You know when you remove a weight from an elastic surface and it bounces upwards? Now imagine that this surface is the size of a continent. That's what's happening in Antartide. As the ice melts, the land beneath it rises. And this “rebound,” a geophysical analysis tells us, could change everything we thought we knew about the future of our oceans.
This process, known as post-glacial uplift, is happening in Antarctica at an astonishing rate. According to new research published in Science Advances (I link it to you here), the phenomenon could have a significant impact on future predictions of sea level rise.
The importance of Antarctic geophysics
La Dr. Natalya Gomez, glaciologist of McGill University, highlights the importance of understanding this phenomenon: “With nearly 700 million people living in coastal areas and the potential cost of sea level rise potentially reaching trillions of dollars by the end of the century, understanding the domino effect of melting Antarctic ice is crucial.”
The research team examined the Earth's mantle beneath the Antarctic ice sheet, finding that it is particularly "soft" in some key areas. And this high viscosity is the cause of a rather rapid rise of the soil.
Surprising speed of change
La Professor Terry Wilson, a geologist at Ohio State University, explains:
Our measurements show that the solid earth that forms the base of the Antarctic ice sheet is changing shape surprisingly quickly. The rise of the land due to the reduction of ice on the surface
it is happening in decades, rather than thousands of years.
The researchers used 3D models to simulate sea level rise due to changing Antarctic land mass under different scenarios. If global warming levels are kept low, Antarctica could contribute to sea level rise of up to 1,7 meters by 2500. However, if global warming continues unabated, this number could be as high as 19,5 metres.
Cities like Shanghai, Mumbai, New York, Amsterdam and our Venice would be submerged.
Shaina Sadai )
The delicate balance between melting and rising
Il Professor Rob DeConto, a glaciologist at the University of Massachusetts, explains that when the retreat of the ice sheet exceeds the rate of rise, more water is expelled into the oceans. However, if we can slow this melting, rising land will lift some of the ice out of warmer ocean waters, allowing it to be stored longer.
It is important to note that the impact of sea level rise will not be uniform across the world. Due to gravitational, rotational and geological peculiarities, different parts of the planet will experience unique effects.
Climate injustice
Gomez and his team highlight one aspect of climate injustice that emerges from the geophysical analysis:
Low-latitude islands and coastal sites already experiencing sea level rise will experience above-average rise associated with Antarctic ice loss, regardless of the ice loss scenario. This highlights climate injustice towards nations whose emissions are low, while their exposure and vulnerability to sea level rise are high.
The importance of more accurate forecasts
The researchers warn that there are still many uncertainties in the model, particularly due to the lack of seismic data from West Antarctica. Furthermore, these estimates do not take into account what is happening with the ice in Greenland and in the world's mountains.
Professor Wilson emphasizes the importance of continuing to improve our ability to make more confident predictions: “This is the only way that will allow us to take care of our future in a meaningful way.”
Anyway, the effects of sea level rise they are already visible in some parts of the world. For example, in the Kiribati islands, villages are fighting the advance of the ocean with sandbags, which are often swept away, causing flooding and contamination of soil and water sources with salt.
Antarctic geophysics of the future, conclusion and future prospects
Gomez and his colleagues conclude that reducing greenhouse gas emissions will allow solid Earth rebound to play a greater role in preserving more of the Antarctic ice sheets, avoiding the worst and most inequitable impacts of future climate change on global coasts.
This research not only sheds new light on the complex interplay between geophysics and climate change, but also highlights the urgent need for global action to mitigate the effects of global warming. The future of our planet and its coasts depends on the decisions we make today.
