NACAA Conference Call to Develop Comments on
EPA’s Proposed Aircraft Greenhouse Gas Endangerment Finding
and Advance Notice of Proposed Rulemaking
Wednesday, July 22, 2015
3:15 – 4:45 PM Eastern
Call-In Number: 866-365-4406, Access Code: 2682624#
Press *6 to mute your line and *7 to un-mute it
Summary of Aircraft GHG Endangerment Finding and ANPR
On June 10, 2015, EPA announced its proposal to determine that atmospheric greenhouse gas (GHG)
concentrations endanger the health and welfare of future generations within the meaning of §231(a) of the
Clean Air Act (CAA) and to find that GHG emissions from certain aircraft engines cause or contribute to air
pollution that endangers public health and welfare. This finding applies to the same six GHGs that were
identified in the agency’s 2009 endangerment finding under §202(a) of the CAA related to motor vehicles –
carbon dioxide (CO2), methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and carbon
hexafluoride. EPA issued this proposal in response to a citizen petition submitted to the agency in
December 2007 requesting that EPA make an endangerment finding and establish emission standards
under §231(a) for aircraft GHG emissions.
Covered aircraft engines include those used in U.S. subsonic jet aircraft with a maximum takeoff mass
(MTOM) of greater than 5,700 kilograms and in subsonic propeller-driven aircraft with an MTOM of greater
than 8,618 kilograms. Included among these types of engines are those used in smaller jet aircraft, like the
Cessna Citation CJ2, as well as in the largest jet aircraft, like the Airbus A380 and Boeing 747.
EPA’s proposed endangerment and contribution findings set the stage for potential harmonization of
international and U.S. CO2 aircraft emission standards. Over the past five years, the International Civil
Aviation Organization (ICAO) has been working on an international CO2 emission standard for aircraft; EPA
and the Federal Aviation Administration represent the U.S. in this effort. ICAO is expected to adopt an
international standard as early as next year.
Therefore, concurrent with its endangerment finding, EPA also issued an Advance Notice of Proposed
Rulemaking (ANPR) seeking public input on the process for establishment by ICAO of an international
aircraft CO2 emission standard and the potential use of CAA §231 to adopt and implement the ICAO
standard domestically. In particular, EPA seeks feedback on appropriate effective dates for a potential
international CO2 aircraft emission standard, appropriate stringency levels for such a standard and whether
international standards should apply to in-production aircraft as well as new aircraft types.
According to EPA, aircraft represent the single largest U.S. transportation source of GHG emissions not yet
subject to GHG standards, emitting 11 percent of GHG emissions from the U.S. transportation sector, 3
percent of total U.S. GHG emissions, 29 percent of GHG emissions from all aircraft worldwide and 0.5
percent total worldwide GHG emissions.
EPA published the proposed endangerment and contributions findings and ANPR in the Federal Register
on July 1, 2015 (80 Fed. Reg. 37,759). The public comment deadline is August 31, 2015. A public hearing
will be held on August 11, 2015 in Washington, DC.
Aircraft GHG Schedule
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June 10, 2015 – EPA announces aircraft GHG proposed endangerment finding and ANPR
July 1, 2015 – Proposal and ANPR published in the Federal Register
July 22, 2015 – NACAA membership call to develop comments
August 11, 2015 – Public hearing in Washington, DC
August 31, 2015 – Deadline for public comments
Aircraft GHG Resources
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Proposed Endangerment Finding and ANPR (80 Fed. Reg. 37,759, July 1, 2015):
http://www.gpo.gov/fdsys/pkg/FR-2015-07-01/pdf/2015-15192.pdf
EPA Aircraft GHG Website: http://www.epa.gov/otaq/aviation.htm
Potential Aircraft GHG Issues for Comment
Endangerment and Cause or Contribute Findings
Issues:
1) The EPA Administrator proposes to use the same definition of “air pollution” under CAA §231(a)(2)
as used under §202(a)(1) for the 2009 finding (the mix of six well-mixed GHGs: CO2, methane
nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride).
2) The EPA Administrator proposes to find, for the purposes of §231(a)(2), that elevated
concentrations of the six well-mixed GHGs constitutes air pollution that endangers both the public
health and the public welfare of current and future generations. The Administrator also proposes
that the body of scientific evidence in the record for the 2009 finding compellingly supports an
endangerment finding under §231(a)(2) and notes that information from new scientific
assessments further supports and justifies this proposed finding.
3) The EPA Administrator proposes that emissions of the well-mixed GHGs from classes of aircraft
engines used in covered aircraft (subsonic jet aircraft with a MTOM > 5,700 kilograms and
subsonic propeller-driven aircraft with a MTOM > 8,618 kilograms) cause or contribute to the air
pollution that endangers public health and welfare.
Recommended NACAA Comment: NACAA supports EPA’s proposed determination that atmospheric GHG
concentrations endanger the health and welfare of future generations within the meaning of CAA
§231(a)(2) and find that GHG emissions from certain aircraft engines cause or contribute to air pollution
that endangers public health and welfare. NACAA also supports EPA’s proposed definition of “air pollution”
under §231(a)(2).
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Advance Notice of Proposed Rulemaking
4) Issue: Should the U.S. continue to support adoption of an international CO2 emissions standard for
aircraft?
Recommended NACAA Comment: Yes
5) Issue: Need for EPA action
Recommended NACAA Comment: State and local air agencies are not authorized to regulate
aircraft emissions, therefore it is imperative that EPA propose and promulgate as rigorous and
comprehensive a rule as possible.
6) Issue: Applicability of aircraft CO2 standard:
a. To in-production aircraft, including aircraft with any engineered fuel efficiency
improvements (.e.g., different engines, redesigned wings, or engine performance
improvement packages)?
b. Only to completely new aircraft type designs?
c. To a redefined new aircraft type for CO2 purposes, to include in-production aircraft that
have a significant change in CO2 emissions?
d. In-production aircraft and new aircraft types?
Recommended NACAA Comment: International and domestic standards should apply to both inproduction aircraft and new aircraft types, with “in-production” aircraft defined as any covered
aircraft that is produced after the compliance deadline.
7) Issue: Effective date of a potential international CO2 standard
Recommended NACAA Comment: The effective dates should be not later than 2023 (earlier?) for
in-production; 2020 for new type.
8) Issue: Reporting requirements for in-production aircraft
Recommended NACAA Comment: All in-production aircraft and their associated emissions should
be reported.
9) Issue: Stringency of a potential international CO2 standard (in-production and new type standards)
Recommended NACAA Comment: In the ANPR, EPA appears to presume standards that are
technology following (i.e., based on technology that is in existence in 2016). EPA should propose
and promulgate standards that are technology forcing.
10) Issue: EPA adoption of a more stringent aircraft emission standard than ICAO
Recommended NACAA Comment: EPA must be prepared to adopt a more stringent aircraft
emission standard than ICAO if the international standard falls short (including, among other
things, if ICAO does not include in-production aircraft as described above and if the standards are
not sufficiently stringent).
11) Issue: Engines associated with aircraft
Recommended NACAA Comment: Engines associated with, but not part of, an aircraft should also
be addressed in a proposed EPA rule. Key among these are auxiliary power units (APUs). It does
not appear that ICAO will address APUs, therefore EPA should lead on this issue and propose to
reduce emissions from APUs.
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12) Issue: Standards for in-use aircraft
Recommended NACAA Comment: EPA should pursue opportunities for establishing standards for
in-use aircraft, which, for example, can be retrofitted with winglets, which can reduce drag and
save fuel.
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