We know more than ever before about when the ice will melt and whether we can stop it

Our Year in Review series examines the most important trends, people and companies within science and technology in 2023.

The polar ice is talking to us. Shouting at us, even — practically screaming.

If we don’t listen to its cries for help, it’ll soon melt away forever. And even if we do, there’s a good chance a big chunk will vanish anyways.

“Most of the current research paints a very dark future for the whole cryosphere,” said Nils Bochow, a doctoral research fellow at the Arctic University of Norway, the world’s northernmost university above the Arctic Circle in Tromsø.

This past year, that research has cascaded in from both poles, an avalanche of bad ice news that has begun to cement answers to some of the most existential of climate change-related questions: When will the ice melt? And can we stop it?

The most dire of all climate change impacts lies in the ice sheets of Greenland and Antarctica. If they melt, dozens of feet of sea level rise will follow, swallowing up many of the world’s coastal cities — reshaping the map of the world. And our understanding of how that melt will progress is improving all the time.

“Models are getting better, we understand key physical processes better, and so the uncertainty in their future contribution to sea level is reducing,” said Mathieu Morlighem, an earth sciences professor at Dartmouth University. “We know that Greenland and West Antarctica are going to continue to lose mass, very likely at an accelerating rate over the coming decades.”

The Increasingly Precarious Future of the Polar Bear
Jane Curtin Admits Original ‘SNL’ Was ‘Terrible’ Upon Rewatch
Polar Bear Study Shows How to Close Major Loophole in Endangered Species Act
Greenland’s Northern Ice Shelves Shrunk by a Third in 45 Years. Here’s Why That Matters
Earth’s Ice Is Almost Certainly Doomed
Viral NPC Livestream TikToker Pinkydoll to Release Single Titled ‘Ice Cream So Good’

The ice sheets are truly massive, though, and there is a lot of delay built into the system: Greenhouse gasses we emitted during the last few decades and continue to pump out today will warm the planet and lock in ice sheet melt that will take many years to arrive. “Even if we stop burning fossil fuels today, it would take centuries for the ice sheet to reach a new equilibrium,” Morlighem said.

That inertia offers both doom and hope. A study published by Bochow and his colleagues in October found that the Greenland ice sheet could tip past the point of total loss at between 1.7 and 2.3 degrees Celsius of warming — not all that far off from the 1.2 degrees we have seen so far or the 1.5 degree Paris Agreement target that many scientists now think is inevitable. Greenland’s melted ice alone would raise sea levels more than 20 feet, so this could be catastrophic — only there’s a bright side, in that the researchers found bringing temperatures back down below those levels would actually stave off the sheet’s complete collapse. It is likely that at least several feet of sea level rise are coming no matter what though, probably by the end of this century.

On the other side of the planet, the speed of the West Antarctic ice sheet’s melt may have previously been underestimated. Researchers showed that models of the ice sheet were omitting a key bit of data regarding melting water underneath the glaciers — including the foreboding Thwaites, nicknamed the Doomsday Glacier because of its potential to accelerate collapse of the entire sheet.

“In the scientific community there is certainly a general feeling that we'd have to be very lucky to preserve West Antarctica in anything like its current form,” said Kaitlin Naughten, a researcher at the British Antarctic Survey. Her team added more fuel to the fire this year, with a study showing that loss of the West Antarctic ice shelves — the floating extensions of the ice sheet itself that help keep the sheet from melting into the sea — is “unavoidable” at this point.

Wind howls across the landscape north of the Arctic Circle across the Alaskan tundra on May 1, 2007 in Kaktovik, Alaska. — Jeff Hutchens/Getty Images

“The climate change we've already caused has probably locked in a delayed response which will take centuries or millennia to fully play out: ocean warming, accelerating ice loss and sea level rise,” she said.

Another study published in October that used satellite imagery to measure those Antarctic ice shelves found they have already dumped an alarming amount of water into the ocean: 7.5 trillion metric tons of it between 1997 and 2021. Antarctica’s sea ice also caused a stir this summer — winter, in the southern hemisphere — when it cratered to an astonishing record low. It has since recovered somewhat, but there is no doubt that the frozen continent is experiencing a new normal.

The ice shelf and ice sheet findings should spur action — though it might be hard to come by. “The risk of West Antarctic collapse is sufficiently high that it is sensible to plan for it,” Naughten said. “However, the bulk of the changes will happen after our lifetimes (next century and beyond), and it can be hard for policymakers to think this far in advance.”

Even the ice previously considered more stable took some hits from the science this year.

Back in Greenland, the ice shelves around the island’s northern edge were thought to be at lower risk than other parts of the ice sheet. But not so: According to another study, the shelves extending from eight glaciers have lost 35% of their volume since 1978, and the rate of melt there is accelerating. This again was largely due to a better understanding of what’s known as basal melt, or melting at the base of the ice where they touch the warming ocean waters.

And it’s not just the ice sheets, either. We have increasing evidence that the permafrost covering huge swathes of Siberia and Canada is at risk of melting, potentially releasing enormous amounts of greenhouse gasses with it. Even the glaciers of the highest mountains on Earth are struggling, with the ice on the route up Mt. Everest retreating in dangerous fashion.

“The cryosphere is in a bad state and it’s only getting worse,” Bochow told The Messenger. “Unfortunately, it is hard to stay optimistic.”

While this was clearly a very bad ice year, the scientists stress that it is no time to give up on trying to save it.

“There are a lot of ways in which we are about to cross — or have already crossed — tipping points for the ice sheets, but the rate at which things happen after the tipping point depends a lot on how much we keep pushing the system going forwards,” said Benjamin Smith, a researcher at the University of Washington’s Polar Science Center.

In other words, even “locked in” or “unavoidable” ice loss isn’t a reason to stop trying to fight climate change. The speed of ice sheet melt will vary dramatically depending on how the world’s emissions shape up over the next few decades. A lot of the world’s coastal areas are going to face some form of sea level rise disaster, but there’s a big difference in the response if it will happen by the year 2100 or by 2400.

Beyond just slowing emissions, some scientists are now starting to think about alternative responses to the ice crisis. “In the near future, and maybe already today, we might need to really consider geoengineering approaches,” Bochow said. He’s talking about controversial ideas like solar radiation modification, where many tons of small aerosol particles could be used to cool the planet and potentially slow the melting ice.

A less radical move: take the tepid victory from this year’s global climate summit, COP28, and run with it. A rapid transition away from fossil fuels could still theoretically limit warming to somewhere between 1.5 and 2.0 degrees, which might make a huge difference to the ice sheets and the billions of people who live on or near the coasts. Allowing the target to slide backward means accepting an increasingly melted world.

“Agreeing on a long-term 2 degree warming goal,” Bochow said, “instead of 1.5 degrees equals most likely large-scale defeat for the cryosphere.”

Dave Levitan

This Was a Terrible, Horrible, No Good Year for Polar Ice