Antarctic Ice Sheet Has Irregular Heartbeat- Research Says It’s Not a Good Sign for Climate Change

Scientists have likened the growth and melting of ice sheets in Antarctica to that of a human heartbeat. The size variations in the Antarctic ice sheet over time have confirmed its unstable nature throughout history. Though initially thought to be a static feature of the South Pole, the rhythmic cycles of ice growth and its eventual melting have become inconsistent. Moreover, it may continue to topple if the current pace of greenhouse gas emissions continues. To indicate the delicate nature of the early ice ages, a new study published in the journal Nature Communications has retrieved climate records from about 20 million years ago suggesting that the Antarctic ice sheet has experienced sudden periods of melting.

The variations in rhythms remain a point of concern for scientists as they theorize that the rhythm, resembling a heartbeat, should remain consistent nevertheless. The researchers considered a time when the planet was warmer than today about 28 million years ago. At the time, the Antarctic ice sheet was the only one in existence, thus, extracting data from geological cores was beneficial in studying the dynamics of the ice sheet. The researchers examined microorganisms from these cores recovered from the northwest Atlantic Ocean conducted by the Integrated Ocean Drilling Program (IODP) in 2012. 

The state of the ocean some 28 million years ago, including environmental and chemical characteristics, is reflected in the microscopic organisms existing in the cores. The form of oxygen isotopes in the microorganism shells provides clarity on the measure of growth and shrinking of the ice sheet. “It may be a surprising thing to learn that we take the pulse of the Antarctic ice sheet by doing some simple chemistry on pinhead-sized fossil shells from the deep sea floor on the other side of the world,” said Professor Paul Wilson, principal investigator on the project at the University of Southampton. He expressed confidence in the geological records accumulated over tens of millions of years to gather knowledge about Earth science and further help understand the future of the planet in the long run. 

Essentially, the heartbeat-like rhythms of the ice sheet are influenced by the shape of the Earth’s orbit around the Sun over the course of time. In the case of a stable circular Earth orbit, the ice sheet maintains a stable state with reduced melting. Whereas, an irregular orbit will allow the planet to absorb varied amounts of heat depending upon the distance between the Earth and the sun. Simultaneously, there will be consequential melting of ice sheets as per the heat absorbed affecting the global climate. Wilson and his team created a benchmark climate record through the analysis of geological cores which shall be beneficial in devising climate models to determine the behavior of Earth’s climate change patterns. 

“Past climate changes rapidly ended some of the early Antarctic ice ages and caused large amounts of melt. ‘Rapidly’ is on geological time scales, not as rapid as we can expect to happen during modern climate change,” lead author Dr. Tim van Peer stated. He works at the University of Leicester School of Geography, Geology and the Environment. Hence, it is not difficult to estimate the impact of greenhouse emissions on the already unstable Antarctic ice sheets, which makes it almost impossible to predict how soon we may surpass crucial tipping points.