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“In order to understand how the ice might behave in the future, one of the crucial pieces of information is to understand how it behaved in past times of warmer conditions,” says Julia Wellner, a glacial sedimentologist at the University of Houston.

As global temperatures rise, so does the threat of glaciers melting into the sea; Antarctica alone contains enough ice to raise global sea levels by about four metres (13ft).

By drilling deep into ice and rock, scientists are uncovering the past lives of the ice, which are hidden within microscopic fossils made of glass – no wider than the width of a human hair – called diatoms.

But what exactly are diatoms? Click play on the video above, and learn more.

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