(Reuters) - As temperatures continue to rise and habitats come under threat, a group of Hollywood heavyweights is seeking to bring the spotlight back on climate change with a new documentary.

"Years of Living Dangerously," a nine-part documentary beginning Sunday on CBS Corp's premium cable network Showtime, chronicles the human impact on the global climate and the consequences for humans of climate change.

From the disappearing forests of Indonesia to the increasing frequency of California's wildfires and the crippling Texas drought, the documentary wants to put the focus back on an issue that has lost visibility since the days of the 2006 Oscar-winning documentary "An Inconvenient Truth."

"This is such a critical time," said James Cameron, best known as director of blockbuster films "Titanic" and "Avatar" and an executive producer on "Years of Living Dangerously."

"The devastation to the planet that we'll be experiencing in the next century is really, I think, pretty unfathomable for most people, and I think that what the series can do is to bring it home and make it real, make it real in people terms."

To do that, Cameron appealed to well-known Hollywood actors to act as correspondents, including Harrison Ford, Matt Damon, Don Cheadle, Jessica Alba, Michael C. Hall and Arnold Schwarzenegger, also an executive producer on the documentary.

In the first episode, "Praying for Rain," Cheadle travels to Plainview, Texas, where residents face economic hardship due to the severe drought in the region that forced the closure last year of the meat-packing plant owned by Cargill Inc, the town's chief employer.

Cheadle meets a former employee who has fallen on hard times since Cargill's closure and believes the drought is "biblical."

But Cheadle also finds the scientist Katharine Hayhoe, an evangelical Christian and professor at Texas Tech University, who has made it her mission to explain to people the science behind the drought - notably that warmer temperatures are making droughts more severe, affecting jobs, food and health.

A combination of legislative gridlock in the United States and economic malaise in the wake of the 2008 recession have pushed climate change policies, aimed at stemming greenhouse gas production, onto the back burner.

The latest report from the U.N. Intergovernmental Panel on Climate Change (IPCC) in March said the effects of warming are being felt everywhere, fuelling potential food shortages, natural disasters and raising the risk of wars.

Cameron believes that progress can only come from legislative change.

"I think the U.S. is trailing the pack. I think the U.S., instead of showing the kind of moral leadership that it should, is being shamed by almost every other country in the world that's actually taking action," the director said.

"If we're going to have change in this country, it's got to come from the grassroots up. It's got to be the average citizen realizing that their lives and well-being are in jeopardy."

FAME FOSTERS ACCESS

Bringing Hollywood voices to the issue has its advantages, as Ford shows in the first two episodes of "Years of Living Dangerously." The "Indiana Jones" actor traveled to Indonesia to see the impact of deforestation, and demanded answers from both the forestry minister and Indonesian president in meetings that attracted international coverage.

"If people are watching people whom they associate with escapist fiction, laying bare some sobering facts, it may lend a resonance they wouldn't otherwise have," said Hall, who traveled to Bangladesh, a nation threatened by the rising sea levels.

As one of Hollywood's most successful directors, the 59-year-old Cameron and has used his medium to get people thinking about the impact of climate change. His 2009 sci-fi 3D epic "Avatar," about an alien species who come under threat when humans mine precious minerals from their planet, was a prime example.

With "Avatar" sequels planned in 2016 and 2017, Cameron said the films will be "about our connection to nature and our connection to each other."

Joining the documentary's celebrities are the scientists, a group of nine advisors who aid the stars in making the scientific case about climate change.

But the documentary also acknowledges the climate change skeptics, from the Texans who believe droughts are brought on by the hand of God, to the scientists who believe global warming is part of the planet's natural process.

Even the experts can be skeptical. An author for the U.N.'s IPCC report in March pulled out of the writing team saying the report was "alarmist" about the threat of climate change.

But Cameron makes clear he is skeptical of the skeptics.

"I think it's important to analyze each of the skeptics' arguments very carefully and when you analyze them, they fall apart; they fall apart in the light of science."