Carbon dioxide generated by 7 billion human beings is being absorbed by the oceans, making them acidic, killing off corral reefs and altering ocean ecosystems. That adds to the harm from fossil-fuel burning, pollution and industrial-scale overfishing.

“We’re essentially waging war on the ocean,” Earle said. It matters, she said, because, “No ocean, no life. No ocean, no us.”

The good news, she told an audience at Montana State University, is that today we have the tools to know something is seriously wrong.

More people, especially young people, care about making change. And thanks to powerful media, like photography and filmmaking, the message can be communicated to a wide audience.

Earle, a National Geographic “explorer-in-residence,” has been named a Living Legend by the Library of Congress and the first “Hero of the Planet” by Time Magazine.

On Thursday, she was honored with MSU’s award for achievement in science and natural history filmmaking education, during the 68th annual University Film & Video Association conference.

The award is named for Ronald Tobias, who founded MSU’s master’s program in science and natural history filmmaking in 2001 with a Discovery Channel grant.

Tobias called Earle a combination of Jacques Cousteau, Ralph Nader, Carl Sagan and Cesar Chavez.

Earle said she has heard people living in the Midwest say they’re so far from the ocean, it doesn’t affect them. They’re wrong.

“People far inland don’t realize that with every breath they take … with every drop they drink, they’re connected with the ocean,” she said.

It wasn’t until 1986 that scientists discovered one of the most important connections — a microscopic ocean organism, prochlorococcus, that produces 20 percent of the oxygen in the atmosphere, Earle said.

“One in every five breaths you take, you can thank prochlorococcus.”

This month Earle is coming out with a National Geographic book, “Blue Hope,” and a film on Netflix, “Mission Blue,” to explain the oceans’ peril and use “amazing photos” to share what she’s learned about the colorful creatures living in the deep.

Hope is in young people, Earle said, like Hong Kong’s 1,000 teenagers who pledged not to eat shark-fin soup. Millions of sharks have been killed for shark-fin soup, and blue-fin tuna have been severely overfished, she said.

Earle, who grew up in New Jersey, started scuba diving and exploring the oceans in the 1950s, and has spent weeks at a time living undersea for scientific research.

She was appointed chief scientist for NOAA, the National Oceanographic and Atmospheric Administration, under the first President George Bush, but resigned because her views on fisheries conflicted with the administration’s.

It was hard as a scientist to speak to the popular press, she said, crossing a line many academics are loath to cross. But she decided she had an obligation to speak out publicly, tell the truth and inspire people to change, so the Earth doesn’t become like Mars, which once had an ocean.

“We still have time,” Earle said. “Now is the time.”

Some 400 film school professors and professionals from across the nation are attending this week’s conference, said Dennis Aig, director of MSU’s School of Film and Photography.

“This is an organization teaching the filmmakers of the future,” Aig said.

Gail Schontzler can be reached at gails@dailychronicle.com or 582-2633.