The city has given the green light to public school students who want to attend the Global Climate Strike on Friday, meaning as many as 1.1 million kids could flood the streets from Foley Square to Battery Park. That's where teenage climate activist Greta Thunberg will lead a rally and march on September 20th, ahead of the United Nations Climate Action Summit, which begins the following Monday.

A tweet from NYC Public Schools last week indicated that "students will need parental consent to participate," or a parent to accompany them if they are particularly young. Still, they're free to take the day off to protest: "We applaud our students when they raise their voices in a safe and respectful manner on issues that matter to them," reads a subsequent tweet.

We applaud our students when they raise their voices in a safe and respectful manner on issues that matter to them. Young people around the world are joining the #ClimateStrike this week—showing that student action will lead us forward. — NYC Public Schools (@NYCSchools) September 12, 2019

Thunberg, meanwhile, is making Friday school walkouts into a regular occurrence for students. The 16-year-old climate activist — who arrived in New York City on August 28th, after a 15-day sailing trip on a carbon-neutral yacht — launched "Fridays for the Future" in August 2018. For three weeks, Thunberg skipped the last day of every school week to sit outside Swedish parliament, a symbolic call for the adults inside to take meaningful action on the climate crisis.

The catalyzing sentiment is an increasingly common one among young people, who will have to live with the fallout from decades of irresponsible environmental policies they had nothing to do with, and so Thunberg's strikes got global attention. She has participated in at least two since docking in New York. Timed just days before the Climate Action Summit, this Friday's strike is intended to up the pressure on assembling diplomats.

"Please think about it from a bigger perspective,” she advised prospective strikers in a recent interview with Teen Vogue. “Not just from today, but imagine yourself in about 20 or 30 years. How do you want to look back at your life? Do you want to be able to say that you did fight against it and tried to push for a change early on? Or do you want to say that, ‘No, I just went on going like everyone else because it was too uncomfortable.’"

“If you can’t be in the strike, then, of course, you don’t have to,” she added. “But I think if there is one day you should join, this is the day."

New York public schools gives permission for students to leave school to participate in the global climate strike on Sept 20.

How will local governments and schools in the rest of the world respond? Time is running out...#FridaysForFuture #schoolstrike4climate #ClimateStrike https://t.co/2QSIQrj1in — Greta Thunberg (@GretaThunberg) September 14, 2019

So far, the Global Climate Strike counts over 2,500 events in 150 countries. But NYC houses an enormous school system, and the decision could help sway other cities to allow public school students to join protests: A spokesperson for the Los Angeles Unified School District told the NY Times that education officials were “still finalizing our plans," while in Cambridge, Massachusetts, City Council members planned to discuss student dismissals today.

Across the U.S., at least 800 demonstrations are planned for Friday, and you have to think a significant number of those will be kids. But please keep in mind, everyone is welcome to strike. "This shouldn't be the children's responsibility," Thunberg says, in a video announcing the strikes on September 20th and September 27th. "Now the adults also need to help us."

This story is part of the Covering Climate Now initiative by the Columbia Journalism Review.