Pristine sub-Antarctic Heard Island, an Australian external territory located approximately 4,100 kilometers southwest of Perth and 1,700 kilometers north of Antarctica, is experiencing dramatic glacier loss due to climate change. New research from Monash University has revealed that almost a quarter (23.1 %) of the island's glaciers have melted, representing a loss of approximately 64 square kilometres of iceland since 1947.

Heard Island, which has been covered in ice for 61 % and dominated by the active volcano Big Ben, which rises over 2,800 meters, is considered one of the world's last intact ecosystems and is a UNESCO World Heritage Site. Its remote location in the Southern Ocean makes it a key part of the global climate system and an important indicator of the health of the planet.

Dr. Levan Tielidze, a researcher at the Securing Antarctica's Environmental Future (SAEF) centre at Monash University, stressed that studying this remote environment can tell us a lot about how the rest of our planet is doing in the face of climate change. "These findings are a harbinger of changes in our global climate system,” said Dr. Tielidze. He added that although Heard Island is almost the most remote place on Earth, it is still suffering from the profound effects of climate warming, which is “almost certainly caused by increasing greenhouse gas emissions in the 20th and 21st centuries.”

To study the island, which has been underexplored due to its difficult terrain, Monash researchers used topographic maps from 1947 and satellite imagery from historical and contemporary Earth observation platforms. The resulting glacier inventory catalogues 29 glaciers and tracks their contours in 1947, 1988 and 2019, documenting key morphological features.

Findings, published in the journal The Cryosphere, have forced scientists to repeatedly call for decisive climate action. The team hopes to build on this work during a planned visit to the island by the Australian Antarctic Program to investigate how glacier retreat is threatening mountain biodiversity. Professor Andrew Mackintosh, head of the Monash School of Earth, Atmosphere and Environment, said computer models would be used to predict how glaciers would respond to global warming. Two possible futures would be explored: one in which strong action is taken to reduce greenhouse gas emissions, and one in which little is done. The future of biodiversity on the island depends on human behaviour and the path we choose in terms of greenhouse gas emissions. JRi