When we think of the South Pole, we imagine a freezing continent, virtually void of life. However, this has not always been the case and it was once home to a tropical rainforest, research has revealed. In 2017, researchers drilled 2,000 metres beneath the surface of the South Pole to reveal fossil traces of a temperate rainforest which thrived there 90 million years ago.
The team from the UK and Germany discovered forest soil from the Cretaceous period in the seabed near the South Pole.
The samples were almost pristinely preserved in sediment core thanks to the thick layer of ice which has protected it from the elements since the time of the dinosaurs.
Analysis revealed the rainforests in Antarctica, which is evident by the discovered roots, pollen and spores, were of a similar forest to those found in the likes of New Zealand today, according to the research published in the journal Nature.
Co-author Professor Ulrich Salzmann, a palaeoecologist at Northumbria University, said: “It was particular fascinating to see the well-preserved diverse fossil pollen and other plant remains in a sediment deposited some 90 million years ago, near the South Pole.
“The numerous plant remains indicate that the coast of West Antarctica was, back then, a dense temperate, swampy forest, similar to the forests found in New Zealand today.”
Back then, summer temperatures averaged 19 degrees Celsius and water temperatures in rivers and swamps reached up to 20C, despite the four month night.
Scientists put the warmer temperatures in the South Pole, which was 500 miles away 90 million years ago thanks to continental drift, down to the build up of greenhouse gasses during the cretaceous period, which lasted from 140 million to 66 million years ago.
Co-author, climate modeller Professor Gerrit Lohmann, from Germany’s Alfred Wegener Institute said: “Before our study, the general assumption was that the global carbon dioxide concentration in the Cretaceous was roughly 1000 ppm.
“But in our model-based experiments, it took concentration levels of 1120 to 1680 ppm to reach the average temperatures back then in the Antarctic.”
Due to the warmth, sea levels were a staggering 170 metres higher 90 million years ago than they are today.
And the team believes the study should serve as evidence as to how extreme an effect carbon dioxide can have on the planet.
Dr Johann Klages of the Alfred Wegener Institute in Germany and a co-author of the research, said: “We didn’t know that this Cretaceous greenhouse climate was that extreme.
Antarctica shock: NASA’s before and after pics show horror of ice melt
How top-secret wartime mission led to first British Antarctic Survey
Antarctic turns RED as ocean hit by bizarre ‘watermelon snow’
“It shows us what carbon dioxide is able to do.”
Dr James Bendle, an expert in organic geochemistry from the University of Birmingham, said: “Ultimately, if we have an atmosphere of more than 1,000 parts per million of carbon dioxide, we are committing ourselves to a future planet that has little to no ice, and ultimately an Antarctic continent that would be vegetated and wouldn’t have an ice cover.”
The research also showed that there were no ice sheets back then, and the next stage of the study will to analyse how the South Pole became as cold as it is today.
Source: Read Full Article