The amount of ice floating around Antarctica has rapidly plunged to record lows, according to new research.
It reached record highs in 2014 but within three years dropped to a new low point, losing an area of ice bigger than the size of Mexico.
Around Antarctica, sea ice averaged 4.9 million square miles in 2014 but by 2017, it was a record low of 4.1 million square miles, according to the study in Proceedings of the National Academy of Sciences.
Study author Claire Parkinson, a Nasa climate scientist, said losing that much in three years "is pretty incredible" and faster than anything scientists have seen before.
Antarctic sea ice increased slightly last year though was still the second lowest since 1979.
Despite ice growing at this time of year in Antarctica, levels in May and June were the lowest on record, according to the ice data centre.
In recent years "things have been crazy" said Mark Serreze, director of the National Snow and Ice Data Centre, and called the plummeting ice levels "a white-knuckle ride".
Mr Serreze and other experts said they do not know if this is a natural blip or if it was caused by long-term global warming catching up with the South Pole.
Additional reporting by agencies.
