For more than 20 years, Louise Sime has worked at the British Antarctic Survey specialising in polar climate dynamics. She uses ice cores to reconstruct past conditions and predict future changes. She now leads several international Earth modelling projects.
Why are the Arctic and Antarctic regions important for the rest of the world?
They are one of the pillars of global climate stability, a giant store of frozen water, an essential “biotic pump” that helps to store carbon, and an albedo shield that reflects much of the sun’s light and heat back out to space.
When and why did scientists become concerned about tipping points in Antarctica?
It has become a major talking point in the past five to 10 years, though the possibility has been known for much longer. Up until 2016, the sea ice in Antarctica seemed relatively stable. Then everything started to change. At first, the decline was mostly in line with climate models. But suddenly, in 2023, there was an enormous drop. About 2.5 million sq km of Antarctic sea ice went missing relative to the average before 2023. The anomaly was of such a magnitude that it’s quite hard for scientists to know what to make of it. It has been described as a five sigma event.
