World’s Biggest Iceberg Breaking Apart Amid Climate Change

Russian polar researchers have sounded the alarm after A23a, the world’s largest iceberg, lost a massive portion of its structure this year.

According to the Polar Research Institute, the iceberg has already shed about 36% of its area in 2025, with three huge fragments – ranging from 60 to 300 square kilometers – breaking away during the Antarctic winter months.

At the start of June, A23a measured around 2,730 square kilometers, roughly the size of Moscow. Today, its surface has shrunk to 1,750 square kilometers, comparable to the area of St. Petersburg.

A23a’s history stretches back to 1986, when it calved from the Filchner Ice Shelf and remained grounded in the shallow waters of the Weddell Sea for over 30 years. But in November 2023, it began drifting again into open waters, and by 2024 was moving along the Antarctic Peninsula toward the Scotia Sea.

Scientists warn that the continued disintegration of A23a highlights the accelerating impact of climate change on Antarctica’s fragile ice systems.