Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute to Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare

Federal RegisterAug 15, 2016

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 87 and 1068

[EPA-HQ-OAR-2014-0828; FRL-9950-15-OAR]

RIN 2060-AS31

Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute to Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

In this action, the Administrator finds that elevated concentrations of greenhouse gases in the atmosphere endanger the public health and welfare of current and future generations within the meaning of section 231(a)(2)(A) of the Clean Air Act (CAA, or Act). She makes this finding specifically with respect to the same six well-mixed greenhouse gases—carbon dioxide (CO

), methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride—that together were defined as the air pollution in the 2009 Endangerment Finding under section 202(a) of the CAA and that together constitute the primary cause of the climate change problem. The Administrator also finds that emissions of those six well-mixed greenhouse gases from certain classes of engines used in certain aircraft are contributing to the air pollution—the aggregate group of the same six greenhouse gases—that endangers public health and welfare under CAA section 231(a)(2)(A).

DATES:

These findings are effective on September 14, 2016.

ADDRESSES:

The EPA has established a docket for this rulemaking under Docket ID No. EPA-HQ-OAR-2014-0828. All documents in the docket are listed in the

www.regulations.gov

Web site. Although listed in the index, some information is not publicly available,

e.g.,

confidential business information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy in the EPA's docket. Publicly available docket materials are available either electronically in

www.regulations.gov

or in hard copy at the Air and Radiation Docket and Information Center, EPA/DC, EPA WJC West, Room 3334, 1301 Constitution Ave. NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the Air Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT:

Lesley Jantarasami, Office of Atmospheric Programs, Climate Change Division, Environmental Protection Agency, 1200 Pennsylvania Ave. NW., Mail Code 6207-A, Washington, DC 20460; Telephone number: (202) 343-9990; Email address:

ghgendangerment@epa.gov

. For additional information regarding these final findings, please go to the Web site

http://www3.epa.gov/otaq/climate/regs-aviation.htm.

SUPPLEMENTARY INFORMATION:

Judicial Review

Under CAA section 307(b)(1), judicial review of this final action is available only by filing a petition for review in the U.S. Court of Appeals for the District of Columbia Circuit by October 14, 2016. This final action is a nationally applicable action because it triggers the EPA's statutory duty to promulgate aircraft engine emission standards under CAA section 231, which are nationally applicable regulations and for which judicial review will be available only in the U.S. Court of Appeals for the District of Columbia Circuit. In the alternative, even if this action were considered to be only locally or regionally applicable, the Administrator determines that it has nationwide scope and effect within the meaning of CAA section 307(b)(1) both because of the obligation to establish standards under CAA section 231 that it triggers and because it concerns risks from GHG pollution and contributions to such pollution that occur across the nation. Under CAA section 307(d)(7)(B), only an objection to this final action that was raised with reasonable specificity during the period for public comment can be raised during judicial review. This section also provides a mechanism for us to convene a proceeding for reconsideration, “[i]f the person raising an objection can demonstrate to [EPA] that it was impracticable to raise such objection within [the period for public comment] or if the grounds for such objection arose after the period for public comment (but within the time specified for judicial review) and if such objection is of central relevance to the outcome of this rule.” Any person seeking to make such a demonstration to us should submit a Petition for Reconsideration to the Office of the Administrator, Environmental Protection Agency, Room 3000, William Jefferson Clinton Building, 1200 Pennsylvania Ave. NW., Washington, DC 20460, with a copy to the person listed in the preceding

FOR FURTHER INFORMATION CONTACT

section, and the Associate General Counsel for the Air and Radiation Law Office, Office of General Counsel (Mail Code 2344-A) Environmental Protection Agency, 1200 Pennsylvania Ave. NW., Washington, DC 20460.

Table of Contents

I. General Information

A. Does this action apply to me?

II. Introduction: Overview and Context for This Final Action

A. Summary

B. Background Information Helpful To Understanding This Final Action

C. The EPA's Responsibilities Under the Clean Air Act

D. U.S. Aircraft Regulations and the International Community

III. Legal Framework for This Action

A. Section 231(a)(2)(A)—Endangerment and Cause or Contribute

B. Air Pollutant, Public Health and Welfare

IV. The Administrator's Finding Under CAA Section 231 That Greenhouse Gases Endanger Public Health and Welfare

A. The Science Upon Which the Agency Relied

B. The Air Pollution Consists of Six Key Well-Mixed Greenhouse Gases

C. The Air Pollution Is Reasonably Anticipated To Endanger Both Public Health and Welfare

D. Summary of the Administrator's Endangerment Finding Under CAA Section 231

V. The Administrator's Cause or Contribute Finding for Greenhouse Gases Emitted by Certain Classes of Engines Used by Covered Aircraft Under CAA Section 231

A. The Air Pollutant

B. The Administrator's Finding Under CAA Section 231(a)(2)(A) That Greenhouse Gas Emissions From Certain Classes of Aircraft Engines Used in Certain Aircraft Cause or Contribute to Air Pollution That May Be Reasonably Anticipated To Endanger Public Health and Welfare

C. Response to Key Comments on the Administrator's Cause or Contribute Finding

VI. Statutory Authority and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review

B. Paperwork Reduction Act (PRA)

C. Regulatory Flexibility Act (RFA)

D. Unfunded Mandates Reform Act (UMRA)

E. Executive Order 13132: Federalism

F. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments

G. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks

H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution or Use

I. National Technology Transfer and Advancement Act (NTTAA)

J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations

K. Congressional Review Act (CRA)

L. Determination Under Section 307(d)

VII. Statutory Provisions and Legal Authority

I. General Information

A. Does this action apply to me?

These final findings trigger new duties that apply to the EPA but do not themselves apply new requirements to other entities outside the federal government. Specifically, in issuing these final findings that emissions of the six well-mixed GHGs from certain classes of engines used in certain aircraft cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare, the EPA becomes subject to a duty under CAA section 231 to propose and promulgate aircraft engine emission standards applicable to emissions of that air pollutant from those classes of engines. We are anticipating indicating an expected timeline for proposed GHG emission standards for the classes of aircraft engines included in the contribution finding in EPA's Unified Agenda of Federal Regulatory and Deregulatory Actions. Only those future standards will apply to and have an effect on other entities outside the federal government. Entities potentially interested in this final action include those that manufacture and sell aircraft engines and aircraft in the United States. Categories that may be regulated in a future regulatory action

include:

Manufacturers of new aircraft engines refers to manufacturers of new type engines and in-production engines, and manufacturers of new aircraft refers to manufacturers of new type aircraft and in-production aircraft.

Category

NAICS

Code

SIC

Code

Examples of Potentially Affected Entities

Industry

3364412

3724

Manufacturers of new aircraft engines.

Industry

336411

3721

Manufacturers of new aircraft.

North American Industry Classification System (NAICS).

Standard Industrial Classification (SIC) code.

This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be interested in this final action. This table lists the types of entities that the EPA is now aware could potentially have an interest in this final action. By issuing these final findings under CAA section 231(a)(2)(A) regarding emissions of greenhouse gases from aircraft engines, the EPA is now required to undertake a separate notice and comment rulemaking to propose and issue emission standards applicable to greenhouse gas emissions from the classes of aircraft engines subject to the findings, and the Federal Aviation Administration (FAA) is to prescribe regulations to ensure compliance with EPA's future emissions standards pursuant to CAA section 232. Other types of entities not listed in the table could also be interested and potentially affected by subsequent actions at some future time. If you have any questions regarding the scope of this final action, consult the person listed in the preceding

FOR FURTHER INFORMATION CONTACT

section.

II. Introduction: Overview and Context for This Final Action

A. Summary

Pursuant to CAA section 231(a)(2)(A), the Administrator finds that emissions of the six well-mixed

greenhouse gases (GHGs) from certain classes of aircraft engines used in certain types of aircraft (referred to interchangeably as “covered aircraft” or “US covered aircraft” throughout this document) contribute to air pollution that may reasonably be anticipated to endanger the public health and welfare of current and future generations. This final action follows the Administrator's proposed findings,

and responds to public comments submitted to the EPA following that proposal. It is based on careful consideration of the scientific evidence, as well as a thorough review of the public comments. In light of the large number of comments received and overlap between many comments, EPA has not responded to each comment individually. Instead, EPA has summarized and provided responses to each significant argument, assertion and question contained within the totality of these comments. Covered aircraft are those aircraft to which the International Civil Aviation Organization (ICAO) has agreed the recently recommended international CO

standard will apply

: Subsonic jet aircraft with a maximum takeoff mass (MTOM) greater than 5,700 kilograms and subsonic propeller-driven (

e.g.,

turboprop) aircraft with a MTOM greater than 8,618 kilograms. Examples of covered aircraft include smaller jet aircraft such as the Cessna Citation CJ3+ and the Embraer E170, up to and including the largest commercial jet aircraft—the Airbus A380 and the Boeing 747. Other examples of covered aircraft include larger turboprop aircraft, such as the ATR 72 and the Bombardier Q400.

The term “well-mixed GHGs”—used both in the definition of “air pollution” in the endangerment finding and in the definition of “air pollutant” in the cause or contribute finding—is based on the fact that these gases are sufficiently long lived in the atmosphere such that, once emitted, concentrations of each gas become well mixed throughout the entire global atmosphere. These shared attributes are one of five primary reasons that the EPA considers the six gases as an aggregate group rather than as individual gases. See section IV.B for more information on the definition of “air pollution” and section V.A for more information on the definition of the “air pollutant.”

U.S. EPA, 2015:

Proposed Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute To Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare and Advance Notice of Proposed Rulemaking; Proposed Rule,

Federal Register

(FR) 37758 (July 1, 2015).

ICAO, 2013:

CAEP/9 Agreed Certification Requirement for the Aeroplane CO2 Emissions Standards,

Circular (Cir) 337, 40 pp, AN/192, Available at:

http://www.icao.int/publications/catalogue/cat_2016_en.pdf

(last accessed May 9, 2016). The ICAO Circular 337 is found on page 87 of the catalog and is copyright protected; Order No. CIR337.

In this final action, the EPA is informed by and places considerable weight on the extensive scientific and technical evidence in the record supporting the 2009 Endangerment and Cause or Contribute Findings under CAA section 202(a) (hereafter, collectively referred to as the 2009 Endangerment Finding).

This includes the major, peer-reviewed scientific assessments that were used to address the question of whether elevated concentrations of GHGs in the

atmosphere endanger public health and welfare under CAA section 202(a), as well as the analytical framework and conclusions upon which the EPA relied in making that finding. The Administrator's view is that the body of scientific evidence amassed in the record for the 2009 Endangerment Finding also compellingly supports an endangerment finding under CAA section 231(a)(2)(A). Furthermore, this finding under section 231(a)(2)(A) reflects the EPA's careful consideration not only of the scientific and technical record for the 2009 Endangerment Finding, but also of science assessments released since 2009, which, as illustrated below, strengthen and further support the judgment that GHGs in the atmosphere may reasonably be anticipated to endanger the public health and welfare of current and future generations. No information or assessments published since late 2009 suggest that it would be reasonable for the EPA to now reach a different or contrary conclusion for purposes of CAA section 231(a)(2)(A) than the Agency reached for purposes of section 202(a).

U.S. EPA, 2009:

Endangerment and Cause or Contribute Findings for Greenhouse Gases Under Section 202(a) of the Clean Air Act; Final Rule,

74 FR 66496 (December 15, 2009).

The Administrator defines the “air pollution” referred to in section 231(a)(2)(A) of the CAA to be the combined mix of CO

, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride (henceforth the six “well-mixed GHGs”). This is the same definition that was used for the finding for purposes of section 202(a). It is the Administrator's judgment that the total body of scientific evidence compellingly supports a positive endangerment finding that elevated concentrations of the six well-mixed GHGs constitute air pollution that endangers both the public health and welfare of current and future generations within the meaning of CAA section 231(a)(2)(A). The Administrator is not at this time making a finding regarding whether other substances emitted from aircraft engines cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare.

Under CAA section 231(a)(2)(A), the Administrator must also determine whether emissions of any air pollutant from a class or classes of aircraft engines cause or contribute to the air pollution that may reasonably be anticipated to endanger public health or welfare. Following the rationale outlined in the 2009 Endangerment Finding, the Administrator in this action is using the same definition of the air pollutant as was used for purposes of section 202(a) for purposes of making the cause or contribute determination under section 231(a)(2)(A)—that is, the aggregate group of the same six well-mixed GHGs. With respect to this pollutant, based on the data summarized in section V.B, the Administrator finds that emissions of the six well-mixed GHGs from aircraft engines used in covered aircraft contribute to the air pollution that endangers public health and welfare under section 231(a)(2)(A). The Administrator is not at this time making a cause or contribute finding regarding GHG emissions, or emissions of other substances, from engines used in non-covered aircraft.

The Administrator's final findings come in response to a citizen petition submitted by Friends of the Earth, Oceana, the Center for Biological Diversity, and Earthjustice (Petitioners) requesting that the EPA issue an endangerment finding and standards under CAA section 231(a)(2)(A) for the GHG emissions from aircraft. Further, the EPA anticipates that the 39th ICAO Assembly will approve a final CO

emissions standard in October 2016, and that subsequently, ICAO will formally adopt the final CO

emissions standard in March 2017. These final endangerment and cause or contribute findings for aircraft engine GHG emissions are also part of preparing for a subsequent domestic rulemaking process under CAA section 231. If an international standard is approved and finalized by ICAO, member states that wish to use aircraft in international transportation will then be required under the Chicago Convention

to adopt standards that are of at least equivalent stringency to those set by ICAO. Section II.D provides additional discussion of the international aircraft standard-setting process. This document does not take action or respond to comments on the 2015 U.S. EPA Aircraft Greenhouse Gas Emissions Advance Notice of Proposed Rulemaking (henceforth the “2015 ANPR”),

which discussed such standards. Technical issues and comments for the 2015 ANPR would be addressed in a future notice of proposed rulemaking related to such standards.

ICAO, 2006:

Convention on International Civil Aviation, Ninth Edition,

Document 7300/9, 114 pp. Available at:

http://www.icao.int/publications/Documents/7300_9ed.pdf

(last accessed May 9, 2016).

80 FR 37758 (July 1, 2015).

B. Background Information Helpful to Understanding This Final Action

1. Greenhouse Gases and Their Effects

GHGs in the atmosphere have the effect of trapping some of the Earth's heat that would otherwise escape to space. GHGs are both naturally occurring and anthropogenic. The primary GHGs directly emitted by human activities include CO

, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. Of these six gases, two (CO

and nitrous oxide) are emitted by aircraft engines.

These six gases, once emitted, remain in the atmosphere for decades to centuries. Thus, they become well mixed globally in the atmosphere, and their concentrations accumulate when emissions exceed the rate at which natural processes remove them from the atmosphere. Observations of the Earth's globally averaged combined land and ocean surface temperature over the period 1880 to 2012 show a warming of 0.85 degrees Celsius or 1.53 degrees Fahrenheit.

The Intergovernmental Panel on Climate Change's (IPCC) 2013-2014 Fifth Assessment Report concluded that heating effect caused by the human-induced buildup of these and other GHGs in the atmosphere, plus other human activities (

e.g.,

land use change and aerosol emissions), is extremely likely (>95 percent likelihood) to be the cause of most of the observed global warming since the mid-20th century.

Further information about climate change and its impact on health, society, and the environment is included in the record for the 2009 Endangerment Finding. The relevant scientific information from that record has also been included in the docket for this determination under CAA section 231(a)(2)(A) (EPA-HQ-OAR-2014-0828). Section IV of this preamble discusses this information, as well as information from the most recent scientific assessments, in the context of the Administrator's endangerment finding under CAA section 231.

IPCC, 2013:

Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis.

Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, 29 pp.

Ibid.

The U.S. transportation sector constitutes a meaningful part of total U.S. and global anthropogenic GHG emissions. In 2014, aircraft remained the single largest GHG-emitting transportation source not yet subject to any GHG standards. Aircraft clearly contribute to U.S. transportation emissions, accounting for 12 percent of all U.S. transportation GHG emissions and representing more than 3 percent of total U.S. GHG emissions in 2014.

Globally, U.S. aircraft GHG emissions represent 29 percent of all global aircraft GHG emissions and 0.5 percent of total global GHG emissions. Section V of this preamble provides detailed information on aircraft GHG emissions in the context of the Administrator's cause or contribute finding under CAA section 231(a)(2)(A).

U.S. EPA, 2016:

Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014,

1,052 pp., U.S. EPA Office of Air and Radiation, EPA 430-R-

16-002, April 2016. Available at:

www3.epa.gov/climatechange/ghgemissions/usinventoryreport.html

(last accessed June 14, 2016).

2. Statutory Basis for This Final Action

Section 231(a)(2)(A) of the CAA states that “The Administrator shall, from time to time, issue proposed emission standards applicable to the emission of any air pollutant from any class or classes of aircraft engines which in [her] judgment causes, or contributes to, air pollution which may reasonably be anticipated to endanger public health or welfare.”

Before the Administrator may propose and issue final standards addressing emissions of an air pollutant under section 231, the Administrator must satisfy a two-step test. First, the Administrator must decide whether, in her judgment, the air pollution under consideration may reasonably be anticipated to endanger public health or welfare. Second, the Administrator must decide whether, in her judgment, emissions of an air pollutant from certain classes of aircraft engines cause or contribute to this air pollution.

If the Administrator answers both questions in the affirmative, she must propose and issue final standards under section 231.

See Massachusetts

EPA,

549 U.S. 497, 533 (2007) (interpreting analogous provision in CAA section 202). Section III of this document summarizes the legal framework for this final action under CAA section 231. Typically, past endangerment and cause or contribute findings have been proposed and promulgated concurrently with proposed and promulgated standards under various sections of the CAA, including section 231. In those actions, public comment was taken on the proposed findings as part of the notice and comment process for the proposed emission standards.

See, e.g.,

Rulemaking for non-road compression-ignition engines under section 213(a)(4) of the CAA, Proposed Rule at 58 FR 28809, 28813-14 (May 17, 1993), Final Rule at 59 FR 31306, 31318 (June 17, 1994); Rulemaking for highway heavy-duty diesel engines and diesel sulfur fuel under sections 202(a) and 211(c) of the CAA, Proposed Rule at 65 FR 35430 (June 2, 2000), and Final Rule at 66 FR 5002 (January 18, 2001). However, there is no requirement that the Administrator propose or finalize the endangerment and cause or contribute findings concurrently with the related standards. See 74 FR 66502 (December 15, 2009). As explained in the 2009 Endangerment Finding, nothing in section 202(a) requires the EPA to propose or issue endangerment and cause or contribute findings in the same rulemaking, and Congress left the EPA discretion to choose an approach that satisfied the requirements of section 202(a). See id. The same analysis applies to section 231, which is analogous to section 202(a). The EPA is choosing to finalize these findings at this time for a number of reasons, including its previous commitment to issue such findings in response to a 2007 citizens' petition.

To clarify the distinction between air pollution and air pollutant, in the context of GHGs, the air pollution is the atmospheric concentrations and can be thought of as the total, cumulative stock of GHGs in the atmosphere. The air pollutant, on the other hand, is the emissions of GHGs and can be thought of as the flow that changes the size of the total stock.

Center for Biological Diversity, Center for Food Safety, Friends of the Earth, International Center for Technology Assessment, and Oceana, 2007: Petition for Rulemaking Under the Clean Air Act to Reduce the Emissions of Air Pollutants from Aircraft the Contribute to Global Climate Change, December 31, 2007. Available at

http://www3.epa.gov/otaq/aviation.htm

(last accessed April 8, 2016). EPA, 2012: Response to the Petition for Rulemaking Under the Clean Air Act to Reduce the Emission of Air Pollutants from Aircraft that Contribute to Global Climate Change, June 14, 2012. Available at

http://www3.epa.gov/otaq/aviation.htm

(last accessed April 8, 2016).

The Administrator has applied the rulemaking provisions of CAA section 307(d) to this action, pursuant to CAA section 307(d)(1)(V), which provides that the provisions of 307(d) apply to “such other actions as the Administrator may determine.”

CAA section 307(d) provides specific procedural requirements for the EPA to follow in taking certain rulemaking actions under the CAA, that apply in lieu of the otherwise applicable provisions of the Administrative Procedure Act, 5 U.S.C. 553-557, and 706.

See,

CAA section 307(d)(1). Any standard-setting rulemaking under section 231 will also be subject to the notice and comment rulemaking procedures under 307(d), as provided in CAA section 307(d)(1)(F) (applying the provisions of 307(d) to the promulgation or revision of any aircraft emission standard under section 231). Thus, these findings were subject to the same rulemaking procedures and requirements, as applicable, as would have applied if they had been part of a standard-setting rulemaking.

As the Administrator is applying the provisions of section 307(d) to this rulemaking under section 307(d)(1)(V), we need not determine whether those provisions would apply to this action under section 307(d)(1)(F).

C. The EPA's Responsibilities Under the Clean Air Act

The CAA provides broad authority to combat air pollution to protect public health and welfare and the environment. Cars, trucks, construction equipment, airplanes, and ships, as well as a broad range of electricity generation, industrial, commercial and other facilities, are subject to various CAA programs. Many of these programs are targeted at ensuring protection of public health and welfare with a margin of safety, others are directed at encouraging improved industrial emissions performance and use of lesser polluting technologies and processes, and some address the prevention of adverse environmental effects. Implementation of the Act over the past four decades has resulted in significant reductions in air pollution that have benefited human health and the environment. The EPA's duties regarding aircraft air pollution emissions under CAA section 231 reflect a combination of the CAA's goals to protect public health and welfare and encourage improved emissions performance. This is shown by section 231(a)(2)(A)'s directive that EPA first identify whether emissions of aircraft engine air pollutants cause or contribute to air pollution that may reasonably be anticipated to endanger public health or welfare (which is broadly defined in section 302(h) of the CAA).

This is also shown by section 231(b)'s subsequent requirement that EPA's standards, which may require improved emissions performance over the

status quo,

provide sufficient time for the development and application of requisite technology to meet emission standards, after consideration of costs.

Previously the EPA has made the prerequisite endangerment and cause or contribute findings under CAA section 231(A) that formed the basis to begin addressing the issue of various aircraft pollutants including NO

aircraft pollution. U.S. EPA, “Control of Air Pollution from Aircraft and Aircraft Engines, Emission Standards and Test Procedures for Aircraft.” Final Rule, 38 FR 19088 (July 17, 1973). See also section IV.B.7.d of this preamble for a discussion of previous NO

section 231(A) findings.

1. The EPA's Regulation of Greenhouse Gases

Massachusetts

EPA,

549 U.S. 497 (2007), the Supreme Court found that GHGs are air pollutants that can be regulated under the CAA. The Court held that the Administrator must determine whether emissions of GHGs from new motor vehicles cause or contribute to air pollution which may

reasonably be anticipated to endanger public health and/or welfare, or whether the science is too uncertain to make a reasoned decision. In making these decisions, the Administrator was bound by the provisions of section 202(a) of the CAA. The Supreme Court decision resulted from a petition for rulemaking under section 202(a) filed by more than a dozen environmental, renewable energy, and other organizations.

Following the Supreme Court decision, the EPA proposed (74 FR 18886, April 24, 2009) and then finalized (74 FR 66496, December 15, 2009) the 2009 Endangerment Finding, which can be summarized as follows:

• Endangerment Finding: The Administrator found that the then-current and projected concentrations of the combined mix in the atmosphere of the six well-mixed GHGs—CO

, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride—endanger the public health and welfare of current and future generations.

• Cause or Contribute Finding: The Administrator found that the combined emissions of the six well-mixed GHGs from new motor vehicles and new motor vehicle engines contribute to the GHG pollution which threatens public health and welfare.

The Administrator made both of these findings with respect to the six well-mixed GHGs, recognizing that CAA section 202(a) sources emit only four of the six substances. The findings did not themselves impose any requirements on industry or other entities. However, these findings compelled the EPA to promulgate GHG emission standards for new motor vehicles under section 202(a). Subsequently, in May 2010 the EPA, in collaboration with the National Highway Traffic Safety Administration (NHTSA), finalized Phase 1 GHG emission standards for light-duty vehicles (2012-2016 model years).

This was followed in August 2011 by adoption of the first-ever GHG emission standards for heavy-duty engines and vehicles (2014-2018 model years).

On August 29, 2012, the EPA finalized the second phase of the GHG emission standards for light-duty vehicles (2017-2025 model years), further reducing GHG emissions from light-duty vehicles.

In 2014, the President directed the EPA and the Department of Transportation to set standards in 2016 that further increase fuel efficiency and reduce GHG emissions from medium- and heavy-duty vehicles.

U.S. EPA, 2010:

Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards; Final Rule,

75 FR 25324 (May 7, 2010).

U.S. EPA, 2011:

Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles; Final Rule,

76 FR 57106 (September 15, 2011).

U.S. EPA, 2012:

2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions and Corporate Average Fuel Economy Standards; Final Rule,

77 FR 62623 (October 15, 2012).

Executive Office of the President, 2014:

Remarks by the President on Fuel Efficiency Standards of Medium and Heavy-Duty Vehicles,

Office of the Press Secretary, February 18. Available at:

https://www.whitehouse.gov/the-press-office/2014/02/18/remarks-president-fuel-efficiency-standards-medium-and-heavy-duty-vehicl

(last accessed April 27, 2016).

The GHG rules for cars and trucks have been supported by a broad range of stakeholders, including states, major automobile and truck manufacturers, and environmental and labor organizations. Together these new standards for cars and trucks are resulting in significant reductions in GHG emissions, and over the lifetime of these vehicles GHG emissions will have been reduced more than 6.25 billion metric tons.

19 20

U.S. EPA, 2012:

EPA and NHTSA Set Standards to Reduce Greenhouse Gases and Improve Fuel Economy for Model Years 2017-2025 Cars and Light Trucks.

Document No. EPA-420-F-12-051, 10 pp. Available at

http://www.epa.gov/otaq/climate/documents/420f12051.pdf

(last accessed April 27, 2016). See also Table 7.4-2 in U.S. EPA, 2012:

Regulatory Impact Analysis: Final Rulemaking for 2017-2025 Light-Duty Vehicle Greenhouse Gas Emissions Standards and Corporation Average Fuel Economy Standards,

EPA-420-R-12-016, 555 pp. Available at:

https://www3.epa.gov/otaq/climate/documents/420r12016.pdf

(last accessed April 27, 2016).

U.S. EPA, 2011:

Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium-and Heavy-Duty Engines and Vehicles; Final Rule,

76 FR 57106 (September 15, 2011).

On June 25, 2013, President Obama announced a Climate Action Plan that set forth a series of executive actions to further reduce GHGs, prepare the U.S. for the impacts of climate change, and lead international efforts to address global climate change.

As part of the Climate Action Plan, the President issued a Presidential Memorandum directing the EPA to work expeditiously to complete carbon pollution standards for the power sector.

In August 2015, after notice and comment rulemaking, the EPA finalized two carbon pollution rulemakings: One for new, modified, and reconstructed electric utility generating units

and another for existing power plants.

Executive Office of the President, 2013:

The President's Climate Action Plan,

June 25, 21 pp. Available at:

http://www.whitehouse.gov/sites/default/files/image/president27sclimateactionplan.pdf

(last accessed April 8, 2016).

Executive Office of the President, 2013:

Presidential Memorandum—Power Sector Carbon Pollution Standards,

Office of the Press Secretary, June 25. Available at:

http://www.whitehouse.gov/the-press-office/2013/06/25/presidential-memorandum-power-sector-carbon-pollution-standards

(last accessed April 8, 2016).

U.S. EPA, 2015:

Standards of Performance for Greenhouse Gas Emissions From New, Modified, and Reconstructed Stationary Sources: Electric Utility Generating Units; Final Rule,

80 FR 64510 (October 23, 2015).

U.S. EPA, 2014:

Carbon Pollution Emission Guidelines for Existing Stationary Sources: Electric Utility Generating Units; Final Rule,

80 FR 64661 (October 23, 2015). On February 9, 2016 the Supreme Court stayed this rule pending judicial review. The Court's stay order does not articulate a basis for the stay and does not address the merits of the rule.

In the Climate Action Plan, the President also indicated that the United States was working internationally to make progress in a variety of areas and specifically noted the progress being made by ICAO to develop global CO

emission standards for aircraft.

The final endangerment and cause or contribute findings for aircraft GHG emissions under section 231(a)(2)(A) of the CAA are a preliminary but necessary first step to begin to address GHG emissions from the aviation sector, the highest-emitting category of transportation sources that the EPA has not yet addressed. As presented in more detail in Section V of this document, total U.S. aircraft GHG emissions in 2014 represented 12 percent of GHG emissions from the U.S. transportation sector,

and in 2010, the latest year with complete global emissions data, U.S. aircraft GHG emissions represented 29 percent of global aircraft GHG emissions.

27 28

U.S. aircraft GHG emissions are projected to increase by 43 percent over the next two decades.

See section V of this preamble for more information about the data sources that comprise the aircraft GHG emissions inventory.

Executive Office of the President, 2013:

The President's Climate Action Plan, June 25, 21 pp.

Available at

http://www.whitehouse.gov/sites/default/files/image/president27sclimateactionplan.pdf

(last accessed April 8, 2016).

U.S. EPA, 2016:

Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014,

1,052 pp., U.S. EPA Office of Air and Radiation, EPA 430-R-16-002, April 2016. Available at:

www3.epa.gov/climatechange/ghgemissions/usinventoryreport.html

(last accessed June 14, 2016).

Ibid.

IPCC, 2014:

Climate Change 2014: Mitigation of Climate Change.

Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Edenhofer, O., R. Pichs-Madruga, Y. Sokona, E. Farahani, S. Kadner, K. Seyboth, A. Adler, I. Baum, S. Brunner, P. Eickemeier, B. Kriemann, J. Savolainen, S. Schlömer, C. von Stechow, T. Zwickel and J.C. Minx (eds.)]. Cambridge University Press, pp. 599-670.

As discussed in section V.B.4.c, fuel burn growth rates for air carriers and general aviation aircraft operating on jet fuel are projected to grow by 43 percent from 2010 to 2036, and this provides a scaling factor for growth in GHG emissions which would increase at a similar rate as the fuel burn by 2030, 2036, and 2040. FAA, 2016:

FAA Aerospace Forecast Fiscal Years 2016-2036,

94 pp. Available at

https://www.faa.gov/data_research/aviation/aerospace_forecasts/media/FY2016-36_FAA_

Aerospace_Forecast.pdf

(last accessed April 8, 2016).

2. Background on the Aircraft Petition, the 2008 Advance Notice of Proposed Rulemaking, and the D.C. District Court Decision

Section 231(a)(2)(A) of the CAA directs the Administrator of the EPA to, from time to time, propose aircraft engine emissions standards applicable to the emission of any air pollutant from any classes of aircraft engines which in her judgment causes or contributes to air pollution which may reasonably be anticipated to endanger public health or welfare.

On December 5, 2007, Friends of the Earth, Oceana, the Center for Biological Diversity, Earthjustice, and others (Petitioners) sent a letter to the EPA petitioning the Agency to undertake rulemaking regarding GHG emissions from aircraft.

Specifically, Petitioners requested that the EPA make a finding that GHG emissions from aircraft engines “may reasonably be anticipated to endanger public health and welfare” and that the EPA promulgate standards for GHG emissions from aircraft.

Center for Biological Diversity, Center for Food Safety, Friends of the Earth, International Center for Technology Assessment, and Oceana, 2007:

Petition for Rulemaking Under the Clean Air Act to Reduce the Emissions of Air Pollutants from Aircraft the Contribute to Global Climate Change,

December 5, 26 pp. Available at

http://www.epa.gov/otaq/aviation.htm

(last accessed April 8, 2016) and Docket EPA-HQ-OAR-2014-0828.

Following the Supreme Court's decision in

Massachusetts

EPA

in 2007, the EPA issued an advance notice of proposed rulemaking (ANPR) in 2008 presenting information relevant to potentially regulating GHGs under the Act and soliciting public comment on how to respond to the Court's ruling and the potential ramifications of the Agency's decision to regulate GHGs under the CAA. This ANPR described and solicited comment on numerous petitions the Agency had received to regulate GHG emissions from both stationary and mobile sources, including aircraft. 73 FR 44354, 44468-73 (July 30, 2008). With regard to aircraft, the Agency sought comment on the impact of aircraft operations on GHG emissions and the potential for reductions in GHG emissions from these operations.

On July 31, 2008, Earthjustice, on behalf of Petitioners, notified the EPA of its intent to file suit under CAA section 304(a) against the EPA for the Agency's alleged unreasonable delay in responding to its aircraft petition and in making an endangerment finding under section 231. On June 11, 2010, Petitioners filed a complaint against the EPA in the U.S. District Court for the District of Columbia claiming that, among other things, the EPA had unreasonably delayed because it had failed to answer the 2007 Petition and to determine whether GHG emissions from aircraft cause or contribute to air pollution which may reasonably be anticipated to endanger public health and/or welfare.

The District Court found that while CAA section 231 generally confers broad discretion to the EPA in determining what standards to promulgate, section 231(a)(2)(A) imposed a nondiscretionary duty on the EPA to make a finding with respect to endangerment from aircraft GHG emissions.

Center for Biological Diversity, et al.

EPA,

794 F. Supp. 2d 151 (D.D.C. 2011). This ruling was issued in response to the EPA's motion to dismiss the case on jurisdictional grounds and did not address the merits of the Plaintiffs' claims regarding the Agency's alleged unreasonable delay. Therefore, it did not include an order for the EPA to make such a finding by a certain date. In a subsequent ruling on the merits, the Court found that the Plaintiffs had not shown that the EPA had unreasonably delayed in making an endangerment determination regarding GHG emissions from aircraft.

Center for Biological Diversity, et al.

EPA,

No. 1:10-985 (D.D.C. March, 20, 2012). Thus, the Court did not find the EPA to be liable based on the Plaintiffs' claims and did not place the Agency under a remedial order to make an endangerment finding or to issue standards. The Plaintiffs did not appeal this ruling to the U.S. Court of Appeals for the District of Columbia Circuit (also called the “D.C. Circuit” in this document).

The EPA issued a Response to the Aircraft Petition

on June 27, 2012, stating our intention to move forward with a proposed endangerment finding for aircraft GHG emissions under section 231, while explaining that it would take the Agency significant time to complete this action. The EPA explained that the Agency would not begin this effort until after the U.S. Court of Appeals completed its then-pending review of the previous section 202 Endangerment Finding, since the then-awaited ruling might provide important guidance for the EPA in conducting future GHG endangerment findings. The EPA further explained that after receiving the Court of Appeal's ruling, it would take at least 22 months from that point for the Agency to conduct an additional finding regarding aircraft GHG emissions.

U.S. EPA, 2012:

Memorandum in Response to Petition Regarding Greenhouse Gas Emissions from Aircraft,

June 14, 11 pp. Available at

http://www.epa.gov/otaq/aviation.htm

(last accessed April 8, 2016) and Docket EPA-HQ-OAR-2014-0828.

Meanwhile, the Court of Appeals upheld the EPA's section 202 findings in a decision of a three-judge panel on June 26, 2012, and denied petitions for rehearing of that decision on December 20, 2012.

Coalition for Responsible Regulation, Inc.,

EPA,

684 F.3d 102 (D.C. Cir. 2012), reh'g denied 2012 U.S. App. LEXIS 26315, 25997 (D.C. Cir 2012).

Given these rulings, we are proceeding with these findings regarding aircraft engine GHG emissions as a further step toward responding to the 2007 Petition for Rulemaking.

Petitions for

certiorari

were filed in the Supreme Court, and the Supreme Court granted six of those petitions but “agreed to decide only one question: ‘Whether EPA permissibly determined that its regulation of greenhouse gas emissions from new motor vehicles triggered permitting requirements under the Clean Air Act for stationary sources that emit greenhouse gases.’ ”

Utility Air Reg. Group

EPA,

134 S. Ct. 2427, 2438 (2014);

see also Virginia

EPA,

134 S. Ct. 418 (2013),

Pac. Legal Found.

EPA,

134 S. Ct. 418 (2013), and

CRR,

134 S. Ct. 468 (2013) (all denying cert.). Thus, the Supreme Court did not disturb the D.C. Circuit's holding that affirmed the 2009 Endangerment Finding.

D. U.S. Aircraft Regulations and the International Community

The EPA and the FAA traditionally work within the standard-setting process of ICAO's Committee on Aviation Environmental Protection (CAEP or the Committee) to establish international emission standards and related requirements, which individual nations later adopt into domestic law in fulfillment of their obligations under the Convention on International Civil Aviation (Chicago Convention). Historically, under this approach, international emission standards have first been adopted by ICAO, and subsequently the EPA has initiated rulemakings under CAA section 231 to establish domestic standards that are at least as stringent as ICAO's standards. This approach has been affirmed as a reasonable way to implement the Agency's duties under CAA section 231 by the U.S. Court of Appeals for the D.C. Circuit.

Nat'l Ass'n of Clean Air Agencies (NACAA)

EPA,

489 F.3d 1221, 1230-32 (D.C. Cir. 2007). After EPA promulgates aircraft engine emissions standards, CAA section 232 requires the FAA to issue regulations to ensure compliance with these standards when issuing certificates under its authority under Title 49 of the United

States Code. These final endangerment and cause or contribute findings for aircraft GHG emissions are in preparation for this domestic emissions standards rulemaking process.

1. International Regulations and U.S. Obligations

The EPA has worked with the FAA since 1973, and later with ICAO, to develop domestic and international standards and other recommended practices pertaining to aircraft engine emissions. ICAO is a United Nations (UN) specialized agency, established in 1944 by the Chicago Convention, “in order that international civil aviation may be developed in a safe and orderly manner and that international air transport services may be established on the basis of equality of opportunity and operated soundly and economically.”

ICAO sets international standards and regulations for aviation safety, security, efficiency, capacity, and environmental protection and serves as the forum for cooperation in all fields of international civil aviation. ICAO works with the Chicago Convention's member states and global aviation organizations to develop international Standards and Recommended Practices (SARPs), which member states reference when developing their legally enforceable national civil aviation regulations. The United States is currently one of 191 participating ICAO member states.

34 35

ICAO, 2006:

Convention on International Civil Aviation, Ninth Edition,

Document 7300/9, 114 pp. Available at:

http://www.icao.int/publications/Documents/7300_9ed.pdf

(last accessed April 20, 2016).

Members of ICAO's Assembly are generally termed member states or contracting states. These terms are used interchangeably throughout this preamble.

There are currently 191 contracting states according to ICAO's Web site:

www.icao.int

(last accessed April 8, 2016).

In the interest of global harmonization and international air commerce, the Chicago Convention urges its member states to collaborate in securing the highest practicable degree of uniformity in regulations, standards, procedures and organization. The Chicago Convention also recognizes that member states may adopt standards that are more stringent than those agreed upon by ICAO. Any member state which finds it impracticable to comply in all respects with any international standard or procedure, or that deems it necessary to adopt regulations or practices differing in any particular respect from those established by an international standard, is required to give immediate notification to ICAO of the differences between its own practice and that established by the international standard.

ICAO, 2006:

Doc 7300-Convention on International Civil Aviation, Ninth Edition,

Document 7300/9, 114 pp. Available at

http://www.icao.int/publications/Documents/7300_9ed.pdf

(last accessed April 8, 2016).

ICAO's work on the environment focuses primarily on those problems that benefit most from a common and coordinated approach on a worldwide basis, namely aircraft noise and engine emissions. SARPs for the certification of aircraft noise and aircraft engine emissions are covered by Annex 16 of the Chicago Convention. To continue to address aviation environmental issues, in 2004, ICAO established three environmental goals: (1) Limit or reduce the number of people affected by significant aircraft noise; (2) limit or reduce the impact of aviation emissions on local air quality; and (3) limit or reduce the impact of aviation GHG emissions on the global climate.

The Chicago Convention has a number of other features that govern international commerce. First, member states that wish to use aircraft in international transportation must adopt emissions standards and other recommended practices that are at least as stringent as ICAO's standards. Member states may ban the use of any aircraft within their airspace that does not meet ICAO standards.

Second, the Chicago Convention indicates that member states are required to recognize the airworthiness certificates of any state whose standards are at least as stringent as ICAO's standards.

Third, to ensure that international commerce is not unreasonably constrained, a member state which elects to adopt more stringent domestic emission standards is obligated to notify ICAO of the differences between its standards and ICAO standards.

ICAO, 2006:

Convention on International Civil Aviation, Article 87, Ninth Edition,

Document 7300/9, 114 pp. Available at

http://www.icao.int/publications/Documents/7300_9ed.pdf

(last accessed April 8, 2016).

ICAO, 2006:

Convention on International Civil Aviation, Article 33, Ninth Edition,

Document 7300/9, 114 pp. Available at

http://www.icao.int/publications/Documents/7300_9ed.pdf

(last accessed April 8, 2016).

ICAO, 2006:

Convention on International Civil Aviation, Article 38, Ninth Edition,

Document 7300/9, 114 pp. Available at

http://www.icao.int/publications/Documents/7300_9ed.pdf

(last accessed April 8, 2016).

ICAO's CAEP, which consists of members and observers from states, intergovernmental and non-governmental organizations representing aviation industry and environmental interests, undertakes ICAO's technical work in the environmental field. The Committee is responsible for evaluating, researching, and recommending measures to the ICAO Council that address the environmental impacts of international civil aviation. CAEP's terms of reference indicate that “CAEP's assessments and proposals are pursued taking into account: Technical feasibility; environmental benefit; economic reasonableness; interdependencies of measures (for example, among others, measures taken to minimize noise and emissions); developments in other fields; and international and national programs.”

The ICAO Council reviews and adopts the recommendations made by CAEP. It then reports to the ICAO Assembly, the highest body of the Organization, where the main policies on aviation environmental protection are adopted and translated into Assembly Resolutions. If ICAO adopts a CAEP proposal for a new environmental standard, it then becomes part of ICAO standards and recommended practices (Annex 16 to the Chicago Convention).

41 42

ICAO: CAEP Terms of Reference. Available at

http://www.icao.int/environmental-protection/Pages/Caep.aspx#ToR

(last accessed April 27, 2016).

ICAO, 2008:

Aircraft Engine Emissions,

International Standards and Recommended Practices, Environmental Protection, Annex 16, Volume II, Third Edition, July, 110 pp. Available at

http://www.icao.int/publications/catalogue/cat_2016_en.pdf

(last accessed April 8, 2016). The ICAO Annex 16 Volume II is found on page 19 of the ICAO Products & Services 2016 catalog and is copyright protected; Order No. AN16-2.

CAEP develops new emission standards based on an assessment of the technical feasibility, cost, and environmental benefit of potential requirements.

At CAEP meetings, the United States is represented by the FAA and plays an active role.

The EPA has historically been a principal participant in various ICAO/CAEP working groups and other international venues, assisting and advising FAA on aviation emissions, technology, and environmental policy matters. In turn, the FAA assists and advises the EPA on aviation environmental issues, technology and certification matters.

Pursuant to the President's memorandum of August 11, 1960 (and related Executive Order No. 10883 from 1960), the Interagency Group on International Aviation (IGIA) was established to facilitate coordinated recommendations to the Secretary of State on issues pertaining to international aviation. The DOT/FAA is the chair of IGIA, and as such, the FAA represents the U.S. on environmental matters at CAEP.

The first international standards and recommended practices for aircraft engine emissions were recommended by CAEP's predecessor, the Committee on Aircraft Engine Emissions (CAEE), and

adopted by ICAO in 1981.

These standards limited aircraft engine emissions of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NO

). The 1981 standards applied to newly manufactured engines, which are those engines built after the effective date of the regulations—also referred to as in-production engines. In 1993, ICAO adopted a CAEP/2 proposal to tighten the original NO

standard by 20 percent and amend the test procedures.

These 1993 standards applied both to newly certified turbofan engines, which are those engine models that received their initial type certificate after the effective date of the regulations—also referred to as newly certified engines or new engine designs—and to in-production engines, but with different effective dates for newly certified engines and in-production engines. In 1995, CAEP/3 recommended a further tightening of the NO

standards by 16 percent and additional test procedure amendments, but in 1997 the ICAO Council rejected this stringency proposal and approved only the test procedure amendments. At the CAEP/4 meeting in 1998, the Committee adopted a similar 16 percent NO

reduction proposal, which ICAO approved in 1998. The CAEP/4 standards applied only to new engine designs certified (or newly certified engines) after December 31, 2003 (

i.e.,

unlike the CAEP/2 standards, the CAEP/4 requirements did not apply to in-production engines). In 2004, CAEP/6 recommended a 12 percent NO

reduction, which ICAO approved in 2005.

46 47

The CAEP/6 standards applied to new engine designs certified after December 31, 2007. In 2010, CAEP/8 recommended a further tightening of the NO

standards by 15 percent for new engine designs certified after December 31, 2013.

48 49

The Committee also recommended that the CAEP/6 standards be applied to in-production engines (eliminating the production of CAEP/4 compliant engines with the exception of spare engines), and ICAO approved these recommendations in 2011.

ICAO, 2008:

Aircraft Engine Emissions: Foreword,

International Standards and Recommended Practices, Environmental Protection, Annex 16, Volume II, Third Edition, July, 110 pp. Available at

http://www.icao.int/publications/catalogue/cat_2016_en.pdf

(last accessed April 8, 2016). The ICAO Annex 16 Volume II is found on page 19 of the ICAO Products & Services 2016 catalog and is copyright protected; Order No. AN16-2.

CAEP conducts its work over a period of years. Each work cycle is numbered sequentially and that identifier is used to differentiate the results from one CAEP to another by convention. The first technical meeting on aircraft emission standards was CAEP's successor,

i.e.,

CAEE. The first meeting of CAEP, therefore, is referred to as CAEP/2.

CAEP/5 did not address new aircraft engine emission standards.

ICAO, 2008:

Aircraft Engine Emissions,

Annex 16, Volume II, Third Edition, July 2008, Amendment 5 effective on July 11, 2005, 110 pp. Available at

http://www.icao.int/publications/catalogue/cat_2016_en.pdf

(last accessed April 8, 2016). The ICAO Annex 16 Volume II is found on page 19 of the ICAO Products & Services 2016 catalog and is copyright protected; Order No. AN16-2.

CAEP/7 did not address new aircraft engine emission standards.

ICAO, 2010:

Committee on Aviation Environmental Protection (CAEP), Report of the Eighth Meeting, Montreal, February 1-12, 2010,

CAEP/8-WP/80 Available in Docket EPA-HQ-OAR-2010-0687.

ICAO, 2014:

Aircraft Engine Emissions,

Annex 16, Volume II, Third Edition, July 2008, Amendment 8, 108 pp. CAEP/8 corresponds to Amendment 7 effective on July 18, 2011. Available at

http://www.icao.int/publications/catalogue/cat_2016_en.pdf

(last accessed April 8, 2016). The ICAO Annex 16 Volume II is found on page 19 of the ICAO Products & Services 2016 catalog and is copyright protected; Order No. AN16-2/E/11.

2. The International Civil Aviation Organization's Reasons for Addressing Aircraft GHG Emissions

In October 2010, the 37th Assembly (Resolution A37-19) of ICAO requested the development of an ICAO CO

emissions standard.

The Resolution provided a framework towards the achievement of an environmentally sustainable future for international aviation. With this Resolution, the ICAO Assembly agreed to a global aspirational goal for international aviation of improving annual fuel efficiency by two percent up to the year 2050, and stabilizing CO

emissions at 2020 levels.

Reducing climate impacts of international aviation is a critical element of ICAO's strategic objective of achieving environmental protection and sustainable development of air transport. ICAO is currently pursuing a comprehensive set of measures to reduce aviation's climate impact, including lower-carbon alternative fuels, CO

emissions technology-based standards, operational improvements, and market based measures. The development and adoption of a CO

emissions standard is an important part of ICAO's comprehensive set of measures.

A consolidated statement of continuing policies and practices related to environmental protection (known as Assembly Resolutions) is revised and updated by the Council every three years for adoption by the ICAO Assembly. ICAO, 2010:

Resolutions Adopted by the Assembly, 37th Session, Montreal, September 29-October 8, 2010,

Provisional Edition, November 2010.

The global aspirational goal for international aviation of improving annual fuel efficiency by 2 percent is for the annual international civil aviation in-service fleet. Fuel efficiency is measured on the basis of the volume of fuel used per revenue tonne kilometer performed. ICAO CAEP, 2009:

Aspirational Goals and Implementation Options,

Working Paper HLM-ENV/09-WP/5, 5 pp. Available at

http://www.icao.int/Meetings/AMC/MA/High%20Level%202009/hlmenv_wp005_en.pdf

(last accessed April 8, 2015).

3. EPA's Regulation of Aircraft Emissions and the Relationship of the Final Endangerment and Cause or Contribute Findings to International Aircraft Standards

As required by the CAA, the EPA has been engaged in reducing harmful air pollution from aircraft engines for over 40 years, regulating gaseous exhaust emissions, smoke, and fuel venting from aircraft engines.

We have periodically revised these regulations. In a 1997 rulemaking, for example, we made our emission standards and test procedures more consistent with those of ICAO's CAEP for turbofan engines used in commercial aviation with rated thrusts greater than 26.7 kilonewtons.

These ICAO requirements are generally referred to as CAEP/2 standards.

The 1997 rulemaking included new NO

emission standards for newly manufactured commercial turbofan engines (as described earlier, those engines built after the effective date of the regulations that were already certified to pre-existing standards—also referred to as in-production engines)

and for newly certified commercial turbofan engines (as described earlier, those engine models that received their initial type certificate after the effective date of the regulations—also referred to as new engine designs).

It also included a CO emission standard for in-production commercial turbofan engines.

In 2005, we promulgated more stringent NO

emission standards for newly certified commercial turbofan

U.S. EPA, 1973:

Emission Standards and Test Procedures for Aircraft; Final Rule,

38 FR 19088 (July 17, 1973).

U.S. EPA, 1997:

Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test rocedures; Final Rule,

62 FR 25355 (May 8, 1997).

The full CAEP membership meets every three years and each session is denoted by a numerical identifier. For example, the second meeting of CAEP is referred to as CAEP/2, and CAEP/2 occurred in 1994.

This does not mean that in 1997 we promulgated requirements for the re-certification or retrofit of existing in-use engines.

In the existing EPA regulations, 40 CFR part 87, newly certified aircraft engines are described as engines of a type or model of which the date of manufacture of the first individual production model was after the implementation date. Newly manufactured aircraft engines are characterized as engines of a type or model for which the date of manufacturer of the individual engine was after the implementation date.

U.S. EPA, 1997:

Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures; Final Rule,

62 FR 25355 (May 8, 1997).

engines.

That final rule brought the U.S. standards closer to alignment with ICAO CAEP/4 requirements that became effective in 2004. In 2012, we issued more stringent two-tiered NO

emission standards for newly certified and in-production commercial and non-commercial turbofan aircraft engines, and these NO

standards align with ICAO's CAEP/6 and CAEP/8 requirements that became effective in 2013 and 2014, respectively.

60 61

The EPA's actions to regulate certain pollutants emitted from aircraft engines come directly from the authority in section 231 of the CAA, and we have aligned the U.S. emissions requirements with those promulgated by ICAO. All of these previous emission standards have generally been considered anti-backsliding standards (most aircraft engines meet the standards), which are technology-following.

U.S. EPA, 2005:

Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures; Final Rule,

70 FR 69664 (November 17, 2005).

U.S. EPA, 2012:

Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures; Final Rule,

77 FR 36342 (June 18, 2012).

While ICAO's standards were not limited to “commercial” aircraft engines, our 1997 standards were explicitly limited to commercial engines, as our finding that NO

and carbon monoxide emissions from aircraft engines cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare was so limited. See 62 FR 25358 (May 8, 1997). In the 2012 rulemaking, we expanded the scope of that finding and of our standards pursuant to CAA section 231(a)(2)(A) to include such emissions from both commercial and non-commercial aircraft engines based on the physical and operational similarities between commercial and noncommercial civilian aircraft and to bring our standards into full alignment with ICAO's.

In addressing CO

emissions, ICAO has moved to regulating a whole aircraft. ICAO explained its decision to regulate pollutant emissions from the whole aircraft in a 2013 ICAO circular.

Several factors are considered when addressing whole-aircraft CO

emissions, as CO

emissions are influenced by aerodynamics, weight, and engine technology. Since the aircraft-specific characteristics of aerodynamics and weight affect fuel consumption, they ultimately affect CO

engine exhaust emissions. Rather than viewing CO

as a measurable emission from the engine alone, ICAO addresses CO

emissions as an aircraft-specific characteristic based on fuel consumption.

ICAO, 2013:

CAEP/9 Agreed Certification Requirement for the Aeroplane CO

Emissions Standard,

Circular (Cir) 337, 40 pp, AN/192. Available at

http://www.icao.int/publications/catalogue/cat_2016_en.pdf

(last accessed April 8, 2016). The ICAO Circular 337 is found on page 87 of the ICAO Products & Services 2016 catalog and is copyright protected; Order No. CIR337.

The EPA has worked diligently over the past six years within the ICAO/CAEP process on a range of technical issues regarding aircraft CO

emission standards. The 2015 ANPR discussed the issues arising from those international proceedings and requested public comment on a variety of issues to assist the Agency in developing its position with regard to these issues, to help ensure transparency and obtain views on aircraft engine GHG emission standards that it might potentially adopt under the CAA.

As described in the 2015 ANPR, in 2013 CAEP agreed on a metric

to compare CO

emissions from aircraft. The CO

metric value is a comparative metric meant to differentiate between generations of aircraft and to equitably capture improvements in aerospace technology that contribute to a reduction in the airplane CO

emissions. The CO

metric is not intended for use as a direct measure of CO

emissions rates or operational fuel burn, rather it is a comparative measure of technology on different aircraft.

The CO

metric is the average of three cruise test points normalized by a dimensionless parameter representing aircraft fuselage size. The units of the metric value are kilograms of fuel burned per kilometer flown. However, because the metric is a normalized value it cannot be used to estimate operational fuel burn or emission rates of aircraft. The metric value is described in detail in both ICAO Circular 337 and in section D of the 2015 ANPR. ICAO, 2013:

CAEP/9 Agreed Certification Requirement for the Aeroplane CO

Emissions Standard,

Circular (Cir) 337, 40 pp., AN/192, Available at

http://www.icao.int/publications/catalogue/cat_2016_en.pdf

(last accessed April 27, 2016). The ICAO Circular 337 is found on page 87 of the catalog and is copyright protected; Order No. CIR337.

Using this metric, CAEP considered and analyzed 10 different stringency levels for both in-production and new type standards, comparing aircraft with a similar level of technology on the same stringency level. These levels were generically referred to numerically from “1” as the least stringent to “10” as the most stringent, which correspond to the upper and lower lines of constant technology, respectively, from the 2015 ANPR. The 2015 ANPR described the range of stringency levels under consideration at CAEP as falling into three categories as follows: (1) CO

stringency levels that could impact

only the oldest, least efficient aircraft in-production around the world, (2) middle range CO

stringency levels that could impact many aircraft currently in-production and comprising much of the current operational fleet, and (3) CO

stringency levels that could impact aircraft that have either just entered production or are in final design phase but will be in-production by the time the international CO

standards becomes effective.

As described in the 2015 ANPR, the aircraft shown in [Figure II.1 and II.2] are in-production and current in-development. These aircraft could be impacted by an in-production standard in that, if they were above the standard, they would need to either implement a technology response or go out of production. For a new type only standard there will be no regulatory requirement for these aircraft to respond.

80 FR at 37797.

At its meeting in February of 2016, CAEP agreed on an initial set of international standards to regulate CO

emissions from aircraft.

It was agreed that these international standards should apply to both new type and in-production aircraft. The applicability date for the in-production standard was agreed to be later than for the new type standard. CAEP explained that this will allow manufacturers and certification authorities additional preparation time to accommodate the standards. The new type and in-production stringency levels for smaller and larger aircraft were agreed to be set at different levels to reflect the range of technology being used and the availability of new fuel burn reduction technologies that vary across aircraft of differing size and weight. Table II.1 provides a brief overview of the applicability dates and stringency levels of the standards agreed to at ICAO/CAEP. As described earlier, CAEP considered and analyzed 10 different stringency levels for both in-production and new type standards (from 1 as the least stringent to 10 as the most stringent).

Further, the EPA anticipates that the 39th ICAO Assembly will approve these CO

emissions standards in October 2016, and that subsequently, ICAO will formally adopt these CO

emissions standards in March 2017.

Table II.1—Stringency Levels and Applicability Dates for ICAO/CAEP CO

Emission Standards

Aircraft MTOM thresholds (kg)

New type aircraft

maximum permitted CO

metric value

In-production aircraft

maximum

permitted

metric

value

Stringency Level

>5,700 to <60,000

Horizontal Transition

60,000 to ~70,000

> ~70,000

8.5

Applicability Date

Application for a new type certificate or a change to an existing type certificate

2020

(2023 for planes with less than 19 seats)

2023

Production Cut Off

n/a

2028

Equation of ICAO Stringency Option #5:

= 10

−

2.73780

(0.681310*

(

))

(

−

0.0277861*(

10(

))

)

Equation of ICAO Stringency Option #3:

= 10

−

2.57535

(0.609766*

10(

))+

(

−

0.0191302*(

10(

))

)

Equation of New Type transition—60,000 to 70,395 kg:

= 0.764

Equation of In-production transition—60,000 to 70,107 kg:

= 0.797

Equation of ICAO Stringency Option #8.5:

= 10

−

2.57535

0.609766*

10(

))+

(

−

0.0191302*(

10(

))

)

Equation of ICAO Stringency Option #7:

= 10

−

1.39353

(

−

0.020517*

10(

))+

(

0.0593831*(

10(

))

)

Figures

II.1 and II.2 show a graphical depiction of both the new type and in-production standards compared against the lines of constant technology described in the 2015 ANPR and CO

metric value levels of current (as of February 2016) in-production and in-development

aircraft. The aircraft data shown were generated by the EPA using a commercially available aircraft modeling tool called PIANO.

It should be noted that a number of the aircraft currently shown as in-production are expected to go out of production and be replaced by known in-development aircraft prior to both the new type and the in-production CO

standards going into effect internationally.

“In Development” aircraft shown in Figures II.1 and II.2 are the aircraft that were in development by manufacturers at the time the 2015 ANPR was published.

Stringency lines above and below 60,000 kilograms (MTOM) are connected by a horizontal transition starting at 60,000 kilograms (MTOM) and continuing right (increasing mass) until it intersects with the next level.

Aircraft that are currently in-development but will be in production by the applicability dates. These could be new types or significant partial redesigned aircraft.

PIANO (Project Interactive Analysis and Optimization), Aircraft Design and Analysis Software by Dr. Dimitri Simos, Lissys Limited, UK, 1990-present; Available at

www.piano.aero

(last accessed April 8, 2016). This is a commercially available aircraft design and performance software suite used across the industry and academia. This model contains non-manufacturer provided estimates of performance of various aircraft.

BILLING CODE 6560-50-P

ER15AU16.000

ER15AU16.001

BILLING CODE 6560-50-C

In this final action, the EPA is promulgating findings under section 231(a)(2) that emissions of the six well-mixed GHGs from certain classes of engines used in covered aircraft cause or contribute to endangering air pollution. The EPA is not yet issuing proposed or final emission standards, nor is the EPA taking final action that prejudges what future standards will be. Instead, the EPA's final endangerment and cause or contribute findings for aircraft GHG emissions are in preparation for a subsequent, expected domestic

rulemaking process to adopt future GHG emissions standards. If the ICAO Assembly, in October 2016, approves the final CO

standards and subsequently ICAO formally adopts the final CO

standards in March 2017, the EPA's standards will need to be at least as stringent as the ICAO CO

aircraft standards for the United States to meet its treaty obligations under the Chicago Convention. As a result of these positive findings, the EPA is obligated under section 231 of the CAA to set emission standards applicable to GHG emissions from the classes of aircraft engines included in the contribution finding, no matter the outcome of ICAO's future actions in October 2016 and March 2017.

III. Legal Framework for This Action

The EPA has previously made an endangerment finding for GHGs under Title II of the CAA, in the 2009 Endangerment Finding for section 202(a) source categories. In the 2009 Endangerment Finding, the EPA explained its legal framework for making an endangerment finding under section 202(a) of the CAA (74 FR 18886, 18890-94 (April 24, 2009), and 74 FR 66496, 66505-10 (December 15, 2009)). The text in section 202(a) that was the basis for the 2009 Endangerment Finding addresses “the emission of any air pollutant from any class or classes of new motor vehicles or new motor vehicle engines, which in [the Administrator's] judgment cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare.” Similarly, section 231(a)(2)(A) concerns “the emission of any air pollutant from any class or classes of aircraft engines which in [the Administrator's] judgment causes, or contributes to, air pollution which may reasonably be anticipated to endanger public health or welfare.” Thus, the text of the CAA section concerning aircraft emissions in section 231(a)(2)(A) mirrors the text of CAA section 202(a) that was the basis for the 2009 Endangerment Finding.

The EPA's approach in the 2009 Endangerment Finding (described below in sections III.A and III.B) was affirmed by the U.S. Court of Appeals for the D.C. Circuit in

Coalition for Responsible Regulation, Inc.

EPA,

684 F.3d 102 (D.C. Cir. 2012),

reh'g denied

2012 U.S. App. LEXIS 26313, 26315, 25997 (D.C. Cir. 2012) (

CRR

). In particular, the D.C. Circuit ruled that the 2009 Endangerment Finding (including the Agency's denial of petitions for reconsideration of that Finding) was not arbitrary or capricious, was consistent with the U.S. Supreme Court's decision in

Massachusetts

EPA

and the text and structure of the CAA, and was adequately supported by the administrative record.

CRR,

684 F.3d at 116-128. The D.C. Circuit found that the EPA had based its decision on “substantial scientific evidence” and noted that the EPA's reliance on major scientific assessments was consistent with the methods that decision-makers often use to make a science-based judgment.

Id.

at 120-121. Petitions for

certiorari

were filed in the Supreme Court, and the Supreme Court granted six of those petitions but “agreed to decide only one question: `Whether EPA permissibly determined that its regulation of greenhouse gas emissions from new motor vehicles triggered permitting requirements under the Clean Air Act for stationary sources that emit greenhouse gases.' ”

Utility Air Reg. Group

EPA,

134 S. Ct. 2427, 2438 (2014); see also

Virginia

EPA,

134 S. Ct. 418 (2013),

Pac. Legal Found.

EPA,

134 S. Ct. 418 (2013), and

CRR,

134 S. Ct. 468 (2013) (all denying cert.). Thus, the Supreme Court did not disturb the D.C. Circuit's holding that affirmed the 2009 Endangerment Finding. Accordingly, the Agency finds that it is reasonable to use that same approach under section 231(a)(2)(A)'s similar endangerment text, and as explained in the following discussion, is acting consistently with that judicially sanctioned framework for purposes of this final section 231 finding.

Two provisions of the CAA govern this final action. Section 231(a)(2)(A) sets forth a two-part predicate for regulatory action under that provision: Endangerment and cause or contribute. Section 302 of the Act contains definitions of the terms “air pollutant” and “welfare” used in section 231(a)(2)(A). These statutory provisions are discussed below.

A. Section 231(a)(2)(A)—Endangerment and Cause or Contribute

As noted above, section 231(a)(2)(A) of the CAA (like section 202(a)) calls for the Administrator to exercise her judgment and make two separate determinations: first, whether the relevant kind of air pollution—here, the six well-mixed GHGs—may reasonably be anticipated to endanger public health or welfare, and second, whether emissions of any air pollutant from classes of the sources in question (aircraft engines under section 231 and new motor vehicles or engines under section 202) cause or contribute to this air pollution.

See CRR,

684 F.3d at 117 (explaining two-part analysis under section 202(a)).

The Administrator interprets the two-part test required under section 231(a)(2)(A) as being the same as that explained in the 2009 Endangerment Finding.

See

74 FR 66505-06. As in the section 202(a) context, this analysis entails a scientific judgment by the Administrator about the potential risks posed by GHG emissions to public health and welfare.

See CRR,

684 F.3d at 117-118.

When agencies such as the EPA make determinations based on review of scientific data within their technical expertise, those decisions are given an “extreme degree of deference” by the courts. As the D.C. Circuit noted in reviewing the 2009 Endangerment Finding, “although we perform a searching and careful inquiry into the facts underlying the agency's decisions, we will presume the validity of the agency action as long as a rational basis for it is presented.”

CRR,

684 F.3d at 120 (internal citations and marks omitted).

In making this scientific judgment, the Administrator is guided by five principles. First, the Administrator is required to protect public health and welfare. She is not asked to wait until harm has occurred but instead must be ready to take regulatory action to prevent harm before it occurs.

The Administrator is thus to consider both current and future risks.

See id.

at 121-122.

Second, the Administrator is to exercise judgment by weighing risks, assessing potential harms, and making reasonable projections of future trends and possibilities. It follows that when exercising her judgment the Administrator balances the likelihood and severity of effects. This balance involves a sliding scale: on one end the severity of the effects may be significant, but the likelihood low, while on the other end the severity may be less significant, but the likelihood high.

At different points along this scale, the Administrator is permitted to find endangerment. Accordingly, the Administrator need not set a precise or minimum threshold of risk or harm as part of making an endangerment finding, but rather may base her determination on “ `a lesser risk of greater harm . . . or a greater risk of lesser harm' or any combination in between.”

CRR,

684 F.3d at 123 (quoting

Ethyl Corp.

EPA,

541 F.2d, 1, 18 (D.C. Cir. 1976)).

See id.

at 122-123 (noting that the § 202(a)(1) inquiry “necessarily entails a case-by-case, sliding scale approach” because endangerment is “ `composed of reciprocal elements of risk and harm, or probability and severity' ” (quoting

Ethyl Corp.

EPA,

541 F.2d, 1, 18 (D.C. Cir. 1976)).

Third, because scientific knowledge is constantly evolving, the Administrator may be called upon to make decisions while recognizing the uncertainties and limitations of the data or information available, as risks to public health or

welfare may involve the frontiers of scientific or medical knowledge.

At the same time, the Administrator must exercise reasoned decision making, and avoid speculative inquiries.

See

id.

at 121-122.

Fourth, the Administrator is to consider the cumulative impact of sources of a pollutant in assessing the risks from air pollution, and is not to look only at the risks attributable to a single source or class of sources. We additionally note that in making an endangerment finding, the Administrator is not limited to considering only those impacts that can be traced to the amount of air pollution directly attributable to the subject source classes. Such an approach would collapse the two prongs of the test by requiring that any climate change impacts upon which an endangerment determination is made result solely from the GHG emissions of aircraft.

See

74 FR at 66542 (explaining the same point in the context of analogous language in section 202(a)). Similarly, the Administrator is not, in making the endangerment and cause or contribute findings, to consider the effect of emissions reductions from the resulting standards.

The threshold endangerment and cause or contribute criteria are separate and distinct from the standard setting criteria that apply if the threshold findings are met, and they serve a different purpose. Indeed, the more serious the endangerment to public health and welfare, the more important it may be that action be taken to address the actual or potential harm even if no one action alone can solve the problem, and a series of actions is called for.

As the D.C. Circuit explained in reviewing the 2009 Endangerment Finding under analogous language in section 202(a): “At bottom, § 202(a)(1) requires EPA to answer only two questions: whether particular `air pollution'—here, greenhouse gases—`may reasonably be anticipated to endanger public health or welfare,' and whether motor-vehicle emissions `cause, or contribute to' that endangerment.”

CRR,

648 F.3d at 117.

Fifth, the Administrator is to consider the risks to all parts of our population, including those who are at greater risk for reasons such as increased susceptibility to adverse health and welfare effects. If vulnerable subpopulations are especially at risk, the Administrator is entitled to take that point into account in deciding the question of endangerment. Here too, both likelihood and severity of adverse effects are relevant. As explained previously in the 2009 Endangerment Finding and as reiterated below for this section 231 finding, vulnerable subpopulations face serious health and welfare risks as a result of climate change.

As the Supreme Court recognized in

Massachusetts

EPA,

549 U.S. at 534, the EPA may make an endangerment finding despite the existence of “some residual uncertainty” in the scientific record.