Antarctica Ice Sheet Could Avoid Collapse, But It’s Still Vanishing. But…

A catastrophic scenario involving Antarctica’s massive ice sheet is frequently discussed in the context of climate change. The concern is that this ice sheet could eventually disintegrate, leading to disastrous consequences for global coastlines. Scientists have described this scenario as one where, after the floating edges of the ice sheets melt, only towering ice cliffs remain. These steep cliffs would be unstable, leading to massive chunks of ice breaking off. This process would continue until the entire ice sheet collapses into the ocean. If coupled with high emissions of greenhouse gases, this event could raise global sea levels by more than a foot by the end of the century.

The United Nations’ most recent sea-level rise assessment includes this scenario as a “low-likelihood, high-impact” possibility. However, this chain of events is still largely theoretical.

Now, a group of scientists suggests that this scenario might not unfold as previously imagined, and the likelihood of such a dramatic collapse may be remote. This doesn’t imply that Antarctica’s ice is immune to the planet’s rising temperatures. But according to new evidence, the feared collapse of ice cliffs, one after another, might not happen.

“The Antarctic ice sheet is going to disappear; this is going to happen. The question is how fast,” said Mathieu Morlighem, a professor of earth science at Dartmouth College and leader of the research.

What could happen to the Antarctic ice sheet?
Dr. Morlighem explains that it is still uncertain how ice will break apart under stress, meaning the timeline for action and safety measures is unclear. Regardless, the melting of this ice will significantly impact human civilization and the environment.

The study focused on the Thwaites Glacier, which is roughly the size of Florida and one of the most rapidly receding and unstable glaciers in Antarctica. The researchers ran simulations of two “worst-case scenarios” for Thwaites. The first scenario examined what would happen if the glacier’s floating edge disappeared entirely today. The second scenario looked at the effects if the ice shelf vanished in 2065. In this later scenario, the glacier would reveal ice cliffs taller than those currently near the water’s edge.

The findings showed that once the ice shelf melts away, the remaining ice also begins to melt faster and flow more quickly into the sea. However, the cliffs don’t have time to grow taller, preventing the anticipated runaway collapse.