A snapshot of the past has been found in the form of a bubble frozen in the Antarctic ice.
The bubble, which is providing scientists with a unique glimpse in to what the Earth’s climate was like over a million years ago, was discovered inside an ice core drilled from a region in Antarctica known as Allan Hills which is near the McMurdo research station.
Offering the oldest picture yet of our planet’s past atmosphere, the sample contains gases such as carbon dioxide and methane that were trapped and preserved in falling snow long ago.
An analysis of the discovery has revealed a strong connection between carbon dioxide levels and glacial cycles over the last one million years. It also suggests that there were no major swings in greenhouse gas levels during an interglacial period around 800,000 years ago.
“Gas bubbles are the gold standard for reconstructing climate,” said lead author John Higgins.
The data also indicated that carbon dioxide levels, which are around 400ppm today due to human activities, had never previously exceeded 300ppm at all during the entire last one million years.