The Post

Welcome to the Antarctic jungle

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Antarctica was once a swampy forest with an average temperatur­e of 12C, scientists have concluded.

The study, published in the journal Nature, found that the continent had a much more temperate climate 90 million years ago – similar to that of parts of New Zealand today.

Scientists discovered the previous temperatur­e of the Antarctic by looking at soil samples from the mid-Cretaceous period (80-115 million years ago).

The team said analysis of preserved roots and other plant remains in the soil suggests the world at that time was warmer than previously thought.

They analysed an ice core extracted from the seabed near the Pine Island and Thwaites glaciers in west Antarctica. The team found well-preserved forest soil, including plant pollen, spores, a dense network of roots and the remains of flowering plants. It is not yet know what caused the climate change and ice sheets to form.

Professor Tina van de Flierdt, an Earth sciences expert from Imperial College London, and one of the study’s authors, said: ‘‘The preservati­on of this 90 millionyea­r-old forest is exceptiona­l, but even more surprising is the world it reveals. Even during months of darkness, swampy temperate rainforest­s grew close to the South Pole, revealing a warmer climate than expected.’’

Prof Ulrich Salzmann, a palaeoecol­ogist at Northumbri­a University, said: ‘‘The numerous plant remains indicate that 93 to 83 million years ago, the coast of west Antarctica was a swampy landscape in which temperate rainforest­s grew – similar to the forests on New Zealand’s South Island.’’ The findings also indicate carbon dioxide levels were higher than expected.

Professor Gerrit Lohmann, a German climate modeller, said: ‘‘The assumption was that the global carbon dioxide concentrat­ion was 1000 ppm (parts per million). But in our model-based experiment­s, it took concentrat­ion levels of 1120 to 1680 ppm to reach the average temperatur­es then in the Antarctic.’’

 ?? JAMES MCKAY ?? Ninety million years ago, parts of Antarctica had a climate similar to that in regions of the South Island today.
JAMES MCKAY Ninety million years ago, parts of Antarctica had a climate similar to that in regions of the South Island today.

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