“Where is that girl?” wonders aloud a teenager, still wearing her public school uniform from this morning..

“What girl?”

“You know!” Her friends look puzzled for a moment, then relax in recognition.

“Yeah, yeah. That girl.”

A few minutes later, a slightly higher-information group of boys begins to chant in a mock Swedish accent, “Greta! Greta!”

Every time the police press us to move to the sidewalk, some in the crowd imagine that we’re about to see Greta Thunberg, the 16-year-old from Sweden who has inspired millions of other kids around the world to skip school on Fridays to protest their governments’ failure to act to stop climate disaster.

Today’s climate strike drew millions around the world and across the United States. New York City’s was the biggest in the US yet, with probably as many as 70,000 people in the streets. The excitement of having Greta Thunberg here in New York today was a big part of the reason. It also helped that the New York City public school system allowed students to skip school without penalty, resulting in perhaps the most working-class and diverse climate march the United States has ever seen. But the numbers were also due to the momentum of the movement Thunberg has inspired.

Movements are collective, but some people have the right personality to lead at the right time. Who believes socialism would be as popular in the United States right now if Bernie Sanders hadn’t run for president in 2016? The historical conditions are right, but people also need leaders. Thunberg is such a person. There’s no question that she’s a huge part of the reason why people are getting into the streets, and why even politicians and the media are beginning to take this issue more seriously.

Thunberg is autistic. As Slavoj Žižek has pointed out, this is probably part of her appeal. Thunberg refers to her autism as a “superpower,” and it just might be. Autistic people often struggle to read social cues. This shouldn’t be idealized; it makes life tough for them, and our society isn’t always tolerant of such differences. For a climate spokesperson like Thunberg, however, it’s not hard to see how autism might help.

Most people, especially girls, are socialized to make other people feel good, to be nice, not to be a bummer. It’s impossible to call attention to a threat to human civilization under such social constraints. Our own possible extinction does not make anyone feel good. In addition, most of us are socialized to tell other people that they are doing a great job, or at least to find ways to emphasize the positive. But, again, it is impossible to tell the truth about climate that way. This week, Thunberg bluntly told members of the US Congress, to their faces, to stop kissing her ass. “Please save your praise,” she said. “We don’t want it. Don’t invite us here just to tell us how inspiring we are because it doesn’t lead to anything.” She said, “I know you are trying but just not hard enough. Sorry.”

Autistic people can often focus phenomenally well on one subject. (This can make them unusually productive workers, some employers have found.) Thunberg is unusual for a contemporary activist in that she rarely mentions other issues. ADHD is the neurological metaphor of our internet age; there are so many problems commanding our attention, while our contemporary ways of consuming media — constant notifications on our phones, tweets — discourage us from giving any of them the sustained attention they need. Perhaps a dose of autism is just the right antidote to our collective ADHD.

Like anyone with such a massive impact on the political culture, Thunberg has her detractors. It’s not surprising that most of them are on the Right, just where we would expect to find climate deniers who hate disabled children. But there’s also been some backlash against her from the left.

Some comes from those weirdoes for whom no human is ever self-denying enough. Thunberg, being a principled climate activist and taking seriously her role as an example to others, does not take planes; air travel is the most carbon-abusive form of transit. In order to come to New York for the UN Climate Summit (and Climate Strike) this month, then, she travelled by boat. Some of Thunberg’s most ascetic critics were angry that the adults who skippered the boat planned to travel back to Europe by plane. Others were upset by photos of disposable plastics aboard the boat. This is environmentalism as punishing neurosis rather than politics.

Other Thunberg critics, coming from a quite different political outlook, are nevertheless equally wrong: they’re upset that the zero-carbon boat is so expensive, emphasizing, with dopey populist resentment, that it’s a “yacht.” To such left critics, Thunberg is the face of an “elite” environmental movement. They suspect she is too foundation-friendly and too beloved by the media to do any good. They’re positive she can’t be for real, that she must be a manufactured phenomenon. These criticisms seem to miss the point almost as much as those of the nitpicky plastic-obsessives.

I have no doubt that the zero-carbon vessel is expensive. In fact, I hope it is; what parents would let their kid cross the Atlantic in a cheaply made rowboat? Besides, it certainly didn’t look like a luxurious journey. As for the idea that Thunberg is embraced by elites and the media, what is the implication? That she’s trying to distract us from joining the more radical, grassroots environmental movement that would otherwise be bombing ExxonMobil headquarters and kidnapping the Koch brothers? To anyone who has been watching closely as the mainstream environmental movement cozies up to the worst companies and politicians, fundraising off the plight of the cutest endangered animals while entire ecosystems are imperiled, that’s a darkly laughable fantasy.

Greta Thunberg keeps telling adults — frankly, relentlessly, not making it easy — that she can’t save us. She’s right. We need to remake our entire society. But she’s grabbed our attention and set us an example, and we needed that. At the Climate Strike today, there were many fine signs. Some would make anyone laugh who has ever been a kid, like “Keep the Earth Clean, It’s Not Uranus.” Others, like “Compost the Rich,” proposed judicious solutions. Some were heartbreaking: “I’m Studying for a Future that Has Been Destroyed.” One of the best bore a quote from Greta Thunberg: “I Want You to Panic.” That’s probably not something a “normal” person would say.