US-proofing the Paris Climate Agreement

What can be done if a future US President withdraws from the Paris Climate Agreement? This is a critical question for an agreement which relies on universal participation for legitimacy. The US can and likely will ratify the Paris Agreement via a presidential-executive agreement. However, this could be easily reversed by a future President or an antagonistic Congress. A non-party US operating outside of the Paris climate architecture is a real threat, especially given Republican opposition to international climate policy. This article explores both what tools are available for addressing a non-party US in any climate agreement and what the Paris Agreement in particular can do. The Paris Agreement is extremely vulnerable to the withdrawal of the US, or any other major party. It possesses no non-party measures, although it can be amended to help avoid this Achilles heel. Through amendments to Article 6 a market link between subnational states in a renegade US and international carbon markets could be created. Ideally, a more semi-global approach with punitive carbon border tax adjustments could be taken to help US-proof an alternative climate agreement. The Paris Agreement will be fatally susceptible to a US dropout unless amendments to the treaty are made. Relying on the good will of a single president is short-sighted. Longer-term climate governance needs to take seriously the threat of non-parties, particularly if they are superpowers.Policy relevanceThis article explores how to craft an effective climate treaty without US ratification, including through reforms to the Paris Agreement. While the US is likely to be able to be able legally adopt the Paris Agreement through a presidential-executive agreement there is a distinct possibility of the US withdrawing and repealing such an agreement due to a change in president. This article suggests that the Paris Agreement is vulnerable to such an occurrence and thus the insights of this research are both timely and relevant to delegations and others involved with the UNFCCC. It will be of use to domestic US actors, as well as international negotiators and scholars in dealing with a non-party US and non-parties in general.