The Rapidly Melting Ice Shelves of Antarctica - Effects of Global Warming

Friday - October 13 2023, 10:19 UTC - 1 year ago

As the Earth battles with climate change, researchers have discovered that 71 of the 162 ice shelves surrounding Antarctica have reduced in volume over a span of 25 years, resulting in a net loss of 7.5 trillion tonnes of meltwater into the oceans. Factors contributing to this have been attributed to human activities driving global warming and changes in the ocean current towards the western side of the planet. The reduction of ice shelves affects Earth's gravity and reduces Antarctica's sea ice cover, resulting in the albedo effect.

As the Earth battles the consequences of climate change, ranging from heatwaves to wildfires, the planet is expected to confront additional challenges, such as flooding in coastal regions due to the rapidly melting ice sheets. Scientists claim that 71 of the 162 ice shelves surrounding Antarctica have reduced in volume over 25 years from 1997 to 2021, with a net release of 7.5 trillion tonnes of meltwater into the oceans .

A team of researchers, headed by Dr. Benjamin Davison, a research fellow at the University of Leeds, conducted a recent study on Antarctica's ice shelves. ESA’s GOCE satellite and the NASA–German Grace mission animation depicted the ice lost from West Antarctica, causing a dip in Earth’s gravity. Watch below. Their findings revealed that nearly all ice shelves on the western side of Antarctica experienced a reduction in size .

In contrast, most ice shelves on the eastern side either remained stable or expanded in volume. Scientists estimated nearly 67 trillion tonnes of ice have melted and merged with the ocean waters in the last 25 years. This was counteracted by 59 trillion tonnes of ice being added to the ice shelves, resulting in a net loss of 7.5 trillion tonnes. Davison stated: "There is a mixed picture of ice-shelf deterioration, and this has to do with the ocean temperature and currents around Antarctica .

The western half is exposed to warm water, which can rapidly erode the ice shelves from below, whereas much of East Antarctica is currently protected from nearby warm water by a band of cold water at the coast."As a landmark 50 times the size of the UK, Antarctica's surrounding oceans experience different currents. For instance, the western side of the water moves in a different direction compared to the eastern side .

As a result, these movements drive the warmer water beneath the ice shelves in the western part, contributing to the melting of the ice from below."We expected most ice shelves to go through cycles of rapid, but short-lived shrinking, then to regrow slowly. Instead, we see that almost half of them are shrinking with no sign of recovery," noted Davison.Human-induced climate consequencesAdditionally, Davison attributed the responsibility for the loss of ice to human activities driving global warming, as the natural variation in climate patterns would indicate signs of regrowth on these western ice shelves .

The study explained that the ice shelves are giant bodies of ice floating in the seas surrounding Antarctica, extending from the continent's ice sheet covering a significant portion of the land.A statement by the scientists referred to the "ice shelves acting as giant "plugs" at the end of glaciers, slowing down the flow of ice draining into the oceans." If the ice shelves become thinner or smaller, these natural barriers – ‘plugs’ weaken .

Consequently, the glaciers lose ice at a faster rate.The team studied over 100,000 satellite radar images to estimate the ice shelf loss in Antarctica. The data was collected from mainly CryoSat-2 and Sentinel-1 satellites. CryoSat-2 was the first of the European Space Agency Explorer missions to focus on studying ice, while the Sentinel-1 mission was formed to collect imagery of the Earth surfaces .

The teams used their visibility to study the changes and losses of the ice shelves around Antarctica.