To the surprise of . . . well, practically nobody, NBC announced Monday that Uncle Howard will be back on “America’s Got Talent” next season.

Actually, Howard Stern broke the news on his Sirius radio show Monday morning.

“Here’s my reasons for going back,” Uncle Howard told his listeners.

“This is the only show that has this kind of clout for what I would say is ‘non-singers.’

“I just find it so refreshing that . . . people can get this type of exposure, who have a shot at stardom. I feel my work is unfinished there,” he said.

Howard Stern’s return to ”America’s Got Talent” means the show has a huge payroll. (STEPHEN CHERNIN/REUTERS)

Stern also said, “I felt I could not walk away” — which isn’t surprising, given that he joined the show last summer for a reported $20 million salary. The network announced with great fanfare that it had hired the shock jock to replace Piers Morgan on the show and even moved the production from Los Angeles to New York for Stern’s sake.

Nonetheless, “AGT” opened with about 4.5 million fewer viewers than it did the previous summer.

Similarly, Simon Cowell, who exec-produces both “AGT” and Fox’s singing competition, “The X Factor,” coughed up a reported $15 million to snag Britney Spears for the “X” judges panel in hopes of goosing that show’s disappointing ratings. With Britbrit added to the show, ratings are down about 20 percent year to year.

That does not bode well for the producers of Fox’s “American Idol,” who forked over $18 million for Mariah Carey in hopes her presence would boost that show’s sagging ratings.

“I’m ready to come back. . . and I’m going to be more straightforward and more direct than I was the first season,” Stern promised fans Monday morning.

Wait — didn’t he promise he would be totally straightforward and direct last season?

Lachey as NBC host

Speaking of the reported $15 million to $18 million being spent on celebrity judges for singing competition series, NBC announced Monday that it had hired Nick Lachey to host its new Practically Perfect Singing Show, titled “The Winner Is,” on which there are:

No judges.

“The Winner Is” hails from the creator and a producer of NBC’s “The Voice,” which itself is down noticeably this fall compared with its most recent spring edition — even when you take out the spring’s boffo post-Super Bowl episode.

If “The Winner Is” succeeds, it would save the network a bundle. Lachey, Jessica Simpson’s ex and once a member of the boy band 98 Degrees, can’t be that expensive; NBC noted that his most recent gig was hosting three seasons of its own, unsuccessful singing competition, “The Sing Off.”

On the new show, contestants are judged by studio-audience vote.

Sure, there’s some expense. Each week, two singers perform head to head. After each showdown, the studio audience votes for the best performer. The singer who loses is booted. But before the winner is announced, the players are offered a cash amount to walk from the competition. The dollar amount goes up with every round.

In the finale, eight singers will duel and negotiate. When, finally, just two singers remain, they’re each offered $100,000 to walk. If neither does, the studio-audience voting determines who gets the $1 million prize.

Even so, comparatively, “The Winner Is” is dirt cheap.

Big climate-change docu

Showtime has ordered a documentary series for next year on the impact of climate change on humans — to be exec-produced by two enormous Hollywood egos, two “60 Minutes” producers, one ex-California governor and a partridge in a pear tree.

“Years of Living Dangerously” is literally polluted with exec producers, including James Cameron and Jerry Weintraub, former governer Arnold Schwarzenegger, “60 Minutes” producers Joel Bach and David Gelber and climate expert Daniel Abbasi.

“60 Minutes” is a CBS newsmag — CBS being the owner of Showtime.

Matt Damon, Don Cheadle and Alec Baldwin are set to narrate “Years of Living Dangerously,” and Ed Norton may jump on board, too, Showtime said in Monday’s announcement.

Reporting for the project: New York Times journalists Thomas Friedman, Nicholas Kristof and Mark Bittman, as well as MSNBC host and political commentator Chris Hayes.

Abbasi is founder of GameChange Capital, a venture capital firm that funds low-carbon solutions to reduce greenhouse gas emissions.

“We’ll make it exciting. We’ll make it investigative. We’ll bring people the truth. . . . People are always hungry for the truth,” Cameron swash-buckled in Monday’s announcement. Cameron’s sci-fi flick “Avatar” included themes of the havoc wrought by civilization on the planet, Showtime reminded us.

“The recent devastation on the East Coast is a tragic reminder of the direct link between our daily lives and climate change,” David Nevins, Showtime’s entertainment president, said more cautiously.

Schwarzenegger had no statement, but, as Governator, he’s the guy who takes credit for enacting the nation’s largest greenhouse-gas emissions trading program. He recently announced plans to establish the USC Schwarzenegger Institute for State and Global Policy, devoted to seeking bipartisan solutions to environmental, economic and other public policy issues — with him on the think tank board and holding a public policy professorship at the school.

To read previous columns by Lisa de Moraes, go to tvblog.