Every year, the world’s elite gather like the Illuminati in the Swiss chalet town of Davos for the World Economic Forum, where they discuss how to solve humanity’s most pressing problems. Often that results in comically out-of-touch conversations, such as the idea, put forth at this year’s summit, that digital “upskilling” can solve economic inequality. But sometimes it provides a platform for someone like the 16-year-old Swedish climate activist Greta Thunberg, who appeared before these elites like the prophet Cassandra.

“Either we prevent 1.5 degrees Celsius of warming or we don’t,” she said at the summit in January. “Either we avoid setting off that irreversible chain reaction beyond human control or we don’t. Either we choose to go on as a civilization or we don’t. That is as black or white as it gets. There are no gray areas when it comes to survival.”

Thunberg’s bluntness is warranted: The Intergovernmental Panel on Climate Change warned last October that humanity has roughly twelve years left to prevent a rise in world temperatures that would make civilization unsustainable in its current form by the century’s end. Virtually all of the Davos attendees will be dead by the time that happens. Thunberg and the rest of her generation are now desperately trying to get them and other world leaders to act before climate change becomes irreversible.

Widespread student protests are largely unheard of in the United States, but there are notable exceptions. The marches and sit-ins against the Vietnam War in the 1960s and 1970s come to mind, as do last year’s walkouts against gun violence. In each case, young people were angry about a mortal threat to their lives: dying in a futile overseas conflict, or being murdered in one’s classroom by a heavily armed gunman. This year, another student movement is taking shape, this time to stop an existential threat to humanity itself. In February, thousands of students walked out of schools across Europe to call for stronger international action. Another student strike is planned for Friday in the United States and more than 70 other countries.

The anti-war left ultimately succeeded in pressuring Washington to abandon the conflict in Vietnam, but it took around a decade for small campus protests to grow into a mass movement, and their tactics sparked a conservative backlash that helped elect (and reelect) a Republican president. Millennials hoping to force leaders to act on climate change can learn something from their success—and even more from their failures.

The ruling gerontocracy won’t make it easy for younger Americans to translate their political energy into policy. HuffPost’s Michael Hobbs argued earlier this month that age may be the defining split in our democracy. Older Americans, he noted, are more likely to vote in elections and three times as likely to donate to political campaigns. They also tend to live in smaller rural states, giving them disproportionate influence in the Electoral College and the Senate. “Without a dramatic increase in immigration or a sudden doubling of the birth rate, this is likely to be a permanent shift,” Hobbs wrote.

These forces helped elevate Donald Trump to the presidency in 2016. His campaign was built around a weaponized nostalgia of sorts—the “again” in “Make America Great Again”—that appealed to older white voters who resisted cultural changes that shaped the Obama era. He also broke with GOP orthodoxy on the campaign trail by refusing to cut Medicare, Medicaid, or Social Security. His strategy worked. According to exit polls, the majority of Americans over 40 sided with Trump, including 62 percent of white Americans between 40 and 64 years old and 58 percent of those older than 65.

Trump loves to appropriate old political slogans. “Let’s make America great again” was Reagan’s theme during the 1980 election. “America first” was the rallying cry of isolationists before World War II. Most apt of all was his occasional reference to his base as the “silent majority,” a phrase first popularized by Richard Nixon in 1969. Nixon used it to describe what he saw as a clear division in those turbulent years. It implied that civil rights and anti-war activists—and the urban intellectuals who favored them—were a noisy minority, and that most Americans were working-class people who opposed social change.

Nixon’s theory was somewhat vindicated after he won re-election in 1972 in a 49-state landslide (though of course an electoral majority is far from an actual majority of the population). While Trump appeals to a similar demographic, they are neither silent nor a majority, electoral or otherwise. He lost the popular vote in 2016 by roughly three million votes and only won thanks to the flawed Electoral College. A similar bias toward smaller states kept the Senate in Republican hands. Thanks to a decade of partisan gerrymandering, Democrats had to win a wave election in the 2018 midterms just to secure a workable majority in the House of Representatives.

Trump regularly denies that climate change is real, once tweeting that it was “created by and for the Chinese” to make America less economically competitive. Since taking office, he’s withdrawn the United States from the Paris climate agreement, championed the U.S. coal mining industry over renewable energy, and placed dogmatic deregulators in charge of the Environmental Protection Agency. Trump once reportedly told aides that he wasn’t worried about the national debt because “I won’t be here.” That attitude also sums up his, and most Republicans’, approach to climate change.

But their nonchalance is at odds with public opinion on the issue. A Yale/George Mason University poll in February found that fewer than 60 percent of Americans worried about climate change before Trump’s election; that number is now approaching 70 percent. The Obama administration had signed international climate accords and pushed the Clean Power Plan to rein in carbon emissions, giving the appearance of progress on the issue. By shattering those relatively modest efforts, Trump and his allies may inadvertently have convinced more Americans to support climate action.

Americans, like other animals, occasionally devour their young. The last two decades of policy have not been kind to millennials. Thanks to the Great Recession, they earn less money than boomers and Generation X did at their age. They’re buying fewer homes, paying off their student debts more slowly, and putting less money into their savings. Millennials enjoy far less economic and social stability than their parents did, and it’s taking a psychic toll. Oh, and the world is ending.

There’s a cottage industry, especially within conservative circles, that tries to blame young Americans for their own problems. Millennials are cast as lazy, coddled, and censorious, thus the supposed proliferation of “safe spaces” and “trigger warnings” on college campuses and the push for better labor conditions in the workplace. Fox News, whose average viewer is 65 years old, is particularly fond of describing young Americans as naive and out of touch. This backlash is nothing new: A Gallup poll after the Kent State shootings in 1970 found that 58 percent of Americans blamed the students after National Guard fired into a crowd of protesters, killing four students.

Americans’ views on climate change vary significantly by age. A January survey by Data for Progress found that a majority of millennials and Generation X support the Green New Deal, while a majority of boomers and the Silent Generation oppose it. The generational divide is even apparent among conservatives. In a May 2018 Pew survey, only 44 percent of Republican millennials said they wanted to expand offshore oil and gas drilling compared to 71 percent of Republican boomers. A similar gap—43 percent of young Republicans versus 73 percent of older ones—emerged on support for expanded coal mining. What explains this stark age gap? Older Americans tend to be more conservative in general, and they would bear the highest costs for combating climate change while seeing the least benefit from them.

Like the Vietnam protesters of the ’60s and ’70s, millennials have shown a knack for mass organizing. Students at Stoneman Douglas High School in Parkland, Florida, led nationwide protests against gun violence after 17 of their classmates were massacred last year. The March for Our Lives last year became one of the largest national demonstrations in U.S. history, drawing almost 200,000 people in Washington, D.C., alone. Thunberg, the 16-year-old activist who spoke at Davos, cited their work as an inspiration for the student strikes.

What’s more, young also seem to have avoided some of the pitfalls that anti-war protesters fell into almost 50 years ago. Young people also seem to understand that they need to wield political power through the governing process, not just outside of it. Trump’s presidency prompted hundreds of Democratic millennials to run for elected office, including Alexandria Ocasio-Cortez, the youngest woman ever elected to Congress and the Green New Deal’s highest-profile champion. 

Millennials also seem to have rejected violence as a political tactic. Though the anti-war movement as a whole wasn’t violent, parts of, notably the Weather Underground, committed domestic terrorism. It was also a remarkably violent era in general: The FBI tabulated more than 2,700 bombings in the U.S. in an 18-month span between 1971 and 1972. That helped fuel an electoral backlash from moderates and conservatives, aiding Nixon’s election bids in 1968 and 1972. The anti-war movement ultimately succeeded in shifting public opinion against the war, and Nixon—fresh off his reelection rout of George McGovern, who had advocated for immediate withdrawal—wound down America’s involvement in Vietnam. But the cost was a generational shift toward conservatism.

The Vietnam War was a clear mortal threat to young people, tens of millions of whom were eligible to be drafted; nearly 60,000 Americans were killed in the conflict. Climate change presents a different sort of threat to millennials. It’s less immediate than an ongoing war, less visceral than being shot at. But ultimately it will prove more catastrophic. Even if drastic action is taken over the next decade, the impact of rising global temperatures on civilization will dwarf the Vietnam War’s bloodshed. The World Health Organization has projected that come 2030, climate change will cause an additional 250,000 deaths per year.

Combatting climate change will take much more effort than ending the Vietnam War, and much longer. It will require a mass movement unlike any America, or even the world, has ever seen. It will also require millennials to succeed where the anti-war left failed a half-century ago: at the ballot box. There can’t be meaningful action as long as climate deniers and slow-walkers are in charge in Washington. The challenge will be to convince enough older voters that global warming is every bit as frightening to millennials as the Vietnam War was to boomers.

“Adults keep saying, ‘We owe it to the young people to give them hope,’” Thunberg, who was nominated Wednesday for the Nobel Peace Prize, said in January. “But I don’t want your hope. I don’t want you to be hopeful. I want you to panic. I want you to feel the fear I feel every day. And then I want you to act. I want you to act as you would in a crisis. I want you to act as if our house is on fire. Because it is.”