In a conversation with Google chief executive Eric Schmidt, film director James Cameron urged technology-minded people to become better stewards of the planet. That was a fundamental message of Cameron’s blockbuster film Avatar, and it’s also the advice he has for people who have their heads down building cool technology in Silicon Valley.

The two men spoke on stage at the Churchill Club dinner Wednesday night in San Jose, Calif.

Schmidt is a model for the kind of person Cameron was talking about. Schmidt admitted that he wasn’t as aware of environmental issues until he came to Google and found that founders Larry Page and Sergei Brin were highly sensitive to the issues. Schmidt became a convert after he commissioned a study and found that “being green means good business” and would ultimately save Google lots of money. Too often, Schmidt said, technologists make the mistake of ignoring the environment in pursuit of innovation. In 2006, Schmidt and his wife Wendy set up a foundation dedicated to issues of sustainability and responsible use of natural resources.

Cameron said that humans have to evolve into “techno indigenous people, not of the state, not of the nation, but of the planet.”

“That hasn’t been done before and I don’t know how we do it,” he said. “Maybe it’s one of the tipping point things in a good way. You notice now that solar energy is slowly starting to accelerate. I have to think that people of good conscience have to prevail. Education is important. We have to challenge our leaders to be leaders, getting the public to buy into it. Right now, they are in denial mode because of the economy. That is natural. People have to pay their mortgages.”

Cameron and Schmidt said one step is to vote down Proposition 23, an initiative on California’s ballot for the election next week. The proposition aims to roll back strict environmental standards imposed by California’s AB32 law, or the Global Warming Solutions Act of 2006. Cameron said that the “hard-fought” environmental law should become a model for the nation in fighting global warming. Schmidt said that the jobs gained by clean energy would offset any jobs lost in the coming years.

Those are people who use their great knowledge and technological innovations to take care of the planet. He fears that global warming will wipe out 70 percent of the species on the planet in the current century. A simple two-degree increase in temperature would likely kill off the coral reefs of the world, he said.

While he tried to make a great film with Avatar, he also used it as a vehicle for his environmental message. People have to realize that everything is connected, he said. The people in Minnesota might actually like it if the temperature of the planet rises five degrees. But they won’t like it if they have to send their children to fight wars that arise because the temperature rise elsewhere causes droughts, mass migrations, dislocations and conflict.

Schmidt said that Cameron’s genius wasn’t reflected in his passion for filmmaking, technology, or environmentalism. Rather, he said that the genius of Cameron was in his deep knowledge of all three fields.

Cameron said that his own passion for environmentalism would be evident in the scripts of the upcoming Avatar sequels that were announced today.

“This is probably the toughest problem the human race has ever faced,” Cameron said of global warming.