Seventeen months after his Late Show finale, David Letterman returns to television to host an upcoming episode of National Geographic's climate change docuseries Years of Living Dangerously. Letterman's episode, which was announced in September 2015, features the former late-night host travels to India to examine how that nation provides energy to its entire population.
"I'm in no position to editorialize about solar power or any kind of renewable power," Letterman says in the promo (via Entertainment Weekly). "I've created, excuse the expression, kind of a love affair with this. Think about the coal-fired, dangerous, smoke-belching generating plants, and then you look at this and it's friendly. There's something very appealing about this, and it's smooth. Look at it: I can touch it and it's safe. I put my head right there on it."
A solar-powered current then repeatedly jolts letterman after he rests his head and retirement beard on the panel.
The second season of Years of Living Dangerously premieres on National Geographic on October 30th. Other hosts this season include Arnold Schwarzenegger, America Ferrera, Saturday Night Live's Cecily Strong and more.
In June, Letterman resurfaced for an interview with Tom Brokaw where he called Donald Trump "despicable" and "repugnant."