Researchers have made a groundbreaking discovery using the DNA of the Turquet octopus (Pareledone turqueti) to unearth evidence of a probable collapse of the West Antarctic Ice Sheet (WAIS) during the last Ice Age, about 120,000 years ago. This finding is crucial as it parallels current global temperatures and supports the theory that the tipping point of the WAIS may be reached, even under the Paris Agreement’s target to limit warming to approximately 1.5-2 degrees Celsius.
Published in Science magazine, this multinational study is a collaborative effort by researchers from universities and research institutes in Australia, New Zealand, Finland, Portugal, Ireland, Germany, and the United Kingdom.
The research builds on a previous genetic study, where a more efficient population genomics approach was developed. This method was used to test various hypotheses about connections between octopus populations in Antarctica.
"Continuous genetic similarities between the current Turquet octopus populations in the Weddell Sea, Ross Sea, and Amundsen Sea are only possible with the disappearance of the WAIS. The disintegration of the ice sheet opened a marine passage, connecting these otherwise distant regions," explains Professor Phillip Watts from the University of Jyväskylä.
This study provides answers to the long-standing debate on whether the WAIS collapsed during the last Ice Age.
“The study is significant for predicting the impacts of climate change. During the last Ice Age, the average global surface temperature was about 1.5 degrees Celsius warmer than the pre-industrial era, and sea levels were about 5-10 meters higher than today,” states Watts. “As the WAIS is currently a major contributor to sea-level rise in Antarctica, its complete collapse could raise sea levels by about 3-5 meters.”
Partially funded by the Academy of Finland, this research not only sheds light on historical climate events but also offers critical data for forecasting future climate change impacts, especially in understanding the potential rise in global sea levels.