US Exit From the Paris Agreement Takes Effect, Leaving the Largest Historical Emitter Outside the Treaty

The United States formally left the Paris Agreement on January 27, 2026. The withdrawal took effect one year after the United Nations received the formal notification, which President Donald Trump ordered on his first day back in office in January 2025. The UN had confirmed the effective date shortly after receiving the notice, and the New York Times reported on January 27 that the exit was complete. As a non-party, the United States is no longer bound by the agreement's obligations to submit nationally determined contributions, to report under the enhanced transparency framework or to participate in the five-year global stocktake.

The NDC submitted by the Biden administration in December 2024, which set a target of cutting net greenhouse gas emissions by 61% to 66% below 2005 levels by 2035, no longer has formal standing under the treaty. The United States remains a party to the UN Framework Convention on Climate Change, the 1992 treaty under which the Paris Agreement sits, unless it withdraws from that as well. The administration has already ended US participation in several climate finance initiatives.

The withdrawal is one part of a broader shift in US energy and climate policy. At the same time, US electricity demand is rising after two decades of little growth, driven by data centers, manufacturing and electrification. For US energy exporters, the withdrawal has limited direct effect on trade. Analysts have noted that the absence of the United States affects the balance of negotiations, particularly on finance and on language about fossil fuels. Many large US companies have their own climate targets, often set through the Science Based Targets initiative.

Several US states have continued to set their own targets and programs. The key questions are whether the United States participates in COP31 in Antalya in November 2026, whether it moves to leave the UNFCCC, and how state-level policies and corporate procurement develop in the absence of a federal commitment.