This is really happening.

The Arctic and the glaciers are melting. The oceans are rising and acidifying. The corals are bleaching, the great forests dying and burning. The storms and floods, the droughts and heat waves, are intensifying. The farms and savannahs are parched and drying. Nations are disappearing. People are dying. Mass extinction is unfolding. And all of it sooner and faster than science predicted. The window in which to prevent the worst scenarios is closing before our eyes.

And the fossil-fuel industry—which holds the fate of humanity in its carbon reserves—is doubling down, economically and politically, on all this destruction. We face an unprecedented situation—a radical situation. It demands a radical response.

This is about waking up, individually and collectively, to the climate catastrophe that is upon us—truly waking up to it, intellectually, morally, and spiritually.

In recent years, I have come to know and work alongside some truly re-markable, wide-awake people—those I think of as new American radicals—in the struggle to build a stronger movement for climate justice: a movement less like environmentalism and more like the radically transformative movements that have altered the course of history in the past, from abolitionism to civil rights.

Of course, we must begin by acknowledging the science and the sheer lateness of the hour—the fact that, if we intend to address the climate catastrophe in a serious way, our chance for a smooth, gradual transition has passed. We must acknowledge the fact that without immediate action at all levels to radically reduce greenhouse emissions and decarbonize our economies—requiring a society-wide mobilization and a thus far unseen degree of global cooperation, leading to the effective end of the fossil-fuel industry as we know it—the kind of livable and just future we all want is simply inconceivable.

It seems fairly obvious that the reason we don’t hear politicians, or the “serious” people in our media, talking much about the true gravity of this situation is that to propose anything that would actually begin to address it with the necessary urgency at the national and global level would simply sound too extreme, if not outright crazy, within mainstream political conversation. Leave fossil fuels in the ground? Who are you kidding? Be serious.

This is the reality—or the surreality—of the historical moment in which we find ourselves. At this late hour, with the clock ticking down on civilization, to be serious about climate change—based, mind you, on what science and not ideology prescribes—is to be radical. The climate catastrophe is so fundamental that it strikes to the root of who we are: It confronts us with a kind of radical necessity—a moral necessity.

Mainstream critics will say that radicals have no “plan,” no “workable solutions.” (If you believe that, have a look at what Germany and Denmark are doing.) But it’s not the movement’s job to offer detailed policy prescriptions that fit within the confines of this country’s current politics. Given our political deadlock, the movement’s job is to tell the truth, however extreme—and to force those in power to recognize that even the outer limit of what our current politics will allow (a modest carbon tax, for example) is utterly inadequate to the crisis. The movement’s job is to force that reckoning.

On September 21, 2014, some 300,000 people converged on the streets of Manhattan for the historic People’s Climate March, demanding serious action from world leaders. One of the slogans for the march was “To change everything, we need everyone.” I couldn’t agree more. But here’s what would really change everything: first acknowledging that the mainstream, Washington-focused environmental movement—and the mainstream, Big Green “climate movement” that grew out of it—has failed. That we’ve already lost the “climate fight,” if that means “solving the climate crisis” and saving some semblance of the world we know. That it was lost before it began, because it got started so late. That it’s time now to fight like there’s nothing left to lose but our humanity.

* * *

Yudith Nieto, an organizer with the small, grassroots Texas Environmental Justice Advocacy Services—or TEJAS—was 24 when I met her in Houston’s Manchester neighborhood on a hot and soupy afternoon in July 2013. Mostly Latino and overwhelmingly poor, the east-side community that Yudith calls home is surrounded by oil refineries along the Houston Ship Channel and other heavily polluting industrial facilities—a chemical plant, a tire plant, a metal-crushing facility, a train yard, and a sewage-treatment plant—and sits at the intersection of two major expressways. The people who live there breathe some of the country’s most toxic air.

Yudith got involved with TEJAS in September 2011, when its founders, the father-and-son team of Juan and Bryan Parras, rallied the Manchester community against the Keystone XL pipeline, alerting residents to the increased toxic emissions from processing tar-sands crude at the refineries, and recruiting people to testify at an upcoming public hearing on the pipeline in Port Arthur.

Yudith recalled the hearing. “We get there, and the room is full of industry people. It was really eye-opening, and painful,” she said. “They were hateful, snickering and making jokes at us.”

“I took it very personally,” Yudith said. “I was trying to represent my family, people I care about, and they had no compassion toward people who would be suffering. All they talked about was money, jobs, ‘what America needs.’ No, this is about health, communities. I looked them in the eye and said, ‘I don’t want this in my neighborhood. How are we going to survive this? We already have enough shit going on in the air. We don’t need any more.’”

Working alongside Yudith in Houston were several members of Tar Sands Blockade, the diverse group of mostly young, radical climate-justice activists who had mounted a high-risk campaign of nonviolent direct action to stop construction of the Keystone XL’s southern leg, running from Oklahoma to the Gulf Coast through East Texas. (Keystone South, as it’s known, went operational in January 2014.)

Grace Cagle, 23 at the time, was born and raised in Fort Worth. She’d been a biology major at the University of North Texas in Denton when she fell in with the folks from Rising Tide and Occupy Denton, and then helped launch Tar Sands Blockade in the summer of 2012. Grace—or Luna, as she was known in the East Texas woods where she risked her life—had taken part in a dramatic, 85-day aerial tree blockade along the pipeline route near Winnsboro. Now she sat in a chair across from me in the cramped space and fluorescent light of the TEJAS office on Harrisburg Boulevard, where she was volunteering as an intern, helping organize in the hard-hit Manchester neighborhood.

So what was it, I wanted to know, that really led her to risk her neck, 80 feet up in a tree, trying to stop that pipeline?

“What am I going to do to fix climate change?” she replied. “I’m not just going to sit in a tree. I mean, nobody buys that. I know it’s going to take massive, almost unimaginable system change—or everything’s just gonna flood.”

She agreed with me that the sort of system change required won’t happen through politics as usual. Something’s going to have to force it. “That’s what originally brought me into the organizing work,” she said.

Grace said she’d come to see two converging ideas or motivations forming in her mind. One was the urgency of the climate crisis, which led her to nonviolent direct action. The other, she said, was the experience of actually being out in the endangered landscape near Winnsboro, where the blockade began. “Just this overwhelming sense of place,” she said, “that I wanted to defend.”

“They came over the creek,” Grace said. “They had a feller buncher—it grabs the trees, cuts them, and throws them. And they’re coming like 10 feet, 20 feet away from me, practically at the base of my tree. I thought they were going to kill me…. I knew that if I moved, they were there with their machines, and they wanted to cut those trees down—and they would come through our section.”

She leaped out onto a line, dangling in a harness, so she could protect two trees at once.

“That’s when it all reconverged for me,” she said. “At that moment, I was in total solidarity with the [First Nations] people in Canada, around the mines, and the people here in Manchester.”

I asked her why it was strategic for Tar Sands Blockade to engage with TEJAS and help organize in Manchester.

“We’re organizing in Manchester because it needs to be done,” she said. “It’s not a means to an end. But it’s also one of the hot spots where it aligns with the climate work, where our goals align with community needs. I would work in Manchester even if climate change didn’t exist.”

Grace told me that the seven months she’d been working in these communities with TEJAS had changed her perspective. She understood the climate science, she said. “But even as urgent as the climate crisis is, we’re not going to solve it by ourselves. So whatever it’s going to take to be able to work with other people, even if it takes another 10 years, that’s what it takes. And that can be harder than sitting in a tree or locking yourself to something.”

* * *

“I’m both calmer now and more radical,” Tim DeChristopher said to me one afternoon in Cambridge, Massachusetts. “I mean, personally I’m more at peace now. And having gone to prison, I’m more politically radical. After spending a couple years in the custody of the government, I have a better picture of the nature of the government we have, and I’d say that it’s my goal to overthrow our current form of government.”

Tim sat across from me at a small table in the aptly named Shay’s (think rebellion), an English-style pub across the street from the Harvard Kennedy School—where one can earn a graduate degree in the administration of government. But Tim is a student at the Divinity School, appropriately located in the opposite corner of Harvard’s campus. Tim’s path to Harvard was, you could say, unorthodox. In 2011, he was sentenced to two years in federal prison for monkey-wrenching a corrupt Bureau of Land Management auction of oil- and gas-drilling leases on public land in southern Utah, winning bids worth $1.8 million that he couldn’t pay. His action and trial helped galvanize the growing climate-justice movement, and he’s become a leading voice.

“Overthrow” is a pretty strong word, I suggested.

“I mean our current system of corporate rule,” Tim replied. “I say ‘overthrow’ because I recognize that the people currently in power are not going to willingly transfer power into a democratic form. In recent history, nonviolent revolutions have been far more successful than violent ones—but it still takes that kind of pressure.”

I told Tim that it seems impossible to have an honest conversation about the climate movement without acknowledging how late the hour is. I wondered whether that had anything to do with why he’d chosen to go to divinity school.

“Why I’m here is very closely connected with the fact that we are already committed to a path of chaotic and rapid change,” Tim said.

“Our job as a movement,” he went on, “is no longer just about reducing emissions—we still have to do that, but we also have this new challenge of maintaining our humanity as we navigate this period of rapid and intense change. And with that challenge, with that job, we can’t avoid the spiritual aspect of what we’re doing. We can’t avoid talking about our most fundamental principles, and our most fundamental values, and the things that we want to hold on to the most. We can’t avoid talking about our larger worldview and our vision for the world.”

Maybe it’s understandable, I said, given the magnitude of what we’re facing, that the climate movement’s activists have resorted to telling ourselves and others certain useful fictions—that we can “solve the climate crisis” or “preserve a livable planet” without deep, radical change.

“There are very few things that make me more hopeless,” Tim said, “than a movement based on useful fictions. What’s the point of a social movement that can’t tell the truth?”

Are the fictions useful, though? I asked.

“No,” he said. “The only way in which they’re useful is to help people cling to false hope. I don’t think you can be effective at fighting the real threats that we face if you refuse to deal with the real world.”

I asked Tim what a movement that has given up such false hope would sound like. What would it say? Instead of building a movement to “solve the climate crisis,” what are we building a movement to do?

“We are building a movement for climate justice,” Tim said. “That’s still a relevant concept, a relevant goal: to defend the right of all people—and not only people of all races or nationalities, but people of all generations—to live healthy lives and have both the agency and the environment necessary to create the lives they want. We are building a movement to hold on to the things about our civilization that are worth keeping, to navigate that period of intense change in a way that maintains our humanity.”

Tim doesn’t see that kind of movement coming from the Big Green groups, which, he argued, have utterly failed.

“I think being in the environmental movement for a long time should be considered a liability,” he said. “It should be like someone who stands up and says, ‘I’ve been in Congress for 30 years’—you know, you better have a good excuse.”

I pushed back. Those people are working hard, devoting their lives, to keep fossil fuels in the ground—still our overriding moral imperative if we’re going to salvage any hope of climate justice, social justice, in the future. And in the near term, that means not only pushing from the outside; it often means working within the current political system.

“But the kind of change you’re talking about—anything feasible within the current political system—really won’t do us any good,” Tim shot back. “You’re talking about going off the cliff at 40 miles per hour instead of 60…. So, yes, the most urgent thing is keeping fossil fuels in the ground. The question is how to do that. We need a different kind of movement, a movement that’s about taking power and changing power structures on a fundamental level. And I’m saying the climate movement is not equipped for that kind of struggle. The climate movement that has grown out of the environmental movement—primarily driven by comfortable people, rich people, white people—is about keeping things more or less the same. That’s no longer the challenge that we have.

“I don’t think it’s a coincidence that it’s the groups from impoverished and oppressed areas or oppressed constituencies that are building the kind of movement we need,” Tim continued, pointing to the Climate Justice Alliance and indigenous movements like Idle No More and the people on reservations in South Dakota fighting the “black snake” (the Keystone XL pipeline), or groups in Appalachia fighting mountaintop removal. “I think it’s because they’ve experienced part of the challenge that lies ahead for all of us—when there are plenty of reasons for hopelessness, they’ve chosen to fight back.”

Holding on to our humanity in the face of what’s coming will be “a never-ending challenge,” Tim said. “We need an endless movement and a constant revolution.”