U.S. acceptance of the new climate agreement being negotiated under the United Nations Framework Convention on Climate Change (UNFCCC) may or may not require legislative approval, depending on its contents. U.S. law recognizes several routes for entering into international legal agreements. The president would be on relatively firm legal ground accepting a new climate agreement with legal force, without submitting it to the Senate or Congress for approval, to the extent it is procedurally oriented, could be implemented on the basis of existing law, and is aimed at implementing or elaborating the UNFCCC. On the other hand, if the new agreement establishes legally binding emissions limits or new legally binding financial commitments, this would weigh in favor of seeking Senate or congressional approval. However, the exact scope of the president’s legal authority to conclude international agreements is uncertain, and the president’s decision will likely rest also on political and prudential considerations.

The brief is based on the report, Legal Options for U.S. Acceptance of a New Climate Change Agreement, which provides a fuller legal analysis.