The Case of the (France-Sized) Missing Antarctic Ice

From our collaborating partner Living on Earth, public radio’s environmental news magazine, an interview by producer Aynsley O’Neill with UC Boulder senior research scientist Ted Scambos. 

Midsummer in the Northern Hemisphere marks the dead of winter in Antarctica, usually a time when temperatures plunge and the surrounding ocean ices over, nearly doubling the continent’s size. 

But this June, scientists found Antarctica’s west coast was missing a chunk of sea ice the size of France.

Ted Scambos is a senior research scientist at the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder. This interview has been edited for length and clarity. 

AYNSLEY O’NEILL: How unusual it is to see this lack of ice in midwinter?

TED SCAMBOS: Ordinarily, this area near the peninsula—that’s the part that points up toward South America on the map—that area to the west side of the peninsula has extremely low sea ice for mid-winter. There’s no ice forming along this very long coast on the western side, and that’s extremely unusual in the last 50 years or so of keeping records on Antarctica—and probably for a lot longer than that. 

What’s been going on is that there’s a very strong wind pattern that’s pushing warm air from the South Pacific into this part of Antarctica, and the ice simply isn’t forming. The other part of this, and it’s a little hard to know which comes first—they’re probably both happening together—the surface of the ocean is also unusually warm, and that also has to do with how the winds are pushing the ocean water around Antarctica. 

Ordinarily that area in Antarctica would be frozen over completely, and everything would be adapting to the fact that there’s a big ice layer over the ocean. The climate would be a lot cooler on the coast, because the air has to come from the ocean, then cross a frozen ocean for hundreds of miles, and then hit the continent. Now you’re seeing this warm, moist air come straight off the ocean and hit the continent and dump a lot of snow. 

The area south of South Africa has seen enough extra accumulation to mostly offset how much ice is being lost in some other parts of Antarctica, but we still think that there’s a slowly evolving catastrophe on the ice sheet in other parts of Antarctica. But for now the total mass is close to balanced for the last few years.

O’NEILL: When you think about how massive Antarctica is, it does make sense where you can hear that some parts were seeing more snow this season and some parts were seeing much less ice than you would otherwise.

SCAMBOS: Yes, that’s true. I often describe it as being sort of like Australia with Indonesia and New Guinea, all of it buried under ice, and different sides of it experience different circulation patterns and ocean currents. 

There’s one major current that surrounds Antarctica that goes from west to east; it’s pushed along by the wind. The name of it is the West Wind Drift, and that has a big influence on the local climate, wherever it comes up close to the coast or backs away from the coast. 

There’s also a vertical component, but deep in the ocean, different things are happening, and that’s actually the main threat for ice loss in Antarctica—the deeper ocean is more frequently moving toward the coastline of Antarctica. There’s a current that reaches the underside of the ice at depth, and for those deeper, larger glaciers that flow out toward the ocean, they’re seeing a lot more melting because of this warm ocean current that’s reaching them. That is the big problem for the long term in Antarctica.

O’NEILL: It’s so easy for us to imagine the warmth of the sun beating down on us that it’s maybe not as obvious to people that the warm ocean underneath means that the ice is seeing this from sort of all sides.

SCAMBOS: You’re right, and in fact, the part that is facing the Pacific in particular seems to be getting a lot of this deeper warm water that’s reaching the thickest glaciers, melting them and causing them to speed up, so that they flow outward and lose ice. They deflate faster than ice is replaced by snowfall in that area. 

As I said, you take Antarctica as a whole, the last few years it’s been in balance. There’s a lot of discussion about how persistent that’s likely to be going forward. But in the long term, we know from ice core records in the past ice ages and warm periods that in general, a warmer planet means a smaller Antarctica and a higher sea level, and that’s what we can anticipate in the long term going forward.

O’NEILL: A lot of your work focuses on the Thwaites Glacier, which is the widest glacier on Earth, as I understand it. It’s in West Antarctica, and it’s sometimes referred to as the Doomsday Glacier. How is the Thwaites Glacier faring in 2026?

SCAMBOS: Unfortunately, it’s right at the center of this problem I’ve been talking about, with the warm ocean water reaching the coast of Antarctica. The glaciers adjacent to Thwaites are experiencing the same thing, and their losses are not insignificant. But the way the landscape is underneath the ice sheet makes Thwaites the critical glacier for losing a huge area of ice in Antarctica. 

I like to say that it’s a slow-moving catastrophe; it’s not a doomsday, it’s more of a doomed century or two. Still, the amount of sea level rise that will occur from the loss of ice in this area—and we think it’s already underway—the models are showing that we’re committed to losing the ice. It’s just a question of whether we’re fast enough to stretch out that loss to several thousand years versus dumb enough to keep warming the planet and seeing it collapse very quickly in a century or two. 

Thwaites is really the biggest player, the biggest wild card in sea level rise in the future. Warming oceans, which makes the water expand, that’s a big part of what will happen. And, Greenland melting, especially surface melting water running off at the top of the ice sheet into the ocean—another big player. But those are fairly easy to predict and forecast. They’ll scale with the warming planet pretty predictably. Thwaites is a lot less predictable in terms of when and how this ice is really going to come off the continent.

O’NEILL: When do you feel like the rest of the world will start to feel the consequences of this rapid ice loss, whether it be the sea ice or the glacier ice?

SCAMBOS: Unfortunately, human beings need a catastrophe. A steady drumbeat of events have more or less convinced the American public that climate warming and climate change are real. I think the heat wave in Europe, heat waves in the United States, hurricanes, those things, they have a cumulative effect on opinion, and I think we’re there in the U.S., just tipping over into, “Yeah, this is really happening, and we might need to think about this sooner rather than later.”

O’NEILL: When we talk about sea level rise, you’ll always see passionate talkers from low-lying island nations where it’s quite literally their doorstep—their front yard is at risk.

SCAMBOS: Yes, the ocean is at their doorstep, and there’s an interesting reason why those islands are actually the ones that are jumping up and down the most. Sea level rise on Earth is not uniform. It won’t just be like a bathtub slowly filling up evenly around all of the coastlines. 

The areas that are losing ice the most will actually see sea level drop near those coasts. It’s a little bit complicated, but because you’re losing literally trillions of tons of ice, that continent is not pulling the ocean against the coast as much as it used to. The gravity from that ice sheet is lower than it used to be, because that mass went into the ocean. 

The net effect is that the band of the tropics around the middle of the Earth, near the equator, on either side—up to about 30 or 40 degrees latitude—both sides will see more than their share of sea level rise. Those islands in the Indian Ocean and in the Pacific Ocean are going to see about 30 percent more sea level rise than the rest of the world does. 

It’s unfortunate, and that’s why that’s such a critical problem. And they’ve got nowhere to retreat to. I mean, I don’t want to be flippant, but there’s Baton Rouge for New Orleans. There’s no higher ground for the Maldives.

O’NEILL: What’s something that you want people to keep in mind when they hear a story like this?

SCAMBOS: I realize that it’s a Debbie Downer talk to keep hammering home how at risk the future appears to be, but the fact of the matter is, we have the technology that we need in order to radically slow the pace of sea level rise and the pace of warming on Earth. 

We are committed to some warming for quite a while. But in terms of solving the issue of greenhouse gas emissions, we’re really there between solar and wind, and I don’t want to eliminate new forms of nuclear power—that may well be a part of it. We can do this without continuing to put heat-trapping gases into the atmosphere. The solution is right there in front of us.