U.S. Lawmakers to Attend COP31 in Turkey Despite Paris Exit

What can the delegation actually do?

Casten urged realism about the limits of the trip. He pointed to a long record of U.S. inconsistency on climate diplomacy — the failure to ratify the 1997 Kyoto Protocol (the Paris deal's predecessor) and the two Paris exits under Trump.

He said it was important not to be naive about that history.

"But I think also there's a real value in us being able to convey to the world, number one, that America has spoken, and number two, that so many of the challenges we face are the same," Casten said.

By "America has spoken," he was referring to the midterm results. The delegation wants foreign governments to know that a large share of American voters and their representatives still back climate action, even if the White House does not.

Which shared challenges did they cite?

Casten listed several problems he said the U.S. and other nations face together:

• Climate refugees — people displaced by floods, droughts and storms
• Financial volatility caused by climate change
• The need to decarbonize economies, meaning to shift them away from fossil fuels — a task he called especially pressing given the Iran war

The takeaway: the delegation frames climate change as a shared global problem that persists regardless of Washington's official stance.

Does this change U.S. policy?

No. The lawmakers have no authority to negotiate for the United States, and the country remains outside the Paris agreement. Their role in Antalya is informal — meetings, side events and signaling rather than treaty talk.

Still, the trip matters as a signal. When a country exits a major international agreement, other governments watch to see whether domestic politics might reverse course. A bipartisan-adjacent congressional presence at COP31 tells partners and allies that climate diplomacy has not disappeared from American politics.

The visit also comes at a delicate moment. With the Iran war straining global energy markets, debates over decarbonization have grown more urgent and more contested at the same time.

What happens next depends on Washington, not Antalya. For now, 19 lawmakers plan to carry a simple message: the United States as a government is out, but many of its elected representatives are still in.