The outlook for “Doomsday Glacier” just got gloomier. 

Scientists are warning the Antarctic Ice Sheet, known formally as the Thwaites Glacier, will deteriorate “further and faster” and that sea level rise triggered by the melting could impact “hundreds of millions” in coastal communities.

“Towards the end of this century, or into the next century, it is very probable that we will see a rapid increase in the amount of ice coming off of Antarctica,” said Dr. Ted Scambos, a glaciologist at the University of Colorado. “The Thwaites is pretty much doomed.”

The findings are the culmination of six years of research conducted by the International Thwaites Glacier Collaboration, a collective of more than 100 scientists.

The “Doomsday Glacier,” roughly the size of the state of Florida, is one of the largest glaciers in the world. Scientists predict that its collapse could contribute to 65 centimeters, or roughly 26 inches in sea level rise.

If you account for the ice the Thwaites will draw in from the large surrounding glacial basins when it collapses, the sea level rise could be even higher. “That total will be closer to three meters of sea level rise,” Scambos said.

According to the researchers, the volume of water flowing into the sea from the Thwaites and its neighboring glaciers has doubled from the 1990s to the 2010s.

Approximately 1/3 of the front of the Twaites is currently covered by a thick plate of ice — an ice shelf — floating in the ocean that blocks ice from flowing into the sea. However, Scambos said the melting is accelerating and that the ice sheet is “very near to the point of breakup.” 

“Probably within the next two or three years, it will break apart into some large icebergs,” he said. 

This will eventually leave the front of the glacier exposed. This may not necessarily lead to a sudden acceleration in melting, but it will change how the ocean interacts with the front of the ice shelf, Scambos said.

Deep ridges that prevent ice from flowing into the ocean are on their way out. The ridges, in the bedrock below the ice sheet in Antarctica, provide a “resistive force” against the ice, Scambos said, that slows down its flow into the ocean. As the Thwaites collapses, it will lose contact with these protective ridges, causing more ice to empty into the ocean.

One of the more surprising findings to come from the International Thwaites Glacier Collaboration was how tidal activity around the glacier is pumping warmer sea water into the ice sheet at high speed. That water, which is a couple of degrees above freezing, is getting trapped in parts of the glacier and forced further upstream.

“It goes in every day, it gets squashed up under the glacier. It completely melts whatever freshwater ice it can, and then it gets ejected, and then the whole thing starts again,” said Scambos.

The new findings from the International Thwaites Glacier Collaboration add to a vast body of research on how the deterioration of glaciers worldwide could contribute to sea level rise. In May, a study found that high-pressure ocean water is seeping beneath the “Doomsday Glacier” leading to a “vigorous ice melt.”  

Study co-author Christine Dow called the Thwaites the “most unstable place in the Antarctic” and said the speed at which its melting could prove “devastating for coastal communities around the world.” 

Researchers at the University of California, Irvine predicted the ocean could rise by about 60 centimeters, or about 23.6 inches, roughly on par with the predictions from scientists part of the International Thwaites Glacier Collaboration.

Scientists also have also warned about the potential consequences if the Greenland ice sheet were to melt. Greenland’s melting ice mass is now the No. 1 driver of sea level rise, according to Paul Bierman, a scientist at the University of Vermont. If it melts completely, scientists project it could lead to 20 to 25 feet of sea-level rise.

Scambos said rising global temperatures linked to climate change have warmed oceans and generated new wind patterns that make these glaciers more susceptible to melting.

“It is very likely related to increasing greenhouse gasses in the atmosphere, which changed wind patterns around Antarctica, and therefore changed ocean circulation around Antarctica,” he said. “That’s the main culprit.”

Scientists project that without intervention, the Thwaites could completely disappear by the 23rd century.

Greenland has melted before, and as the climate warms, it will melt again — this time leading to what scientists warn could be 20 to 25 feet of sea-level rise.

During one of the warm periods within the last 1.1 million years, the center, not just the edges, of Greenland’s massive ice sheet melted away, new research has found, giving way to a dry and barren “tundra landscape” that was home to various insects and plant life. The findings were shared in a new paper published today in the Proceedings of the National Academy of Sciences. 

When the ice sheet initially melted, there were lower levels of greenhouse gasses in the atmosphere than there are today. Now with more carbon dioxide in the atmosphere, scientists say Greenland’s ice sheet is more susceptible to melting than previously thought. 

“Greenland has been around for 2.7 million years with its ice,” said Paul Bierman, a scientist at the University of Vermont who co-led the new study. “Now there’s some evidence that this ice sheet is fragile.”

The researchers have been studying materials from beneath the hood of the Greenland ice sheet, the largest in the Northern hemisphere, since 2014. They examined sediment from the bottom of an ice core — dubbed GISP2 — extracted from two miles below the surface at the center of the ice sheet nearly 30 years ago. 

The 1-ounce sample of sediment was filled with clues of Greenland’s past. Tiny little black specks, when put under the microscope, revealed an insect eye, an Arctic poppy seed, parts of an Arctic willow, and tiny bits of soil fungus and spike moss — what Bierman referred to as a “frozen ecosystem underneath the ice.”

According to researchers, the fossils provide “direct confirmation” that 90% of the ice sheet was once gone.

“Finding these fossils in the center of the ice sheet is unambiguous evidence that Greenland’s ice has disappeared [in the past],” said Bierman. “And once you lose the center of the ice sheet, you’ve lost it all.”

The findings supports what’s called the “fragile Greenland” hypothesis: that nature, outside of human influence, has caused the ice sheet to melt at least once since it formed, Bierman said. 

At 656,000 square miles, the Greenland ice sheet currently covers around 80% of the island territory. To put that into perspective, it’s about three times the size of Texas.

NASA, which has mapped Greenland’s ice loss, says the sheet has “rapidly declined in the last several years,” prompting the global sea level to rise around 0.03 inches per year. Greenland’s melting ice mass is now the No. 1 driver of sea level rise,  according to Bierman.

“In the early years of the climate warming, it was mountain glaciers that were doing most of the melting and adding water to the ocean,” he said. “Now it’s Greenland.”

While it could be a few thousand years before the entire Greenland mass melts, Bierman said, the consequences would be dire: hundreds of millions of people could lose their homes and businesses. Places we hold near and dear to our hearts would be lost.

“As I like to say when people ask me, why does it matter? I say think about your favorite beach. And then imagine your favorite beach with 25 feet of water on it,” Bierman said.