To at least approximately determine this, scientists need to know exactly the mass of ice covering Antarctica, and the speed of its melting.
It is believed that the ice in Antarctica has accumulated for more than 20 million years. Some of it gradually disappears into the ocean at the expense of the icebergs that are separated from the massif. But this loss is replenished by a severe snowy winter. True, it is not entirely clear to what extent. If we take into account that the average thickness of the glacial shield of the continent is 2.5 km (there are places where it reaches even 4 km!), Approximately the mass of ice is estimated at 26 million cubic kilometres.
Icebergs carry about 2.5 cubic kilometres of ice per year in the ocean. But this figure can dramatically increase because of the warming on the planet. Indeed, the icebergs became larger and they began to be broken off by larger parts (100 km or more in length!). It is clear that there is an alarm not only because of the dangers to the ships, but also concern about the rate of warming.
With the help of satellites, aerial photographs, deep echolocation by various instruments and devices, in the last two decades a detailed study of the subglacial relief of Antarctica has passed. A whole ice shield is a form of a huge dome. But somewhere the ice just barely conceals the mountains, and somewhere up to them, you can only reach by drilling several kilometres.
And although there is an opinion that the White Continent is geologically relatively quiet on the Earth, in fact, it is deceptive. Under the ice thickness, there are dozens of volcanoes. There are signs (frequent ice shakes) to the effect that they wake up and warm up the ice cover from below. In addition, more water becomes in the subglacial lakes, in which there is life at the level of microbes.
The map of Antarctica, compiled from the results of numerous scientific studies, does not cause optimism without ice.
The dark red colour indicates a rather high temperature of the interior. And this is due to the proximity of the magma to the surface. The ice shield is still "crushing" on volcanoes and mountains - they "sagged" on average by half a kilometre. This is what is holding back volcanic activity, and only one volcano Erebus is actively "working". But if the ice convergence due to melting goes even faster, then the deep part of the bowels will "straighten" and the hot magma will start to pour out, which will cause catastrophic melting of the ice.
The second significant danger here is that once Antarctica was in a zone of a very hot climate, here grew typically southern plants, warm rivers flowed, there were many all kinds of living creatures. As the continent drifted northward, the climate changed to cold, the snow began to turn into long-term ice. But under the thickness of the ice, the soil itself still has microorganisms. They live at the expense of decaying ancient biomass and secrete methane. This gas has already accumulated several billion tons. But it is "preserved" by a powerful ice shield.
What will happen to the atmosphere of the planet if this gas gets into it? The consequences will be very sad for civilization. Not to mention the fact that with the complete liberation of Antarctica from ice, the level of the World Ocean will rise by 60 meters! And this is without taking into account the fact that actively melting now Greenland will add to the level of another 8 meters. But there are dozens and other powerful glaciers on the planet.