"Oh, it's totally a different set of questions" you get in Hollywood than the ones in Washington, he says, raking his fingers through that mess of floppy, boyish curliness. "One is, 'Who are you wearing?' And the other is, 'How are we going to save the planet?' "

Mark Ruffalo.

If ever there was incarnate evidence of the way women conflate nurturing and lust, it is Oscar-nominated Mark Ruffalo. The rumpledness. The feral way he ravaged Julianne Moore in "The Kids Are All Right." The sense that he is vaguely lost, not merely in the metaphorical sense but literally, as well - as today, when he suggests going "next door" for some food, then wanders outside before you can figure out which next door he means, and by the time you find him he is happily ordering a Greek salad and chili fries at Good Stuff Eatery, a locavore joint on Pennsylvania Avenue SE.

In short: He's cute as hell, but you know how this would play out - it's supposed to be one night of fun, and three years later he's still sitting on your couch and somehow you're paying for his dental insurance. But for now, we're just eating our salads.

Mark. You spent the morning meeting with congressmen on Capitol Hill. What issues were you discussing?


Hee hee hee hee hee.

"Hydraulic fracking." He's talking about the controversial and potentially polluting natural gas extraction process by which tons of water are infused with chemicals. "They blast the mixture underground at such high levels that it fractures the bedrock, which allows the natural gas to escape."


This is the new Ruffalo, the activist dad who several years ago abandoned the Manhattan/Hollywood celebribubble in favor of a farm in Upstate New York's Catskill Mountains. "I know all my neighbors. It's beautiful and healthy, and in the winter there are blankets of snow covering the rolling hills," he says. "But I'm raising three kids up there, primarily because it's supposed to be so clean, and all of a sudden I'm in the middle of a public health fight."

He first learned about the fracking debate at his local farmers market, where he goes to buy the things that he and his wife, Sunrise Coigney, don't grow in their own garden. (But they grow almost everything. They are those people. Asked to identify anything in his salad he could have harvested himself, he lists everything but the cheese.)

That initiation was two years ago. Since then, he's become the Natural Resource Defense Council's most recognizable face, lobbying the state government in Albany to ban the practice in New York, and now working at the national level. Tonight he'll meet up with documentarian Josh Fox for a special screening of Fox's fracking documentary, "Gasland." It has been nominated for an Oscar.

Right, this is the other thing that's going on in Ruffalo's life right now. Ten years after he hit big as Laura Linney's vaguely lost brother in "You Can Count on Me," he's been Academy Award short-listed for Best Supporting Actor for his performance as Moore's vaguely lost sperm donor in "The Kids Are All Right." The character, Paul, is a laid-back grower of organic foods; Ruffalo's naturalistic performance makes one wonder whether he actually realized he was in a movie.

Coigney had insisted he do the film, and "it's just as much her nomination as mine. An actor's wife is not an easy gig."

"I do feel like I have this new worth," Ruffalo continues. Not from himself - a guy who grew up in Wisconsin and Virginia Beach - but from the Hollywood institution that treats "Oscar nominee" as an official title, like a PhD at the end of your name.

"At the beginning of your name," Ruffalo says. Then he starts to giggle. A few days ago, he received a DVD in the mail. "Nominee etiquette," he says. It offered helpful instructions for how to behave at the show. "It starts with brush your teeth, comb your hair, it's a good idea to wear a tuxedo. Then they move on to no booing, no hissing, no yelling things out." Also, "it's very important that you don't talk about the weight of the statue. That's been done. Leave that one alone. And don't kiss the person giving you an award."

He finds the whole situation amusing, which might be the result of living away from it all. Or it might be the result of the perspective-altering brain tumor that he battled in 2002. He'd dreamed he had one, and when he went to the doctor to be on the safe side, the doctor found out Ruffalo was right.

Either way, Ruffalo's life right now seems to be more about his work offscreen than his work on it - though he is gearing up for his role as the new Incredible Hulk in "The Avengers." He can see the headlines, written by the same people who now title all of his profiles, "Ruffalo Is All Right." "How about: 'Ruffalo Goes Green: Activist, Actor, Hulk?' " he suggests.

The activist work? That's just beginning. "A real movement is starting to coalesce around water," he says. "Our idea is to go from city to city [and unite] whatever water groups are fighting mountaintop removal, or water scarcity, or gas drilling - anywhere that water is under attack, we host a concert there."

For now this idea exists only as a blue pin in the shape of a water droplet that he wears on his lapel. The concerts and the fracking legislation are only parts of what he sees as a larger, philosophical issue.

The ultimate goal, he says, is that "we need to start thinking about clean, publicly owned water as a constitutional right."

That's in the hazy future. First he must navigate the Oscars, which, "as an event, is fatally boring," he insists. "They don't let you get up and dance or anything."

And who will you be wearing?

"Neil Barrett."