Is Thwaites Still the ‘Doomsday Glacier’?
The term "Doomsday Glacier" may sound dramatic, but scientists are not particularly fond of this label used by the media to describe Thwaites Glacier. While it is true that this glacier is the size of Florida and its complete melting could potentially raise global sea levels by around two feet, researchers aboard the icebreaker Araon are embarking on a mission to study Thwaites and the surrounding waters. Their goal is to determine how soon we might witness a significant collapse of this crucial ice mass.
However, scientists assert that Thwaites is not destined for an inevitable demise. They highlight an important point: if we can successfully reduce carbon emissions—key drivers of climate change—we may still have a chance to save the glacier from disappearing entirely.
But here’s where it gets controversial: despite this hopeful outlook, many countries are falling short in their efforts. In fact, fossil fuel emissions reached unprecedented levels globally in 2025, showing little sign of decline. Alarmingly, some studies indicate that we may already be past the point of no return when it comes to certain ice shelves along the Antarctic coast, meaning some degree of melting might be unavoidable.
Nonetheless, other experts believe that while a total collapse of Thwaites within the next few decades is unlikely, they have gained valuable insights into what factors could trigger its disintegration later in the century or beyond.
To grasp these predictions better, it’s helpful to visualize the glacier's structure. Thwaites, like all glaciers, consists of solid ice but behaves differently due to gravity pulling it toward lower elevations, causing it to flow like a thick liquid—think of molasses. The glacier begins on the Antarctic landmass but extends far out into the ocean, where the front edge actually floats above water, creating what is known as an ice tongue.
Recently, warmer ocean currents have been lapping against the underside of this floating ice, resulting in melting and thinning. Moreover, these currents erode the base of the glacier that rests on bedrock, prompting the retreat of what scientists refer to as the grounding line—the point where the glacier meets the land. If this retreat continues unchecked, the glacier could enter a perilous feedback loop.
The underlying bedrock beneath Thwaites is below sea level and slopes downward; it becomes increasingly deeper as one moves inland. If the grounding line recedes too far, this sloping shape will facilitate the influx of warm seawater, akin to floodwaters filling a basement. This warm water would exacerbate the melting of the floating ice, leading the grounding line to retreat even further.
This self-reinforcing cycle of retreat and melt has the potential to destabilize the glacier irreversibly, resulting in large portions breaking off and melting away into the ocean. Hilmar Gudmundsson, a glaciologist at Northumbria University in England, warns, "The consequences of this unstable retreat will be felt worldwide in terms of sharply increased rates of sea-level rise."
According to a 2023 study conducted by Gudmundsson and colleagues, Thwaites has not yet entered this dangerous cycle. Yet, computer models have bolstered their confidence that such a scenario could occur if the grounding line continues to pull back excessively. "Essentially, our perspective has shifted from uncertainty to a near certainty regarding this outcome," Gudmundsson stated. However, he noted the difficulty in accurately predicting when this cycle might eventually begin.
Despite the alarming news surrounding Thwaites, not all recent studies paint a dire picture. A different recent analysis suggests that one particularly catastrophic scenario involving the glacier's ice cliffs may be less likely than previously thought. These cliffs, steep and precarious, form when chunks of ice break off and fall into the sea. As more ice detaches, taller and more unstable cliffs become exposed, potentially leading to a cascade of collapses.
Fortunately, computer modeling published in 2024 indicates that Thwaites may not be as susceptible to this specific fate, although some scientists argue that more research is necessary to confirm this finding.
While sensational, doom-laden narratives capture public attention, scientists are also dedicated to refining their forecasts regarding ongoing sea-level rises driven by Antarctic ice flows. Doug Benn, a glaciologist from the University of St. Andrews in Scotland, emphasizes the importance of understanding these gradual changes: "These incremental shifts may not make for thrilling disaster films, but they are critically important for the world’s most vulnerable low-lying nations and ecosystems."
Benn concludes, "Authorities aren’t really planning for the next century; they’re focused on the near future. That’s where our attention must turn." What are your thoughts on the future of Thwaites Glacier? Do you believe we can still avert its potential collapse, or are we already too late? Share your views in the comments!
