects produced by aviation
– Need for agreement on LCA methodology and/or LCA-weighted factors for biofuels
(including blends)