Scientists Have Determined When The "Doomsday" Glacier First Started Melting and Why

In Antarctica, the Thwaites Glacier has become known by a rather ominous name: the “doomsday glacier.” Basically, if the doomsday glacier melts, the sea level rise would be so significant that it could set off a number of other reactions, including putting coastal communities at risk.

For its intimidating nickname, people are constantly curious: is the doomsday glacier really at risk of melting anytime soon? In 2024, scientists have also discovered evidence for when the glacier started melting and why. Keep reading for everything you should know about the infamous "doomsday glacier," explained.

The Thwaites Glacier, located in West Antarctica, is huge — it’s about the size of Florida. According to a report published in December 2021 by the CIRES at the University of Colorado Boulder, a particular ice sheet of the Thwaites Glacier that floats above an underwater mountain, is at risk of shattering, posing “the biggest threat for sea-level rise this century.”

BBC News added that the doomsday glacier is already releasing about 50 billion tons of ice into the ocean annually — that’s about 4 percent of worldwide annual sea level rise, according to the CIRES report.

Additionally, a September 2022 study published in the journal Nature Geoscience observed the Thwaites Glacier over the course of 5.5 months. It found that the Thwaites grounding zone retreated at a rate of greater than 2.1 kilometers each year. That is double the rate that satellites observed from 2011 to 2019.

Overall, the authors of that study believe that over the past 200 years "sustained pulses of rapid retreat have occurred at Thwaites Glacier," and more of these pulses will likely continue to occur in the future, causing the glacier to retreat even more.

If the glacier were to melt completely, it would cause global sea levels to rise by 65 centimeters (about 25.6 inches, or just over 2 feet), which would be catastrophic.

As explained by ScienceAlert, if the glacier really melted, it could set off a chain reaction of its neighboring glaciers melting too — which would only increase the sea level rise, potentially by several meters. If that happens, many of the world’s major coastal cities would feel the effects, including New York, Miami, Mumbai, Shanghai, and Tokyo. These events could also “swallow” some low-lying islands, essentially causing them to become submerged underwater.

Not to mention, sea level rise has a number of negative effects on the ocean itself, marine life, and underwater ecosystems.

“Thwaites is the widest glacier in the world,” stated Ted Scambos, a coordinator for the International Thwaites Glacier Collaboration and a senior research scientist at CIRES. “It’s doubled its outflow speed within the last 30 years, and the glacier in its entirety holds enough water to raise sea level by over 2 feet. And it could lead to even more sea level rise, up to 10 feet, if it draws the surrounding glaciers with it.”

Research published in the Proceedings of the National Academy of Sciences on Feb. 26, 2024, that isn't yet available to the public, but has been reported on by CNN, stated that scientists spent time analyzing sediment from the ocean floor. They determined that the glacier likely began melting during the 1940s after a strong El Niño.

Unfortunately, since then, the glacier has been unable to recover, which scientists also theorize is the result of global warming.

The warming ocean is what’s melting ice beneath the Thwaites Glacier.

This too-warm ocean water is “attacking this glacier from all angles,” explained Erin Petitt of Oregon State University, as per CIRES. As the water melts the ice on the underside of the glacier, the glacier “loses its grip” on the underwater mountain that it rests on.

But what causes excess warming in the ocean? That would primarily be greenhouse gas emissions, as noted by the IUCN. A few other factors directly contribute to rising ocean temperatures as well, including overfishing.

In February 2023, two studies published in the journal Nature revealed some more detailed findings on exactly what is causing the doomsday glacier to melt. The researchers behind these studies used an underwater robot and data-gathering instruments, which were able to capture the most up-close look of the underside of the Thwaites Glacier in history.

The research helped clarify some information about which parts of the glacier are more sensitive and melt at higher rates; predictions of what will happen to this massive glacier in the future; and how the glacier will affect sea levels.

However, co-author Peter Davis stated that overall, the research presents “neither good news nor bad news” about sea-level rise caused by the Thwaites Glacier, which "is still moving as quickly as it ever has been," as per Nature.

As Petitt stated in December 2021, the floating portion of the doomsday glacier probably only has a “few years” left before it completely melts. But as for the entire doomsday glacier, we can expect “major ice loss” over the next “several decades to a few centuries,” according to CERES via Anna Crawford, a researcher who studies ice cliff failure at the University of St. Andrews.

"I visualized it somewhat similar to a car window where you have a few cracks that are slowly propagating, and then suddenly you go over a bump in your car and the whole thing just starts to shatter in every direction," added Petitt in a press conference, as per USA Today.

The climate crisis keeps getting worse before our eyes — and the only way to stop it is with climate action, especially by world governments and industry leaders.

This article, originally published on Jan. 5, 2022, has been updated to include new research.