The DNA of Turquet’s octopuses may hold the key to understanding changes in Antarctica’s past. A recent study published in the journal Science reveals that these small, seafloor-dwelling creatures were able to navigate a melted West Antarctic Ice Sheet approximately 125,000 years ago. This discovery is significant as it suggests that the last time Earth experienced similar temperatures to today’s exceptional heat, the ice sheet may have also collapsed.
The findings are concerning as they provide strong evidence that the West Antarctic Ice Sheet becomes unstable and could collapse when global temperatures warm by more than 1.5C above preindustrial levels. With current global temperatures already around 1.2 degrees Celsius above the preindustrial average, scientists worry that sea levels could ultimately reach the levels seen during the Last Interglacial, which occurred approximately 129,000 to 116,000 years ago.
The study, led by researcher Sally Lau and co-authored by Tim Naish and others, utilized genetic material from nearly 100 octopuses to analyze their historical voyages around Antarctica. Through genetic sequencing technology, the team found that the octopuses traveled in direct routes between different seas after the western ice sheet fully melted, indicating that the collapse of the ice sheet allowed them to migrate and interbreed with each other.
Notably, the results are timely as researchers, including paleoclimate researcher Tina van de Flierdt and her colleagues, are currently in Antarctica conducting the SWAIS2C project, which involves drilling to find old sediment deposited under the ice. This project aims to study the vulnerability of the West Antarctic ice sheet in the event of up to 2 degrees Celsius of warming.
While the study of the octopuses may not have a perfect analogue to the current situation, van de Flierdt believes that the geological past is the best bet to learn about how the planet might react to unprecedented greenhouse gas emissions. The findings from the study have raised alarms about the potential collapse of the West Antarctic Ice Sheet and its implications for global sea levels, reinforcing the urgent need for action to mitigate climate change.