In a startling revelation, researchers have discovered that Antarctica’s ice shelves have been losing an astonishing amount of mass over recent decades. According to a new study led by Dr. Ben Galton-Fenzi, a principal research scientist at the Australian Antarctic Division, the continent’s ice shelves have been shedding an estimated 843 billion tonnes of mass every year due to melting from beneath.
This staggering loss is the equivalent of 843 giant ice cubes, each measuring a kilometre in length, width, and depth, all melting away. It’s a volume of water roughly equal to the annual flow of the Nile River into the ocean.
The findings, which took a decade to compile, paint a concerning picture of the rapid changes occurring in Antarctica. As global temperatures rise, the ocean’s warming is causing the ice shelves to melt from underneath, making them increasingly unstable and vulnerable to collapse.
“We need to know because the ocean-driven mass loss is one of the biggest uncertainties in Antarctica ice sheet projections and, therefore, in global sea level rise,” explains Galton-Fenzi.
The research, which brought together modelling work from nine groups around the world, highlights the urgent need to understand the complex dynamics at play beneath the ice shelves. While the edges of the shelves can calve off into the ocean, the continent also gains mass from snowfall. But the delicate balance is being disrupted by the effects of climate change.
“Knowing the role of the ocean in driving the mass loss and how that feeds back into the flow of the ice into the ocean is a key problem that a lot of nations are working on,” says Galton-Fenzi.
The findings come as scientists warn that some of Antarctica’s most vulnerable regions alone have enough ice to raise global sea levels by around 15 metres if they were to melt completely. While such catastrophic scenarios may take centuries to unfold, the researchers caution that the loss of ice is already committed to, and the consequences could be dramatic.
“It changes the map and we can’t put the genie back in the bottle,” says Dr. Steve Rintoul, an oceanographer and leading Antarctic expert at the Australian government’s science agency, CSIRO.
The challenge lies in the relative shortage of data on the conditions beneath the ice shelves, where the coldest water on Earth resides. Satellite observations and ship-based measurements are limited, and even drilling holes to access the subsurface environment is an immense challenge.
As the world grapples with the impacts of climate change, the fate of Antarctica’s ice shelves will be a critical factor in determining the future of our coastlines and the global climate system. The new research serves as a stark warning, underscoring the urgent need for action to mitigate the effects of global warming and protect this fragile and vital region.
