What an ancient ice core from Antarctica can tell us about our climate’s past and future

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• John Yang:

  Finally tonight, scientists say they've tapped into an extraordinary archive of the Earth's climate in the ice deep beneath Antarctica. They hope it'll help them understand both how climate changed in the past and how it's changing now and how it may change in the future.

  At a site in Eastern Antarctica known as Little Dome C Field Base. Each of the last four summers has been devoted to drilling.

  Federico Scoto is a researcher on the project.

• Federico Scoto, Researcher, Beyond EPICA:

  Working here, as you can imagine, is not easy. We work every day in extreme conditions. The warmest temperature was never higher than minus 14 or minus 16 degrees Fahrenheit.

• John Yang:

  Earlier this month, their efforts produced the results the international team of scientists had hoped for. From bedrock 1.7 miles deep, they extracted a time capsule roughly 1.2 million years old. The ice column is the length of six Empire State buildings. It represents ancient record of the Earth's climate and the story of a once warm Antarctica before it morphed into a snowy desert.

  Carlo Barbante coordinates the drilling project.

• Carlo Barbante, Coordinator, Beyond EPICA:

  We will now be able to assess when the glaciation of Antarctica started. We will understand when Antarctica was completely covered by ice. There is also another important aspect. Between the ice and the soil, there is an area containing sediment and microorganisms, viruses, bacteria, that can tell us a lot about how life developed in those faraway times.

• John Yang:

  In this faraway land, the same team of 16 researchers and support personnel had previously drilled an ice core dating back about 800,000 years. That ice, and the air bubbles inside it told scientists that greenhouse gas concentrations over that period, even at the warmest times, never exceeded the level seen since the dawn of the industrial age.

• Richard Alley, Climate Scientist:

  The big picture this feeds into is climate and energy.

• John Yang:

  Climate scientist Richard Alley was recently awarded the National Medal of Science for his career studying ice sheets. He wasn't involved in this project and says this new sample is more than just a history lesson.

• Richard Alley:

  The models that simulate the climate, as we make decisions about the energy system, we want them to be as good as possible. And by checking them against the ice core records, we can see what they do well, what we maybe need to improve a little bit, so we can make sure that the knowledge that goes to the policymakers and the public is as good as possible. It's already really, really good, but this will help make it better.