A safety band around Antarctica, holding back the ice
From a laboratory in Paris, scientists have modeled the long arc of consequence stretching from today's smokestacks to tomorrow's submerged coastlines — a study in how the choices of one era become the geography of another. A Sorbonne University team, publishing in Nature, has found that under high-emission scenarios, nearly 60 percent of Antarctica's ice shelves could collapse by 2300, unlocking a 10-metre rise in sea levels that would redraw the world's maps and displace hundreds of millions. The ice shelves themselves are not merely frozen scenery; they are the restraining walls of a continent, and their loss would release forces that no future generation could reverse. The researchers offer not a verdict, but a conditional: the outcome still depends on decisions being made right now.
- A peer-reviewed study in Nature has placed a number on civilizational risk — 38 of 64 Antarctic ice shelves gone by 2300 if the world continues on its current emissions path.
- The ice shelves act as a brake on Antarctica's interior glaciers, and once that brake is removed, the resulting sea-level rise of up to 10 metres would be effectively irreversible on any human timescale.
- The most catastrophic changes are projected to accelerate between 2085 and 2170 — a window close enough that children born today may witness its opening decades.
- London, Miami, Shanghai, Venice, and dozens of other coastal cities face partial or total submersion, with entire nations like Bangladesh reduced to fragments.
- Researchers stress their projections are conservative — real-world collapse could arrive sooner — and frame emissions reduction not as idealism but as the only available exit from this trajectory.
A research team at Sorbonne University has published a study in Nature that maps two radically different futures for Antarctica — and, by extension, for human civilization. Led by Clara Burgard, the work examined all 64 of the continent's ice shelves under both low- and high-emission scenarios stretching to the year 2300. The findings are stark: keep warming below 2 degrees Celsius and only one shelf faces serious collapse; allow warming to reach 12 degrees and 38 shelves disappear, triggering a 10-metre rise in global sea levels.
The significance of ice shelves is easy to underestimate. They are not the dramatic glaciers of popular imagination but the floating edges of the Antarctic ice sheet — a structural safety band that holds back the continent's interior ice from flowing into the ocean. When they collapse, that restraint is gone, and the resulting surge of grounded ice accelerates sea-level rise far beyond what the shelves themselves would cause by melting.
The human cost written into these projections is almost too large to absorb. In Britain alone, Hull, Glasgow, Bristol, Cardiff, and large parts of London would be submerged. Europe's coastline from Calais to Denmark would vanish underwater, taking Venice, Lisbon, and Seville with it. In Asia, Bangladesh, Shanghai, and Ho Chi Minh City face erasure. Florida, Louisiana, and Texas would be transformed beyond recognition, with Houston, New Orleans, and Miami effectively lost.
The researchers are careful to note that their estimates are conservative — actual collapse could arrive earlier than modeled, depending on how individual shelves respond to rifting and calving. But they are equally careful to frame this not as prophecy but as a conditional warning: the worst outcomes are not inevitable. They remain, for now, a matter of choice.
A team of researchers at Sorbonne University in Paris has modeled a future that reads like catastrophe: nearly three-quarters of a century from now, up to 59 percent of Antarctica's ice shelves could simply vanish. If that happens, the world's oceans will rise by 10 metres—32 feet—enough to drown entire cities and displace hundreds of millions of people.
The study, led by Clara Burgard and published in Nature, examined 64 Antarctic ice shelves under two competing futures. In a world where emissions are kept low and global warming stays below 2 degrees Celsius by 2300, only a single ice shelf faces serious risk. But in a high-emissions world—one where warming reaches 12 degrees Celsius—38 of those 64 shelves would collapse. The difference between these two scenarios is not a matter of chance. It is a matter of choice, the researchers argue. The emissions we produce now will determine whether most of Antarctica's ice shelves survive the next three centuries.
Why does this matter? Ice shelves are not the dramatic glaciers of popular imagination. They are the floating edges of the Antarctic ice sheet, and they function as a brake on the continent's interior. As the researchers explain it, these shelves restrain the flow of grounded ice toward the ocean—they are, in their words, a safety band around Antarctica. When they thin and collapse, that restraint vanishes. Ice that was held back begins to pour into the sea, accelerating the rise in sea levels far beyond what the melting shelves alone would cause.
The timeline is both distant and urgent. The year 2300 feels abstract, almost unreal. But the researchers found that the most dramatic changes would occur between 2085 and 2170—a window that some people alive today might live to see. And they emphasize that their projections are conservative. Actual collapse could come sooner, depending on how individual shelves respond to rifting, calving, and other forms of damage.
The human geography of this future is stark. In the United Kingdom, Hull, Glasgow, Bristol, Portsmouth, Southend-on-Sea, Middlesbrough, Blackpool, and Cardiff would be submerged. Large sections of London—Hammersmith, Greenwich, Southwark, Westminster—would disappear beneath the Thames. Across Europe, the entire coastline from Calais to Denmark would be underwater. Venice, Lisbon, Seville, and Montpellier would vanish. In Asia, much of Bangladesh would be gone, along with Shanghai, Ho Chi Minh City, and Karachi. In the United States, Florida, Louisiana, and Texas would cease to exist as we know them. Houston, New Orleans, and Miami would be forced inland or abandoned entirely.
The scale of displacement is almost incomprehensible—hundreds of millions of people in coastal cities across multiple continents. Yet the researchers frame their findings not as a prophecy but as a warning with an escape clause. The collapse of Antarctic ice shelves is not inevitable. It depends on the choices made now about greenhouse gas emissions. A world that commits to sharp reductions in emissions could preserve most of these shelves and avoid the worst of the sea-level rise. A world that does not will face consequences that reshape the map itself.
Notable Quotes
Current choices to change emission pathways could significantly affect the likelihood of the long-term loss of most Antarctic ice shelves— Sorbonne University researchers, led by Clara Burgard
The estimate is on the most conservative side, and actual thinning, retreat or collapse could occur sooner depending on the vulnerability of a given ice shelf— Study authors
The Hearth Conversation Another angle on the story
Why does the collapse of Antarctic ice shelves matter more than, say, melting glaciers elsewhere?
Because ice shelves act as a cork in a bottle. They hold back the much larger ice sheet behind them. When they collapse, you don't just get the water from the shelf itself—you get the accelerated discharge of all the ice they were restraining. It's a cascading effect.
The study says 2300 is the target year, but also mentions 2085 to 2170 as the critical period. Which timeframe should people actually care about?
Both. The worst acceleration happens in that middle window—that's when the shelves are most likely to become non-viable. But the full consequences play out over centuries. It's not a single event; it's a process that begins within living memory and continues long after.
The researchers call their own estimates conservative. What could make things worse?
Processes they didn't fully model—rifting, calving, hydrofracturing. Ice shelves can fail in ways that are hard to predict. The shelves are also vulnerable to damage from warm water underneath, from surface melt, from the way they're structured. Reality could move faster than the simulations.
If emissions stay low, only one shelf is at risk. That's a huge difference from 59 percent. Does that mean the outcome is still in our hands?
That's exactly what it means. The researchers are saying this isn't fate. It's a branching path. The choices made about emissions in the next few decades will determine which future actually happens. That's why they emphasize it so much.
What happens to the people in those cities in the meantime?
That's the question the study doesn't answer. Before the water comes, there's migration, economic collapse, political upheaval. The physical sea-level rise is just the visible part of a much larger disruption.