Antarctica, ice melting towards a critical point

The temperature map of the last 45 million years said it

by Lorenzo Ciotti
Antarctica, ice melting towards a critical point

A study by Victoria University of Wellington, New Zealand, and the British University of Birmingham, and published in the journal Nature Geoscience, said Antarctica is near a tipping point according to the Southern Ocean temperature change map covering the past 45 million of years.

The researchers examined samples collected during ocean drilling projects, looking for fossils of small lipid molecules produced by organisms similar to bacteria and made up of a single cell, the archaea. These organisms, in fact, change the composition of their outer membrane in response to changes in sea temperature: by studying these changes, therefore, it is possible to reconstruct the temperature of the water at the time of their death.

By studying these changes it is therefore possible to deduce what the temperature of the water was at the time of their death. The authors of the study then combined this methodology, widely used by paleoclimatologists, with automatic learning techniques, taking it to a higher level and obtaining a complete and precise map of a large part of the Cenozoic Era.

Antarctica, ice melting towards a critical point

James Bendle of the University of Birmingham, explained: "The log we produced offers a much more comprehensive overview of the fluctuations in Antarctic temperatures, and how these relate to changes in the ice quantity and topography of Antarctica.

This allows us to open the way to even more accurate predictions for events that may occur in the future. Our study of the Earth's past is one of the clearest indications that current CO2 levels will cause large ice loss in the outermost parts of the Antarctic continent and a consequent global sea level rise that will occur over the next decades and centuries.

" The data indicate that further melting of the ice could cause a catastrophic rise in sea level, which could rise by as much as 50 meters. The map also confirms recent predictions on the planet's 16 monitored points, which include the disappearance of the Antarctic ice shelves among the five events closest to the point of no return due to global warming following the climate crisis.