Oldest air on Earth hiding in Antarctic ice

A researcher from the University of Copenhagen examines an ice core from the West Antarctic Ice Sheet. (NASA/Lora Koenig)

Tiny puffs of air from 1.5 million years ago may be locked inside bubbles in the ice nearly two miles beneath Antarctica’s surface. That ancient air, if it exists, would be the oldest sample of Earth’s atmosphere ever recovered.

Geoscientists recently identified regions of the frozen continent that potentially preserved the not-so-fresh air. Getting a whiff of the Earth’s oldest breeze would allow an analysis of chemicals in the air at a crucial point from 1.2 million to 900,000 years ago, known as the  Mid-Pleistocene Transition.

“The Mid Pleistocene Transition is a most important and enigmatic time interval in the more recent climate history of our planet,” said lead author of the new study published in Climate of the Past Hubertus Fischer of the University of Bern, Switzerland, in a press release.

During the transition, the Earth went from extreme warmth and cooling cycles alternating  approximately every 41,000 years to having the cycles change only about every 100,000 years. Sediment samples drilled from the bottom of the ocean recorded the temperature differences, but scientists don’t know why the global thermostat cycles slowed.

Ice samples from other areas yielded 800,000-year-old air bubbles. Those samples showed a lockstep correlation between higher greenhouse gas levels and increased temperatures over thousands of years, according to research published in Nature.

Greenhouse gases, such as methane and carbon dioxide, may have been the culprits behind the Mid-Pleistocene Transition, as well. However, drills will need to pluck a 2.4 – 3.2 (1.5 – 2 mile)-kilometer-long ice core from the Antarctic ice to give scientists the 1.5 million-year-old sample they need.

“A deep drilling project in Antarctica could commence within the next three to five years,” Fischer said. “This time would also be needed to plan the drilling logistically and create the funding for such an exciting large-scale international research project, which would cost around 50 million Euros.”