In July 2023, the International Maritime Organization (IMO) resolved to reduce international shipping’s greenhouse gas emissions to net zero “by or around, i.e., close to” 2050. There is a long-running debate about whether the sector should decarbonize and how it could do so in a way that is equitable for states and the shipping industry. This Article is the first to normatively define shipping’s fair share of the overall climate mitigation burden using principles of international environmental law. It refers to the IMO’s institutional rules and practice to identify relevant principles, evaluates emission reduction pathways based on the sector’s technological potential, and determines that its fair share would be its highest possible ambition in light of its unique capacity to mitigate. The Article ties shipping’s climate goals to a framework of international environmental law, and offers a structure to assess its ambition going forward.

Methane is estimated to be responsible for one-third of the global rise in temperatures from greenhouse gases; it is shorter-lived but much more potent than carbon dioxide. The United States and the European Union (E.U.) launched the Global Methane Pledge at the 2021 United Nations Climate Change Conference (COP26). At COP28’s Global Methane Pledge Ministerial last December, new strategies were announced, including the E.U.’s first-ever adoption of methane regulations and a final rule by the U.S. Environmental Protection Agency to reduce methane from the oil and gas industry. On January 31, 2024, the Environmental Law Institute hosted a panel of experts to analyze these regulations, discuss strategies other countries are employing to reduce emissions, and consider whether these efforts will meet 2030 goals. This Dialogue presents a transcript of that discussion, which has been edited for style, clarity, and space considerations.