Hollywood celebrities have long prided themselves as the social conscience of America. Now, it seems, they’ve widened their reach to the entire Earth.

“Climate change is real, it is happening right now,” Leonardo DiCaprio said in his Oscar acceptance speech in February. “Let us not take this planet for granted.”

With those words, DiCaprio did more for climate change advocacy than any other individual effort, ever, according to a new study. Compared to the Paris climate summit last December—in which world leaders agreed to the first-ever global accord designed to curb greenhouse gas emissions—DiCaprio’s speech was four times as effective when it comes to increasing public interest in climate change.

Still, as powerful as it was, DiCaprio’s speech was only viewed by tens of millions of people. On Friday, an estimated 3 billion people watched the opening ceremony of the Olympics in Rio de Janeiro, which included a stark, yet hopeful message about climate change. Brazilian filmmaker Fernando Meirelles directed the opening ceremony, which was probably the single most-watched moment yet about the single most important issue our planet is facing.

Americans watching the climate change segment of #Rio2016 ceremony are reminded that in most of the world this is not controversial. — Bill McKibben (@billmckibben) August 6, 2016

Moments like these are becoming more common as it becomes painfully clear that the world is running out of time to prevent essentially permanent and potentially catastrophic effects of global warming. Scientists have struggled for decades to get the same basic message across: The world is warming, humans are the cause, and we know how to stop it. It seems, given how resoundly Leo’s message was heard, that Hollywood has the potential to become the single most consequential voice amplifying scientists’ calls to rapidly change course away from fossil fuels. That signal boost can’t happen soon enough.

It doesn’t really matter that Leo flies like a king and has a personal carbon footprint that vastly tops anything we mere mortals could ever dream of, or that Brazil’s own record of protecting its country’s unique environment is mixed at best. What matters now, in this 11th hour, is awareness and hope. We need to increase the number of people clamoring for action. And that’s what Leo can help do.

“All that I have seen and learned on my journey has absolutely terrified me,” said DiCaprio in an address to world leaders at the United Nations in April. “A massive change is required right now. … You are the last, best hope of Earth.”

Hope wasn’t always the focus. Ten years ago, possibly the only Powerpoint-based Oscar-winning film in history debuted. An Inconvenient Truth was a lightning rod, inflaming the debate on climate change and setting Al Gore apart as a leading political voice on communicating climate science. It was the start of the most important shift in global climate politics so far, and defined a decade of environmental messaging: Scare the bejeezus out of your audience via charts and graphs.

To some extent, that tactic has worked. For the first time, we have hard evidence that voters really, deeply care about climate change. Unfortunately, we’ve also seen the issue become one of the most polarizing in American politics. Whether you believe in climate change or not has become wrapped up in your political identity. That’s why the infiltration of climate science and awareness into mainstream culture is so heartening—if climate change becomes part of the narrative that surrounds everyday life, perhaps it will become less polarized.

Today, we’ve got much more beautiful people interested in the issue (no offense, Al) and the stories being told, taken from both the real world and those of our imaginations, are much more persuasive. The Emmy Award-winning series “Years of Living Dangerously,” which recently got renewed for a second season, features celebrities like Harrison Ford, Don Cheadle, and Matt Damon traveling the world and engaging with climate-related issues in often confrontational and eye-opening ways. (Indonesia threatened to deport Ford after he confronted the country’s forestry minister.) Climate change—or broadly dystopian environmental themes, at least—are appearing with growing frequency in movies and television. Game of Thrones, Interstellar, the Hunger Games, and the Revenant—the film for which DiCaprio won his Oscar all essentially tell the same story: If we blindly continue on our current path, things could get really, really bad.

But for climate change to become a top issue among the American public, we’ll need environmental themes to infiltrate popular culture even more. Hollywood has done a great job scaring us, but it now needs to move forward to solutions. In some ways, that’s a harder story to tell. Earlier this year, Charles Ferguson’s attempt at hope in his new climate change documentary A Time to Choose felt more like a long ad for the renewable energy industry. Perhaps a movie that is free to move beyond reality would be more inspiring—though that speaks to the sad state we are in.

Real change will happen only when our society’s concern for the environment reaches a critical mass and—this is important—demands a better world. Hollywood has gotten pretty good at showing us what might happen if we don’t act soon. The next step will be to imagine what a better world looks like.