Diving into the Deep Freeze: What Ancient Ice Can Tell Us About Climate Change

A team of scientists undertook a daring mission, drilling deep into Antarctica’s ice sheet to pull up the oldest ice sample known to man. This massive 1.2 million-year-old core is now undergoing analysis in Germany, with researchers hopeful that it could shine a light on our current climate woes.

Unlocking Secrets from the Ice

Drilling down a staggering 2,800 meters (almost 1.74 miles) has resulted in the retrieval of what could be the oldest continuous ice core ever. Scientists are eager to decipher its secrets, which may reveal important insights about Earth’s climatic past.

According to Maria Hörhold, a glaciologist with the Alfred Wegener Institute (AWI), ice cores serve as crucial archives of climatic history. “They tell us something about the climate history of the Earth,” she explains.

Analyzing Bubbles in Time

This ancient ice core is filled with tiny air bubbles that trap atmospheric gases, paving the way for scientists to analyze the concentration of greenhouse gases, such as CO2, over the last 1.2 million years. The ultimate goal? To better understand how climate change is impacted by the carbon cycle and global temperatures.

Cycling Through Time

Past ice cores have shown that the climate experienced alternating hot and cold periods approximately every 100,000 years. However, diving further back into history reveals cold spells happening more frequently, around every 40,000 years. Hörhold elaborates, “This is mainly driven, for example, by planetary features, like how the Earth is positioned towards the Sun. Yet, the reason we transitioned from a 40,000-year cycle about 1.5 million years ago to our current climate patterns is still poorly understood.”

Researchers believe that by extending the existing 800,000-year dataset, they might pave the way for enhanced predictions about how Earth’s climate will react to future spikes in greenhouse gas emissions, according to Liz Thomas from the British Antarctic Survey.

A Treasure Trove of Atmospheric Records

Thomas also emphasizes that no other location on the planet holds such a lengthy record of past atmospheric conditions as Antarctica does, calling it our “best hope” for illuminating the basic forces that drive changes in Earth’s climate.

CO2 Levels at Historic Highs

It’s already known that greenhouse gas concentrations were on the lower side during cooler Earth periods. Warmer phases saw an upsurge in these gases, leading to a situation where heat was trapped in the atmosphere. Hörhold highlights the intention behind studying these ice cores—”It’s all about understanding the interactions within our climate system.”

Yet, it’s worth noting that previous warm seasons experienced CO2 levels far below those we see today, which have skyrocketed primarily due to human-induced global warming from fossil fuel combustion.

Collaborative Efforts Across Europe

This landmark project is part of a pan-European initiative called Beyond EPICA – Oldest Ice, which aims to delve deep into Antarctica’s past. The ice core sample has been sliced into one-meter pieces for additional analysis at institutions like the AWI and the British Antarctic Survey in Cambridge.

What’s Next?

While researchers are eager to share their findings, Hörhold admits it may take at least a year to see the first results, with a longer wait expected for additional discoveries. Nevertheless, for scientists like Hörhold, the ice core recovery marks a thrilling opportunity to learn more about our planet.

“Having that ancient ice in our hands is incredibly special; it signifies an unprecedented record of Earth’s history,” she shares. “It’s an honor for us to manage its processing here.”

Edited by Jennifer Collins