U.S. Legal Pathways for Implementing the IMO’s Greenhouse Gas Pricing Plan

• Pages: 86-116
• Date: 01 July 2025
• Published date: 01 July 2025
• Author: Thomas Murray
• Subject Matter: Administrative & Public Law

55 ELR 10438 ENVIRONMENTAL LAW REPORTER JULY/AUGUST 2025

In 2023, the International Maritime Organization

(IMO) adopted its 2023 Greenhouse Gas (GHG)

Strategy, which set the ambitious target of reaching

net-zero emissions from shipping by 2050,1 with chec k-

points at 2030 of at least 20% less emissions, and 2040 of

at least 70% less emissions.2 e ambition of this plan is

enabled by the ambition of its proposed method, an “eco-

nomic element, on the basis of a maritime GHG emissions

1. IMO, Res. MEPC.377(80), at 6, IMO Doc. MEPC 80/17/Add.1 (July 7,

2023) [hereinafter IMO Res. MEPC.377(80)].

2. Id.

AVOIDING ANOTHER KYOTO:

U.S. LEGAL PATHWAYS FOR

IMPLEMENTING THE IMO’S

GREENHOUSE GAS PRICING PLAN

by Thomas Murray

Thomas Murray is a Fox Fellow at the Universidad de San Andrés in Buenos Aires, a

Master’s candidate at the Yale School of the Environment, and a U.S.-Nominated Technical

Expert to the United Nations Framework Convention on Climate Change.

In the next few years, the International Maritime Organization will create the world’s f‌irst greenhouse gas

(GHG) pricing mechanism to reduce emissions from shipping. The United States may be unable to adopt

it legislatively, repeating the events of the Kyoto Protocol. To ease passage, nations agreed to create the

mechanism as an amendment to the existing Convention for the Prevention of Pollution From Ships (MAR-

POL), which a U.S. Secretary of State should be able to unilaterally accept or reject under the expedited

amendment procedure of MARPOL’s implementing legislation. This Article demonstrates the insuff‌iciency of

this strategy, as the procedure is unbounded and the pricing scheme too extraordinar y, such that its usage

may easily run afoul of the nondelegation doctrine and the new “major questions doctrine.” If the amend-

ment instead were implemented by the U.S. Environmental Protection Agency through a Clean Air Act §115

f‌inding, the executive may still be able to accept and implement the scheme, avoiding congressional gridlock.

SUMMARYSUMMARY

pricing mechanism,”3 to be created as an amendment to

the International Convention for the Prevention of Pollu-

tion From Ships (MARPOL) Annex V I.4 To succeed, IMO

negotiators are aiming to craf t an agreement to come into

force by 2027, yet as of mid-2025 an agreement has not

been nalized.

In early April, the IMO’s Marine Environment Protec-

tion Committee agreed to the drafted text of an agree-

ment, to be formally tendered for adoption in October

2025. is text attempts to establish the IMO’s “Net-Zero

Framework” by creating a new fuel standard and a two-

tiered pricing mechanism that will allow ships to either

buy remedial units or sell surplus units, depend ing on their

emissions outputs.5 Yet, rare for the IMO, the draft text

was not agreed to unanimously; key states, including Rus-

3. Id. at 8.

4. See Simone Vitzthum, Greenhouse Gas Regulations: What Are IMO’s Next

Steps?, S (Aug. 22, 2024), https://www.skuld.com/topics/environ-

ment/air-pollution/marpol-annex-vi/greenhouse-gas-regulations-what-are-

imos-next-steps/ (explaining that while the amendment need not necessar-

ily be an amendment to Annex VI, that seems to be the most likely option,

based on the existing proposals).

5. Press Release, IMO, IMO Approves Net-Zero Regulations for Global Ship-

ping (Apr. 11, 2025), https://www.imo.org/en/mediacentre/pressbriengs/

pages/imo-approves-netzero-regulations.aspx.

Author’s Note: I would like to thank the Universidad de San

Andrés, Yale University, and its MacMillan Center for Inter-

national and Area Studies for the Fox Fellowship necessary

to complete this Article. I would also like to thank Prof. Glen

Staszewski for his invitation to present an earlier draft at

the Association of American Law Schools’ New Voices in

Administrative Law section, as well as Profs. William Funk

and Sharon Jacobs for their critical insights on the piece.

The views ref‌lected in the Article express only those of the

author, and do not ref‌lect those of any reviewer, Yale Uni-

versity, nor the United Nations Framework Convention on

Climate Change.

Copyright © 2025 Environmental Law Institute®, Washington, DC. Reprinted with permission from ELR®, http://www.eli.org

JULY/AUGUST 2025 ENVIRONMENTAL LAW REPORTER 55 ELR 10439

sia, Venezuela, and the Gulf States, voted against it, and

the United States and 23 others abstained.6

While the United States under Donald Trump’s Admin-

istration is unlikely to join immediately, some form of the

agreement will likely pass globally, raising the question of

whether the next administration will join and what form

the agreement will take t hen. If the United States does join,

the monumentality of such a decision would not only be

due to it being the world’s rst global, substantive GHG

pricing scheme,7 but also to it setting an important prec-

edent for creation of regulatory schemes in international

waters. However, even if the next administration were

interested, there is no guarantee the U.S. Congress would

approve, bringing the nation down the same path as the

Kyoto Protocol, where an international economic scheme

to curb GHGs was concluded internationally and signed

by the U.S. president but failed to be ratied by Congress,

ultimately leading other States to leave it and damning the

whole scheme into ob scurity.8

e asco of the Kyoto Protocol loomed large over the

Barack Obama Administration during its negotiation

of the Paris Climate Agreement, eventually leading the

president to skip congressional authorization and accept

the agreement through sole executive action, with the

expected parties t aking various sides on the legality of

this action.9 e main, highly contested argument for its

legality was t hat the president already had sucient, exis t-

ing congressional authority to do so, under the Senate’s

ratication of the United Nations Framework Convention

on Climate Change (UNFCCC) and the Global Climate

Protection Act.10

If the IMO GHG pricing scheme is in a similar posi-

tion, a future president could try to use the same strateg y of

relying on existing congressional authorization. Similar to

the acceptance of the Paris Agreement being grounded in

6. Hussein Al-Khalisy et al., IMO Approves Two-Tier GHG Pricing Mechanism,

A M (Apr. 11, 2025), https://www.argusmedia.com/en/news-

and-insights/latest-market-news/2677729-imo-approves-two-tier-ghg-pric-

ing-mechanism.

7. e closest example would be the Paris Agreement, but as it did not require

substantive actions to reduce emissions, this Article considers that the pas-

sage of the IMO’s GHG pricing mechanism would be the rst substan-

tive, global GHG reduction instrument. See generally Paris Agreement to

the United Nations Framework Convention on Climate Change, Dec. 12,

2015, U.N. Doc. FCCC/CP/2015/L. 9/Rev/1, T.I.A.S. No. 16-1104 [here-

inafter Paris Agreement].

8. See Amanda M. Rosen, e Wrong Solution at the Right Time: e Failure of

the Kyoto Protocol on Climate Change, 43 P.  P’ 31 (2015) (discussing

the history of the Kyoto Protocol).

9. Compare Steven Groves, e Paris Agreement Is a Treaty and Should Be

Submitted to the Senate, H F. (Mar. 15, 2016), https://www.

heritage.org/environment/report/the-paris-agreement-treaty-and-should-

be-submitted-the-senate, with Center for Biological Diversity, Yes, He Can:

President Obama’s Power to Enter a Legally Binding Agreement Without Wait-

ing for Congress, https://www.biologicaldiversity.org/programs/climate_

law_institute/to_paris_and_beyond/pdfs/YesHeCanFactsheet.pdf. Both

organizations analyze the same agreement, the Paris Climate Agreement,

with the case criteria, the C-175 State Department Circular, but come to

opposite conclusions, which tend to align with their respective anti- and

pro-environmental positions.

10. Harvard Dataverse, Statement Regarding the Paris Agreement, https://data-

verse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/M6E3ER

(last visited June 13, 2025) [hereinafter Paris Cover Memo].

the UNF CCC’s founding treat y,11 the IMO’s GHG pricing

mechanism could rest on the Senate’s ratication of MA R-

POL Annex VI.12 Moreover, Congress has already pa ssed

implementing legislation to Annex VI with a sec tion allow-

ing for a simplied amendment process: the Act to Prevent

Pollution From Ships (APPS), specically §1909(b).13

However, an important aspect of why the Paris Agree-

ment ended up not needing congressional authorization

was its lack of binding, substantive obligations, particu-

larly that it placed no emissions reductions or controls on

any nation that joined.14 While nations were required to

create emissions-reduction plans (“nationally determined

contributions”) and routinely increase their ambitions (the

“ratchet up” mechanism), there was no requirement that

these pla ns be followed.15 As a consequence, the Obama

Administration was able to rest its authority to conclude

such an agreement on the Global Climate Protection Act,

given that this law largely only a llows the executive to for-

mulate and coordinate internat ional climate agreements,

but does not give any specic power to implement require-

ments of those agreements.16

erefore, the IMO’s GHG pricing scheme, as a sub-

stantive mechanism that would require some actions,

would still need to rest on previously delegated congressio-

nal authority to avoid the Kyoto Protocol’s fate, but is too

substantive to use the same legislation as t he Paris Agree-

ment. e APPS amendment route would be the most

natural t, but it may be easily questioned whether this

amendment procedure, simply a few paragraphs seemingly

intended for technical revisions,17 could actually support

the creation of a new regulatory scheme.

Worryingly, these arguments have already been raised

against APPS §1909(b) amendments. In 2012, when the

United States negotiated the North American Emissions

Control Area (ECA) through t he IMO and implemented

it through the §1909(b) procedure, the state of Alask a sued

on the grounds that §1909(b) was too limited for such a

signicant program, which t hus should have been passed as

an Article II tre aty.18 While the district c ourt ruled in favor

of the federal government,19 its rea soning was based on

questiona ble logic20; a nd now, following the U.S. Supreme

11. Id.

12. Protocol of 1997 Amending MARPOL Convention, S. Treaty Doc. No.

108-7, 108th Cong. (2006).

13. APPS, 33 U.S.C. §1909(b) (2008).

14. Paris Agreement, supra note 7, art. 3; see generally Miranda A. Schreurs, e

Paris Climate Agreement and the ree Largest Emitters: China, the United

States, and the European Union, 4 P.  G 219 (2016) (“e

Obama administration moreover worked to shape the Paris Agreement in

such a way that it would not require ratication by the Senate.. .. e

INDCs [intended nationally determined contributions] are non-binding,

aspirational targets, and thus, as interpreted by the Obama administration,

do not need Congressional approval.”).

15. Paris Agreement, supra note 7.

16. Paris Cover Memo, supra note 10.

17. See infra Section I.A.

18. Alaska v. Kerry, 972 F. Supp. 2d 1111 (D. Alaska 2013).

19. Id. at 1150.

20. See John Micheal Allen, e Dangerous Expansion of Executive Treaty Power

in Alaska v. Kerry and the MARPOL Convention, 27 G. I’ E’ L.

R. 497, 504-05 (2014/2015) (describing the key inconsistency—the

judge nds that there are sucient limitations on the Secretary of State’s

Copyright © 2025 Environmental Law Institute®, Washington, DC. Reprinted with permission from ELR®, http://www.eli.org