In 2023, Antarctic sea ice declined to historically low levels, prompting researchers to use CMIP6 climate models to assess the event’s rarity and its connection to climate change. The study found that without climate change, such a drastic reduction would be extremely rare, but current climate conditions made it more probable.
Using a large climate dataset called CMIP6, BAS researchers investigated this unprecedented sea ice loss. They analyzed data from 18 different climate models to understand the probability of such a significant reduction in sea ice and its connection to climate change. According to the models, the record-breaking minimum sea ice extent would be a one-in-a-2000-year event without climate change. This tells us that the event was very extreme – anything less than one-in-100 is considered exceptionally unlikely.”
Satellite records of Antarctic sea ice began in late 1978 and between then and 2015, Antarctic sea ice extent increased slightly and steadily. In 2017, Antarctic sea ice reached a record low, and has been followed by several years of relatively low sea ice extent.