A swath of Antarctica‘s sea ice larger than four times the size of France has melted since 2014, AFP reported Tuesday.

The rapid decline, revealed in a study of satellite data published by the Proceedings of the National Academy of Sciences, marks a stunning reversal for the South Pole: Between 1979 and 2014, its sea ice was actually expanding. Then, it lost 2.1 million square kilometers (approximately 810,815 square miles) in three years, falling from 12.8 million square kilometers (approximately 4.9 million square miles) to 10.7 million square kilometers (approximately 4.1 million square miles).

Read more: Weforum