On April 14 and 15, coinciding with the 100th anniversary of its sinking, ABC will present Julian Fellowes' ("Downton Abbey") new four-hour version of the Titanic story, starring a cast of British actors including two familiar to American audiences from their TV roles, Linus Roache from "Law & Order" and "Law & Order: SVU" and Sophie Winkleman, who plays Ashton Kutcher's girlfriend Zoey on "Two and a Half Men." In separate interviews, the actors discussed the production and what they're doing to be more environmentally conscious.

"I recycle. I drive a hybrid. I try not to waste paper and do things electronically when I can. My efforts have probably been more focused on humanitarian issues than environmental ones but my monthly donation to Greenpeace has been going on for 20-odd years," says Roache, a vegetarian-turned-vegan who originally gave up eating animal products for health reasons but has come to believe that a plant-based diet is best for human and the planet's wellbeing. "I think it's part of our evolution. I think consciousness has been raised around this issue," he says, noting documentaries like "Forks Over Knives." "My dad has just become vegetarian, and he's 80."

For Roache, attracted by the subject, Fellowes' involvement and narrative approach, the cast, the British production, and the chance to play an aristocrat, signing on to play the fictional Hugh, Earl of Manton was "a no brainer." Although he's played royalty in Shakespeare plays, he'd never played a high born man of this period, and felt able to connect to him because of his sense of humor and progressive attitude. He recalls being fascinated by the Titanic story as a boy, later devouring Clive Cussler's novel "Raise the Titanic" and last year, visiting the Titanic exhibition at London's O2 Arena. His preparatory research was more "about the period, the time, the class, the etiquette, the manners, the sensibilities, the political aspects of that time," and discussing with his fellow actors "what it could be like to live with that kind of entitlement."

He wasn't prepared, however for the physicality of the role. With its emphasis on character-driven human drama, not special effects, he wasn't expecting "Titanic" to be so challenging. "My memory of the whole shoot is mostly running around in a big, heavy winter coat in the middle of summer in Budapest under hot lights, pretending to be cold, trying to grab a lifeboat and picking up kids, doing all kinds of physical things. I think there were seven lifeboat sequences and they had to be repeated over and over again. We spent like three days on each one."

Roache has several theories on why the Titanic story still resonates. "The human hubris of the whole event, that this magnificent piece of engineering and the height of luxury set sail with some of the wealthiest people in the world, it was unthinkable that this could happen, and then Nature gets us. It pricks our pride and humanity. And I find it fascinating that there isn't one thing to blame it on, but a whole sequence of things," from missed ice warnings to missing binoculars to the fact that the iceberg ripped into five instead of four watertight compartments. We all think, 'Who would I have been?' 'Would I have lived or died?' 'How would I have behaved?' You never know until you're actually in the situation. That's what's fascinating about disasters and war and these heightened crisis situations where you find out what a human being is made of."

While he enjoys the versatility and variety of moving between different genres and period and contemporary roles, Roache prefers the latter "if you forced me to choose." His stint on "SVU" is over, but he recently did a pilot for ABC in which he plays a "very ambitious" U.S. Senator. "It's a supernatural thriller set in New York, the ultimate battle between good and evil."

Winkleman, in addition to recycling, composting for her garden, and "recycling absolutely everything," is conscientious about turning off lights, unplugging electronics, and drinking filtered tap water. She thinks bottled water is "completely insane," and she doesn't drive, as challenging as that is in Los Angeles, where she has been living for two and a half years. Not only was she homesick for London and her family at first, she missed walking and taking public transportation. Since the latter isn't practical in L.A., she gets rides from friends, her husband, and "Two and a Half Men" cast mates to and from work, but she's planning to learn to drive over the summer. "I thought very foolishly that I could make LA work for me as a non-driver and I just can't," she admits.

Winkleman was drawn to the historical tragedy's subject and Fellowes' script, and her character, a real Titanic passenger named Dorothy Gibson. "She was a movie star which is very unusual for the time. She was a musical actress, a model, a singer. She was funny, glamorous, quite a pioneer," she says, noting that although all of Gibson's films were destroyed except for one locked away in a vault, but she was able to hear an audio clip of her voice, "which was very helpful."

Making the miniseries, she was struck by the dichotomy between "the immense excitement at the beginning of the journey that contrasts so horrifically with the tragedy that would ensue," and found that the commotion, mayhem and terror that the film depicts really hit home. "There's something in the psyche about drowning and being trapped that's so horrifying. You're completely powerless," reflects Winkleman. Having not played a period part in a while, she enjoyed the challenge of portraying a woman from a more formal, mannered, romantic time before cell phones and casual behavior, as well as speaking with an American accent.

She gets to use her native King's English as Zoey on "Two and a Half Men," a job she raves about in all aspects, from the cast to the writing to the character. "She can be as funny as the guys and that's rare on a male dominated sitcom. She's funny and powerful and strong and she's got a life. She's not the cute bimbo waiting to be picked up by one of the guys. She's a mother. She's got a career. She doesn't put up with anything. It's a joy of a part." Her relationship takes a more serious turn when Zoey and her daughter move in with Walden in the April 16 episode. She reports that the set is quite eco-friendly: "they have water coolers and recycle everything."

While waiting to hear whether or not Kutcher will commit to another season of the show, Winkleman is doing a play starting April 26 at the Orpheum Theatre in L.A., a musical comedy called "What About Dick?" written by Eric Idle and starring Russell Brand, Jane Leeves, Eddie Izzard and Tracey Ullman, a royal assemblage of British comedians. But Winkleman, has an actual royal pedigree, albeit by marriage. Her husband is Lord Frederick Winsor, son of Prince and Princess Michael of Kent and 31st in line to the British throne.

They met in London in January 2007, "when we were leaving two separate parties and went for the same taxi. We shared the taxi to the same area of London, and we've been inseparable ever since." If that sounds like a cute romantic comedy scene, so does the proposal: he asked her to marry him by spelling out the words on a Scrabble board.

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'Titanic' stars reduce carbon footprints
Linus Roache and Sophie Winkleman discuss ABC's 'Titanic' miniseries, green living.