The end is Nye

"Bill Nye's Global Meltdown" allows the famed science guy to experiment with his hammy side by taking on the guise of a patient suffering from "climate change grief." His counselor? Arnold Schwarzenegger. His analysis: "Hey, Bill. It's not a tumor!" 7 p.m. Sunday, National Geographic Channel

Read my lips

In "Jeff Dunham: Unhinged in Hollywood," the popular comedian boldly goes where few ventriloquists have gone before, although he'd better not accidentally call his guest, UFC champ Chuck Liddell, "dummy." Brad Paisley performs — while drinking a glass of water! 7 p.m. Sunday, Comedy Central

Killer twist

And then there were four? Most signs from last week's episode of "The Walking Dead" point to the demise of one of the five remaining main characters from the first season. But it's not entirely clear if it really was the end for NAME REMOVED BY SPOILER-ALERT POLICE. We may not get the answers right away — previews suggest we may get a flashback episode. 8 p.m. Sunday, AMC

Neal Justin