Having grown up in a family that recycles, Erica Messer makes sure the set of "Criminal Minds," the show she produces, does the same — among other green practices. "My granddad used to have me stomp on his Pepsi cans and we'd take them to the recycling place. I grew up doing it so if I see a can in the trash I take it out and put it in the recycling bin. We have bins and recycle everything on the stage, and all internal documents and scripts are double-sided. It reduces the costs but it's more than that. It makes me crazy" when people don't do it, said Messer, at CBS' fall launch event at the Paley Center for Media in Beverly Hills.

The procedural drama, which follows the elite BAU criminal profiling unit of the FBI as they hunt down serial killers, returns for its seventh season Sept. 21 on CBS. "I think the writers do a really good job of keeping the show very smart. It's a very dark show but I think the reason people like is not just that it's creepy and dark. It's a very smart, intuitive, informative show," Shemar Moore accounted for "Criminal Minds'" enduring popularity. "I think the seven of us have a really good chemistry. We don't step on each other's toes. Whoever you are you can relate to at least one of us," the actor (pictured below with Kirsten Vangsness), who recycles at home, added.

Paget Brewster, whose character Emily Prentiss' death turned out to be faked, is returning to the show along with A.J. Cook this season. "I'm very excited to be back. I love the action aspect," said Brewster, explaining that she has "to come back from the dead to handle a problem and have to present myself to the BAU. People have different reactions to the fact that I'm not dead and that they were lied to," said Brewster, acknowledging that it was "hard to get fired, but it was exciting to look at other stuff. I miss comedy." She shot a sitcom pilot that didn't make it, but otherwise made use of her time off by traveling to London for business and pleasure, New York for a wedding, and installing a koi pond in her yard next to the garden where she grows vegetables like peppers, tomatoes and fennel and herbs including basil, cumin and oregano. "I don't use any insecticides," she said, noting that she avidly recycles and "buys everything from eBay."

For Cook, being fired and re-hired was "a roller coaster, every emotion you could possibly think of." She hesitated to return at first, but fan support helped change her mind, and she's happy that she did. "There's some really great stuff coming up for J.J. this year. We're going to see her private life a little bit. We're going to see the baby daddy — Josh Stewart — and my son is being played by my real-life son. He already appeared in an episode so we figured why not? He's going to come to the set with me anyway. He loves coming to set," reported Cook, who as a mom is concerned about chemicals in the home. "I use green cleaning products," said the self-described "neat freak," "and we recycle — I'm Canadian and we grew up with it." She'll appear in the upcoming movie "Least Among Saints" in a role "that's a 180 from what I do on 'Criminal Minds.' I play a drug addict. It was really important to me to do something different."

While he's glad that the old team is back together, Thomas Gibson says the characters will deal with "fallout from what went down. There are trust issues that take a while to come back." As team leader Aaron Hotchner, "I've told certain members of the team to get over it, and we'll see if they do or not," said Gibson, who admires Hotch's integrity. "He's a pretty stand-up guy. He takes fidelity, bravery, integrity very seriously — maybe too seriously." An Austin, Texas, resident, he commutes to work in Los Angeles but tries to conserve in other ways, like recycling and driving a diesel-powered Audi. "I try to maintain consciousness about it at all times," he said.

Matthew Gray Gubler also drives a diesel auto, "a 1979 station wagon that gets better mileage than any Prius out there, about 36 miles to the gallon, and the battery will not destroy the environment," he said of the vintage vehicle, which has 140,000 miles on it. It was in pristine condition when he found it after hunting for years for it, the same model as the car his parents used to take him home from the hospital. He also recycles and grows his own fruits and vegetables, everything from chard and avocados to lemongrass, mangos and loquats. Playing the brilliant Dr. Spencer Reid on "Criminal Minds," he's often expected to be as smart off screen. "I'm not a genius in real life. But there are worse problems. I'd rather play a genius than a porn star," said Gubler, noting that new writers have brought "a little more intrigue and suspense" to the show this season. This Christmas, he'll be heard voicing Simon for the third time in "Alvin and the Chipmunks: Chip-Wrecked." "It's going to be the best 'Chipmunks' yet," he promises.Kirsten Vangsness, who plays computer wiz Penelope Garcia, will have the chance to get out from behind the screen more this season, and will be the main focus of the eighth episode. She recently enlisted co-stars including Moore and Joe Mantegna to join her in a film she's executive producing from a play she was in called "Kill Me, Deadly." "It's a film noir spoof, a detective story," described Vangsness, who also appears in the upcoming "Chicago 8," about the 1968 Democratic Convention riots, and online in "Pretty: the Series," which she appears in and produced. The sets of that project and "Deadly" were conservationist: "Everybody brought their water bottles," said Vangsness, who goes a step further on "Criminal Minds." "I bring my own trays, wash them, and use them again the next day. I also save extra napkins. I put them in my purse and use them later."

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'Criminal Minds' cast: Deadly serious about recycling
'Criminal Minds' actors — Erica Messer, Shemar Moore, Paget Brewster, AJ Cook, Thomas Gibson, Matthew Gray Gubler and Kirsten Vangsness — talk eco-awarenes