Floating Antarctic ice plummets from record high to record lows in three years, baffling scientists
- Nasa study of satellite data shows levels have dropped precipitously
- Amount of ice lost between 2014 and 2017 covered area larger than Mexico
The amount of ice circling Antarctica is suddenly plunging from a record high to record lows, baffling scientists.
Floating ice off the southern continent steadily increased from 1979 and hit a record high in 2014. But three years later, the annual average extent of Antarctic sea ice hit its lowest mark, wiping out 3½ decades of gains – and then some, a Nasa study of satellite data shows.
In recent years, “things have been crazy,” said Mark Serreze, director of the National Snow and Ice Data Centre. In an email, he called the plummeting ice levels “a white-knuckle ride”.
Serreze and other outside experts said they do not know if this is a natural blip that will go away or more long-term global warming that is finally catching up with the South Pole. Antarctica has not showed as much consistent warming as its northern Arctic cousin.
“But the fact that a change this big can happen in such a short time should be viewed as an indication that the Earth has the potential for significant and rapid change,” University of Colorado ice scientist Waleed Abdalati said in an email.
At the polar regions, ice levels grow during the winter and shrink in the summer. Around Antarctica, sea ice averaged 12.8 million square kilometres (4.9 million square miles) in 2014. By 2017, it was a record low of 10.7 million square kilometres (4.1 million square miles), according to the study in Monday’s Proceedings of the National Academy of Sciences.