One of the biggest simmering dangers of climate change is the rising sea level. And with the Doomsday glacier on the brink of collapse, experts fear the tumultuous tides and 60-feet rise in sea level are near today than ever before.
But what is the doomsday glacier? Why are scientists worried about it? And how big of a risk does the melting glacier pose?
What is the Doomsday Glacier?
Thwaites Glacier has an area of 1,92,000 square kilometres, almost the same size as Florida or the United Kingdom, and is highly vulnerable to climate and ocean changes. The Thwaites Eastern Ice Shelf is the floating terminus of the Thwaites Glacier, which now contributes up to 4% of global sea-level rise.
The ice shelf works as a barrier, slowing the flow of ice from the continent into the sea. The Thwaites Glacier will accelerate if this drifting ice shelf breaks apart, increasing its contribution to sea-level rise by up to 25%.
The Doomsday glacier has changed more radically than any other ice sheet and ocean system in Antarctica during the last decade, owing to human-induced climate change and rising temperature in the Earth’s atmosphere and seas.
According to The International Thwaites Glacier Collaboration, Thwaites has lost an estimated 1,000 billion tonnes (900 billion metric tonnes) of ice since 2000; its annual ice loss has doubled in the last 30 years, and it has now lost approximately 50 billion tonnes (45 billion metric tonnes) more ice than it receives in snowfall each year (ITGC).
What Will Happen if the Doomsday Glacier Melts?
If the doomsday glacier cracks and melts, the ice sheet would release hundreds of large icebergs into the Southern Ocean, posing a threat to shipping. Those icebergs, however, will have little effect on global sea levels.
This is because a section of the Thwaites glacier is now floating, diverting the same amount of seawater released when the icebergs melt. The main issue is that the floating ice is presently holding back a significant chunk of the Thwaites Glacier on land.
Scientists believe that the landlocked ice will begin to flow three times quicker than it does now when the watery component of the glacier breaks away. It will also come into closer touch with the Amundsen Sea’s comparatively warm waters, hastening to melt.
Furthermore, According to ITGC lead coordinator Ted Scambos, a senior research scientist at the Cooperative Institute for Research in Environmental Sciences, if Thwaites completely broke up and released all of its water into the ocean, global sea levels would rise by more than 2 feet (65 centimeters) (CIRES). This scenario is most likely to contribute significantly to increasing sea levels.
Other Unstable Glaciers
The ice shelf, which may be thought of as a drifting extension of the Thwaites glacier, is one of many in the Amundsen Sea Basin, West Antarctica, that scientists are keeping an eye on. Rising ocean temperatures are eroding many ice shelves that hold back glaciers in the area, including Thwaites and its next-door neighbor, the Pine Island glacier.
Warmer ocean water can penetrate these floating ice shelves, causing melting from below to thin and weaken the ice, allowing cracks and fractures to form. By ocean-driven melting at the bottom of the ice shelf, the anchoring point at which the ice contacts the seabed is also pushed backwards.
The Amundsen Sea’s bottom slopes downhill, which might ultimately create a change when the glaciers lose their foothold and recede quickly. If the ice shelves go, the West Antarctic glaciers will have less resistance, allowing them to ramp up and contribute more to world sea levels.
Scientists are still working out how to use MICI, and there are still concerns about the sustainability of West Antarctic glaciers. So while the failure of Thwaites might undoubtedly set off a chain reaction, not everyone anticipates this to happen.
The Outpouring Threat of Doomsday Glacier
Thwaites glacier already accounts for around 4% of the global sea-level increase. The glacier has lost approximately 1000 billion tonnes of ice since 2000, and this has risen continuously over the previous three decades. Its flow rate has doubled in 30 years, dumping twice as much ice into the ocean as it did in the 1990s.
However, according to other research, the disintegration of the Thwaites ice shelf and glacier may not have the disastrous consequences that some fear. Sea ice and pieces of ice that break away from the falling ice shelf and glacier might have a similar constraining effect as the entire ice shelf, halting the chain reaction and preventing the entire West Antarctic ice sheet from collapsing.
However, while it is still unclear what will happen to the doomsday glacier, one this is certain: retreating Thwaites glacier will continue to contribute to world sea level for years to come.