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 Sea Field Base, each of the last four summers

has been devoted to drilling.

Federico Scato is a researcher on the project.

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.

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 an 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.

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.

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. The big picture this feeds into is climate and energy.

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