These pesky teenagers have a scheme for saving Planet Earth. It drops in September. | Will Bunch

Grown-ups, do you hear something? It’s our own children. They’ve been out there for a couple of years now, banging the drums and trying to tell us we need to do something about climate change and fixing the messed-up world that we brought them into — and yet we still haven’t listened.

So they’re about to get a whole heck of a lot louder.

“It’s very sad that the weight of the climate crisis has been put on my generation’s shoulders — that we have to organize and mobilize in order to have a future," Alexandria Villaseñor told me. "We’re finding more ways to take direct action and get attention from adults. It’s really upsetting because we shouldn’t have to do this in the first place.”

Villaseñor is 14 years old. I spoke with the New Yorker and with the main Philadelphia organizer for a planned global “climate strike” on September 20 and related protests — that would be Isaac Harte, a 12-year-old student at Delaware Valley Friends School — Thursday morning on a Zoom conference call that Villaseñor set up. It was not her first call of the morning. Helping to lead a global protest movement is hard work, especially when you’re a rising 8th-grader.

Inspired by and now closely allied with the world’s best-known youth climate activist, Sweden’s 16-year-old Greta Thunberg, America’s growing cadre of teen protesters like Villaseñor and Harte are hoping that the worldwide strike on September 20 will help this country’s burgeoning movement catch up with Europe and other nations where youth actions have drawn up to hundreds of thousands. They also want to see the climate crisis get top billing — before it’s too late.

Their climate strike will come in an America where Mommy and Daddy are too busy bickering until all hours of night and throwing pots and pans at each other to listen to their own kids.

That’s how it’s felt these last few days, with a national conversation totally dominated (and not surprisingly) by the mass shootings in El Paso and Dayton, our strange president’s role in inspiring the El Paso killer and his churlish reaction to subsequent events, and the slow parade of heartless immigration raids and a gulag archipelago on the our southern border. The yelling has kept us from noticing the fire that’s smoldering in the far corners of the house.

It was just a couple of days before the gunshots in El Paso that the dome of hot air that tortured much of northern Europe in July — with temperatures in Paris rising to a once-unthinkable 108 degrees — migrated over the massive ice sheets of Greenland. In just a few days, the Arctic island outpost lost an astronomical 60 billion tons of ice underneath that baking sun. Scientists said the melt — of an extent that climate gloom-and-doomers were predicting for the latter 21st century, not now — could cover the entire state of Florida in 5 inches of water. Those numbers — as always with climate change — can be hard to fathom but in this case a picture (or video) is worth 1,000 words.

That’s on top of the wildfires across Siberia that — thanks to record high temperatures — have already devoured forestlands roughly the size of Belgium. And then there’s the steady flow of more sweeping scientific studies warming of worldwide chaos if we don’t start taking immediate, drastic action to reduce greenhouse-gas pollution. The latest came Thursday morning when a major United Nations report on the world’s food supply came with a dire warning — both that our eating habits like high meat consumption are exacerbating global warming, while climate change will in turn lead to growing food shortages from drought, erosion and floods.

It’s enough to make a person want to yell “Enough!” — but in the age of Donald Trump, can anybody even hear you scream? That’s why a bunch of teenagers and 20-somethings — you know, the people who’ll be in their 60s and 70s in 2070, when summers could be as much as 10 degrees warmer than they were in the 20th century and the seas will be at least several feet higher — have decided to grab the torch from us folks who’ll be dead in 2070, before we burn it all down.

During America’s long hot summer of 2019, a group of climate activists like Villaseñor and Harte have been leading a series of smaller climate protests targeting the media, big corporations and universities as they build toward their goal of massive global action beginning on September 20, when kids throughout the world will be back in school. Elsewhere, the youth movement has already grown confrontational with the rise of allied groups like Extinction Rebellion, which has blocked traffic in London and elsewhere and seen its members arrested for civil disobedience.

But they’re also thinking locally, as Harte — who lives in Coatesville — helped successfully lobby West Chester’s borough council to ban single-use plastic bags and straws. The 12-year-old told me that climate activism is a way to cope with anxiety, of “worrying about what’s going to happen” after reading some of the more dire predictions.

Villaseñor founded Earth Uprising and became arguably America’s best-known youth activist after a trip to visit family back in her native Northern California, where the air was so thick with smoke from the Paradise wildfires that it exacerbated her asthma and she had to be sent back to New York. “I love my hometown, and I wanted to fight,” she said of the experience. Learning of Thunberg and her weekly strikes, she now plants herself in front of the UN with a protest sign every Friday.

“The movement is growing every day,” Villaseñor said. That will be tested next month. Organizers of the September action — centered around a UN climate summit where Thunberg is slated to speak after crossing the Atlantic in a non-polluting sailboat — are calling on adults to join in. With groups like Germany’s powerful labor unions behind them, they seem assured of their worldwide goal of millions of participants to demand a rapid transition from fossil fuels to 100 percent renewable energy, along the lines of the Green New Deal.

How much traction is the movement getting? In recent days, Thunberg has come under increasing attack from so-called adult columnists like an Australian-based writer for a Rupert Murdoch-owned paper who called her “deeply disturbed” and said the Swedish teen — who is on the autism spectrum — has “mental disorders.” A few days later, op-ed writer Christopher Caldwell lashed out in the New York Times, calling Thunberg “a complicated adolescent” and her protest movement undemocratic.

You know the old saying, that first they ignore you and then they ridicule you and then they fight you... For teen activists like Villaseñor and Harte, the grown-up freak-out over climate activism feels like the fourth stage of that parable — victory — is getting closer.

“The fact that he (Caldwell) had to write an article like that means that the student strikers are threatening to him — and we’re threatening the beliefs of so many adults and so many climate deniers and what they’ve thought for so long,” Villaseñor said. “We are winning the fight, but we have a lot farther to go...”

“There is no “parent” telling Climate Activists to do what they are doing!” Harte wrote on his Twitter feed earlier this summer. “We do it because we care about our future!” The kids are alright. You can join them at Strikewithus.org.

This month’s climate action: I’ve promised (successfully, for once) to write a column about climate change at least once every month and to add a small tip about something you can do in your everyday life to reduce greenhouse-gas pollution — a reminder that change needn’t be overwhelming. In honor of 12-year-old Isaac Harte and West Chester borough, let’s say a good word about the environmental controversy of the moment — ditching that plastic straw.

Yes, they absolutely contribute to climate change, with plastics manufacturing accounting for 6 percent of global oil consumption. Arguably worse, they’re part of the growing pile of plastic gunk cluttering the world’s oceans. And they can be replaced, with reusable, washable bamboo or metal straws. So what on earth are you waiting for?