The Paris Agreement

The Paris Agreement is a 2015 international treaty under the United Nations Framework Convention on Climate Change. Each signatory sets its own emissions reduction targets, called nationally determined contributions, and reports progress on a regular cycle.

Adopted in December 2015 at the twenty-first Conference of the Parties to the UN Framework Convention on Climate Change, the Paris Agreement was the first climate accord to bring nearly every country in the world into a common framework. Earlier efforts, including the Kyoto Protocol of 1997, had imposed binding emissions targets only on developed nations. Paris took a different approach. Each country sets its own emissions reduction target, called a nationally determined contribution, and updates it every five years. The collective goal is to hold global temperature rise well below 2 degrees Celsius above preindustrial levels, with efforts to limit it to 1.5 degrees. The agreement is binding in its procedural requirements but not in its substantive targets. Countries cannot be sanctioned for missing their goals. The United States joined the agreement under President Obama through executive action, an arrangement that allowed it to take effect without Senate ratification. President Trump announced withdrawal in 2017, citing concerns about economic costs and unfair burdens compared to developing countries like China and India. President Biden rejoined in 2021. President Trump withdrew again in 2025. The American experience reflects a deeper question raised by the agreement: whether climate policy is a permanent commitment that should outlast any single administration, or a discretionary policy choice that each elected government may revisit. The Clean Air Act and the Environmental Protection Agency remain the domestic legal machinery through which any climate commitments are actually implemented.