In a remarkable achievement for climate science, a team of European scientists has successfully extracted what is likely the world's oldest ice, dating back approximately 1.2 million years, from deep within Antarctica. This monumental endeavor, conducted under extreme conditions with temperatures plummeting to -35°C, resulted in the retrieval of a 2.8-kilometer-long ice core—an impressive length that surpasses the combined height of eight Eiffel Towers.
The extraction took place at a site known as Little Dome C, located on the Antarctic plateau at nearly 3,000 meters above sea level. Throughout four Antarctic summers, the team, led by the Italian Institute of Polar Sciences and comprising ten European nations, overcame significant logistical challenges. They transported drilling equipment, laboratories, and a temporary camp over 40 kilometers from the nearest research base while racing against teams from seven other nations to reach the ancient ice first.
Suspended within this ancient ice are air bubbles that hold the key to unlocking a critical chapter of our planet's climate history. Scientists are particularly interested in the period between 900,000 and 1.2 million years ago, a time when glacial cycles underwent significant disruption. This era has been linked to a near-extinction event for our ancestors, with some theories suggesting that the human population may have dwindled to as few as 1,000 individuals. Professor Carlo Barbante from Ca' Foscari University of Venice, who coordinated the research, emphasizes the significance of this discovery: "You have in your hands a piece of ice that is a million years old."
Ice cores serve as invaluable records of Earth's climatic past, encapsulating air bubbles and particles that reveal historical levels of greenhouse gas emissions and temperature variations. Previous studies, such as those involving the EPICA ice core, have established a connection between contemporary climate change and human activities, particularly the burning of fossil fuels. However, the current project, aptly named "Beyond EPICA: Oldest Ice," aims to extend our understanding of climate history by an additional 400,000 years.
The findings from this ancient ice core could elucidate the Mid-Pleistocene Transition, a pivotal period characterized by a shift in the length of glacial and interglacial cycles from 41,000 years to 100,000 years. The reasons behind this transition remain largely enigmatic, and researchers are eager to explore potential links between these climatic changes and the survival challenges faced by early humans.
As the core is meticulously prepared for analysis—cut into one-meter segments and transported at -50°C to various European research institutions, including the British Antarctic Survey in Cambridge—scientists are poised to embark on an unprecedented exploration of our planet's climatic history. Dr. Robert Mulvaney, an ice core scientist at the British Antarctic Survey, described the final days of drilling as "nail-biting," highlighting the thrill of achieving greater depth than initially anticipated based on radar data.
While the exact revelations from this ancient ice remain uncertain, the implications for our understanding of climate dynamics are profound. As Professor Joeri Rogelj from Imperial College London notes, "What they will find is anybody's guess, but it will undoubtedly enlarge our window on our planet's past." The ongoing analysis promises to shed light on one of the most critical periods in Earth's climate history, offering insights that may inform our understanding of future climate scenarios.
The successful extraction of this ancient ice core from Antarctica marks a significant milestone in climate research, one that not only enhances our understanding of past climate conditions but also provides vital context for the challenges that lie ahead in an era of rapid climate change.