The Legal Character of the Paris Agreement

From start to finish, the question of legal form or character was central to the Paris negotiations. The Paris Agreement is a treaty within the definition of the Vienna Convention on the Law of Treaties, but not every provision of the agreement creates a legal obligation. It contains a mix of mandatory and non‐mandatory provisions relating to parties’ mitigation contributions, as well as to the other elements of the Durban Platform, including adaptation and finance. One cannot definitively say how much the legally binding character of the Paris Agreement matters. Making the agreement legally binding may provide a greater signal of commitment and greater assurance of compliance. But transparency, accountability and precision can also make a significant difference, and legal bindingness can be a double‐edged sword if it leads States not to participate or to make less ambitious commitments. Thus, the issue of legal character, though important, is only one factor in assessing the significance of the Paris outcome.