evidence: Sea-ice extent around the frozen continent was measured at 1.99 million square kilometres, with scientists suggesting a ‘regime shift’ could be underway. [...] On September 10, 2023, Antarctica’s maximum winter sea-ice extent dipped to a new record low of 16.96 million square kilometres. Above graph: Daily observations of overall Antarctic sea-ice extent [SIE] reveal 2023 (dark green line) as the lowest winter extent since records began in 1979. The light green line shows 2014 data, with the record high (winter) Antarctic SIE of 20.12 million square kilometres. The dark green line shows the 2023 data, with the current record low summer and winter Antarctic SIE. The black line shows the long-term mean SIE based on 1981–2010, with grey traces showing the remaining observations for each year since 1979. Credit A. Steketee and P. Heil using data from NSIDC (data from 11 February 2024).