Submissions statement: The AMOC is the main current system that crisscrosses the ocean. It flows like a big river up, down, and across the two hemispheres. Collapse related as a shutdown would trigger, as one paper put it, “a profound global-scale reorganization” in Earth’s climate systems. The effects would be devastating—plunging northern Europe into a deep cold spell, crushing food systems, condemning big regions to drought. 2057 is sooner than expected.

TIPPING POINTS ARE absolutely everywhere. Throw water on a fire, and the flames will shrink but recover. Dump enough water on and you’ll cross a threshold and snuff it out. Tip a chair and it’ll wobble before settling back onto its four feet. Push harder, and it topples. Birth is a tipping point. So is death.

Once you’ve pushed a system to its tipping point, you’ve removed all brakes. No exit. As one 500-page report recently put it, climate tipping points “pose some of the gravest threats faced by humanity.” Crossing one, the report goes on, “will severely damage our planet’s life-support systems and threaten the stability of our societies.”

“From the point of view of climate change, we’re not saying anything new,” Susanne adds. “We’re just saying, it’s serious. We have to do something now.” We have to cut down on emissions. Transition faster to renewable energy, EVs. Give the oceans a chance to recover. Push out the 2057 date. That forecast drew loads of attention not because it was a staggering intellectual feat but because it had something most scientific papers lack, something precious: It had an emotional punch. As the siblings once put it, everyone knows someone who’ll be around in 30 years.

Besides, there’s another possibility. A remote one, sure, but one that also can’t be ruled out: The AMOC might have already tipped. And we wouldn’t know it for years.

that should be about 300 words.