Scientists discovered that Antarctica’s ice sheet became dramatically more climate-sensitive after crossing a critical threshold one million years ago.
A new study suggests that Antarctica’s massive ice sheet underwent a major change about one million years ago, becoming far more responsive to shifts in Earth’s climate.
The research, led by scientists at the IBS Center for Climate Physics (ICCP) at Pusan National University in South Korea, offers fresh insight into how large ice sheets react to long-term climate changes and may help improve projections of future sea level rise.
Today, Antarctica contains the largest reservoir of ice on the planet and plays a crucial role in regulating global sea levels. Around one million years ago, however, Earth’s climate experienced a dramatic transformation. During this period, known as the Mid-Pleistocene Transition, ice ages became longer, colder, and more intense than before.
Although scientists have long recognized this shift, understanding exactly how the Antarctic ice sheet responded has been difficult because realistic records of ancient temperature and precipitation conditions have been limited.
To address that challenge, the research team relied on an advanced paleoclimate simulation recently developed at the ICCP. The model successfully recreates global climate conditions spanning the past 3 million years.
The scientists then used temperature and precipitation data from that simulation to drive the Penn State University ice-sheet–ice-shelf model. This sophisticated model tracks changes in ice sheet thickness, flow, and temperature across Antarctica and the Northern Hemisphere. It also simulates the behavior of floating ice shelves, including those in the Ross and Weddell Seas.
Running on one of South Korea’s fastest supercomputers dedicated to basic science research, the model produced a physically consistent picture of how the world’s major ice sheets evolved as conditions changed through time.
