The phrase “climate change” was not used once in the three presidential debates.

Four years ago, both presidential candidates agreed that climate change was a critical issue demanding urgent attention. But that national call to action has disappeared and in the past four years public opinion on the climate issue has cooled.

What happened?

In Climate of Doubt, correspondent John Hockenberry discovers how climate skeptics mobilized, built their argument, and undermined public acceptance of a global scientific consensus.

So, who, exactly, are these influential skeptics, and what strategy has made the difference in shifting the momentum? What’s next in the climate wars? Is there an end in sight?

We asked the film’s producer Catherine Upin and correspondent John Hockenberry to join us to discuss these questions and take yours in a live chat on Thursday at 1:30 p.m. ET.

We’ll also be joined by guest questioner/resident expert Elizabeth Kolbert, a staff writer at The New Yorker. Here’s the first part of her award-winning series on climate change for the New Yorker, “The Climate of Man.” She’s also written an acclaimed book on the issue, Field Notes from a Catastrophe.

You can leave a question in the chat window below, and come by at 2 p.m. ET on Thursday, Oct. 25 to join the live discussion.