When director James Cameron trekked to Washington in 2010 to press for action on climate change and appear at an Earth Day rally, he returned not just disappointed, but disillusioned.

One lawmaker, worried about the shift toward denying the existence of man-made global warming, advised him that to even use the word “climate change” was the “instant kiss of death for any proposed legislation.”

Five years later, Cameron hasn’t given up, and he’s even a bit more optimistic. On Tuesday, he will take part in the U.S.-China Climate Leaders Summit in Los Angeles, appearing at a lunchtime panel with Sam Kass, former White House senior nutrition policy adviser, about the relationship between food and climate change. This week, Cameron and Los Angeles Mayor Eric Garcetti taped a series of social media video segments to promote the summit.

“This time around, [climate change] is definitely on the agenda,” Cameron says. “And that is not coming from our so-called leaders. That is bubbling up from below, from concerned citizens saying, ‘This needs to be discussed. You guys need to talk about this.'”

Cameron is pursuing more of a niche focus when it comes to climate change activism, citing “the real lack of information at the public level about the links between sustainable agriculture and food choices we are making and climate change, and there is a direct impact.”

“One of the things that has given me hope is that there are other answers besides the obvious ones,” he said. “The obvious ones are that we’ve got to wrangle transportation to a certain extent so that we can cut down on gasoline, and we’ve got to control fossil fuels. But when 14.5% of greenhouse gas emissions are coming from animal agriculture, that is a big thermostat that you can turn down. The average person can start to make a big difference right away.”

Cameron founded the Avatar Alliance Foundation, named for his highest-grossing movie of all time, to pursue climate change issues, and the organization has distributed grants for such things as ocean science research. More recently, he founded the Food Choice Task Force, jointly funded with cellular mogul Craig McCaw and others, with a recent initiative called My Plate, My Planet.

Among other things, the initiative has gathered dozens of groups and scientists to push federal officials to adopt dietary guidelines higher in plant-based foods, running open letters in March in The New York Times, the Washington Post and Politico. The Dietary Guidelines Committee, which makes recommendations to the U.S. Department of Agriculture and the Department of Health and Human Services, recommended such an approach, with implications for the school lunch program and, when it comes to education, the food pyramid.

The effort has run into opposition from the meat industry, which even started a petition campaign called Hands Off My Hot Dog, charging that the guidelines committee overstepped their bounds “by not focusing on nutrition and instead wandering into environmental issues.” They cast the issue not only as personal freedom, but make positive health claims about animal-based diets. The committee advised reducing consumption of red and processed meat, although they didn’t recommend doing away with lean meat.

Cameron is unabashed in linking a healthy diet to the environment, but he also acknowledges the pushback. “All it takes is someone, somewhere, no matter how ridiculous their argument is, saying, ‘This isn’t really a problem,’ and people will latch on to that because they would rather hear that.”

Almost four years ago, Cameron and his wife Suzy Amis Cameron changed their diet away from animal products, and while he calls it a “win-win” for personal health and the environment, convincing the public to change eating habits is something that has vexed health advocates for generations.

He said that when it comes to messaging to the public, he’s learned a bit from his experience making the 2014 Showtime documentary miniseries “The Years of Living Dangerously,” which won an Emmy but didn’t do well in terms of viewers. Nevertheless, he says that a second season is in the works.

“You can’t just go running down the street telling everyone, ‘The sky is falling.’ You have got to have an action plan, and this struck me as a place where people could quickly make a difference, and they just needed the information,” he says.

The Food Choice Task Force, he said, did research to confirm the 14.5% number, which is from the United Nations Food Agriculture Organization. He said that the figure is “a highly conservative and defensible number,” but still significant because it is larger than that from transportation emissions.

Yet information alone won’t change hearts and minds. The topic of animal agriculture’s contribution to climate change often has been one of ridicule — for example, the methane that comes from cattle. As Cameron noted, what little people have heard “has been laughed off as, ‘Oh, cow farts. I’m supposed to be afraid of that?’ Well, it turns out there’s 1.5 billion cattle in the world, and all they do is stand around a digest grass and produce methane.” (He also notes that “the joke is on them because most of it is actually burped up.”)

The director rattles off stats about the long-term prospects of population growth by 205o, to about 9 billion to 10 billion people. Some 38% of the earth surface has been cleared for agriculture, and animal agriculture occupies 29% of the ice free land.

“We have to come up somehow with 70% more food production, out of a planet where most or all of the land has already been acquired for agriculture. How are you going to do that? It is actually not technically possible, unless you start eating the plants instead of feeding the plants to an animal, which makes it 10 times less efficient. So we just have to do it.”

Still, Cameron said that what is required is to reach “people on an emotional level.”

“You can’t just barrage them with facts, because people can counter facts with other facts. Most people don’t think with facts, they think emotionally, in terms of their social and political in-group. So I think you reach them emotionally when you say, ‘Listen, we are talking about our kids. We are talking about our future.’ It can’t just be doom and gloom. You have got to give them steps.”

That will be part of what he talks with Kass about at the summit, where, in addition to talking about diet, Garcetti and other city leaders from the U.S. and China will commit to emissions goals. The agenda also includes a speech from Vice President Joseph Biden and a dinner at Warner Bros.

Garcetti, too, sees a shift in public attitude toward climate change, what he calls “the interconnectivity of things,” relating all sorts of personal consumption habits to each other. He hopes that it will be a “consciousness-raising event as well as a commitment to specific actions.”

“The emissions that are in China actually blow all the way across the Pacific and a good number of particles that are here in Los Angeles come from that,” Garcetti said. “So we have a stake in helping China reduce that pollution. Plus we have got a great story here from a city that used to be smoggy that still is maybe the car capital of the world, but now is less smoggy, moving away from that car capital mentality.”

At Manhattan Beach Studios, where Cameron is based, production of the “Avatar” sequels will be “net energy zero,” with a one-megawatt solar-powered energy system placed on the roofs of soundstages.

He suggested that the subtext of the movie “Avatar,” the environment and sustainability, will carry forward in the sequels, although he is otherwise tight-lipped about details and release plans.

Cameron does plan on taking his mission for a sustainable diet to the production — within reason.

“They are my employees. They are not a cult, so I can’t tell them what to eat,” he said, but when his production team is fully in place he does plan to “get in front of them and make strong recommendations.”

He said, “Most people aren’t aware of this information, and when they become aware, some become ‘evangelist’ about it, or are willing to make big changes to their diet, for their own health and the health of the planet.”

Update: Here’s the interview with Cameron from Variety’s “PopPolitics” on SiriusXM.


Here’s Cameron and Los Angeles Mayor Eric Garcetti, talking about the U.S. China Climate Leaders Conference in Los Angeles: