William Brangham:

The timing is lost on no one. The president notified the rest of the world again yesterday that, one year from now, the day after the 2020 elections, the U.S. will formally withdraw from the Paris climate agreement. That's the voluntary global accord signed in 2015 by nearly 200 nations to cut greenhouse gases to slow the warming of our planet.

The U.S. is the second largest carbon emitter in the world, behind China. In fact, it was American diplomacy negotiated during President Obama's tenure that was crucial to getting China and India to reduce their emissions.

But President Trump, who has mocked the idea of climate change, has long maintained the agreement was a bad one, one that would stunt America's economic growth.

So let's look at the consequences of this decision.

Todd Stern was the chief climate negotiator for President Obama. He's now a senior fellow with the World Resources Institute and the Brookings Institution.

Welcome back to the "NewsHour."