Former Late Show host David Letterman will briefly return to television to discuss climate change.

Letterman will appear in the upcoming season of National Geographic’s Emmy Award-winning climate change series Years of Living Dangerously when the sow returns to TV next fall, according to The Hollywood Reporter.

“From the damage wrought by Hurricane Sandy to the upheaval caused by drought in the Middle East, this groundbreaking documentary event series provides first-hand reports on those affected by, and seeking solutions to, climate change,” a description of the show reads on IMDB.

Nat Geo CEO Courteney Monroe told THR Letterman’s involvement with the project “speaks to how passionate so many people are — like himself — about this issue and how important it is to our planet and to humankind, and I think it’s terrific that he’s attaching himself to it.”

Variety reports 68-year-old Letterman will travel to India for one episode of the docu-series, and his episode will focus on the country’s efforts to increase its use of solar energy over the next decade.

Jack Black, Ty Burrell, James Cameron, Thomas Friedman, Joshua Jackson , Aasif Mandvi, Olivia Munn, Arnold Schwarzenegger, Ian Somerhalder, and Cecily Strong will all join Letterman for the second season.

Courtney Monroe said of Letterman and other stars attached to the series, “What’s interesting and important is this is not a political issue at all, but it’s an incredibly important issue that affects all of us as people living on this planet, and I think that’s why they’re able to attract the names that they’ve attracted.”

Actor Harrison Ford appeared in two episodes of the season one.

Years of Living Dangerously Producers David Gelber and Joel Bach told Variety they became interested in getting Letterman involved with the show because he always expressed interest in the topic of climate change while he was hosting The Late Show.

“You could just tell. Whenever they would have a climate discussion, he would really kind of perk up,” Bach told the industry site. “He’s definitely invested in this issue.”

Letterman has been inactive since leaving The Late Show in May after 22 years at the helm.