A global warning on global warming is taking place Friday, via protests hitting major cities worldwide. What organizers hope to make "the largest climate strike in history" will happen in 150 countries, reports NBC News, and is planned as a lead-in to Monday's UN Climate Summit in New York City. The protests' general mission: to slash the use of fossil fuels driving climate change. Environmental groups, workers from mega-companies like Amazon and Google, unions, and especially children are among those organizing walkouts locally, with the Guardian noting strikes will take place in more than 1,000 locations in the US alone. "When your house is on fire, somebody needs to sound the alarm," a joint statement by the mayors of New York, Paris, and Los Angeles reads, per the Guardian. "Young people in our cities, displaying incredible maturity and dignity, are doing just that."
At the head of the pack: Swedish teen activist Greta Thunberg, sometimes called the "Joan of Arc of climate change," who spent the early hours of Friday morning retweeting photos of protesters from cities all around the world. "We are on school strike for the climate," she says in a video in her pinned tweet. Thunberg has spent the past couple of weeks "on tour" in the US, making public appearances and meeting with big names like Nancy Pelosi and Barack Obama, per the New York Times. Vox notes Thunberg, who's set to attend Monday's summit at the UN, will be at the front of a demonstration in New York City Friday, complete with a rally and march to Battery Park. The city has given its 1.1 million public school students the OK to take the day off to participate. "If there is one day you should join, this is the day," Thunberg tells Teen Vogue. CNN is covering the global strikes live. (Read more climate change stories.)