We have been hearing in the past decades the possible perils of a climate change and experts are persistently warning us of its side effects, but not many believe that something like that can happen to us. Well, it has happened in the far past and scientists have proven that with their latest discovery.
This discovery is an evidence of a dramatic climate change of our southernmost continent, West Antarctica. In this region were discovered fossil roots, spores, and pollen revealing that around 90 million years ago, there existed a thriving temperate rainforest.
During expedition researchers found a 90-million-year sediment core
In 2017, the expedition of the RV Polarstern examined the seafloor of Amundsen Sea. The researchers drilled deep into the ground and found a 90-million-year sediment core from beneath this sea. The soil specimen was taken 560 miles (900 km) from the South Pole, which was very much different from the one closer to the surface.
Scientists have before excavated the seafloor when they found a strange substance beneath a bed of sandstone assuming that there was “something old” according to the geologist Johann Klages from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research in Germany. However, this time they excavated a canister of black, dirt-like material, and suspecting that it is ancient there was a risk of turning to coal over time, and because of that they decided “ not to open [the canister] onboard.”
In order to analyze it they used a digital image of the X-ray scans which revealed networks of preserved roots throughout the entire soil layer.
The extracted sample was beyond ancient, it dated to the peak dinosaur era, and although the roots have started decomposing into coal, the scientists managed to detect that some of its parts were from plants that are relatives of today’s ferns and conifer trees. The sample contained fossilized plant roots and evidence of pollen and spores which are clear proof of the existence of an ancient rainforest.
The first sample of the cretaceous-period in such a southern location
“During the initial shipboard assessments, the unusual coloration of the sediment layer quickly caught our attention. It clearly differed from the layers above it.”
Professor Ulrich Salzmann, a paleoecologist at Northumbria University and co-author of the study, explained how excited they were about this discovery being able to find ”well-preserved diverse fossil pollen and other plant remains in sediment deposited some 90 million years ago, near the South Pole.”
Salzmann said that this sample shows how the coast looked back then: “the coast of West Antarctica was, back then, a dense temperate, swampy forest, similar to the forests found in New Zealand today.”
Tina van of Flierdt, a professor at the Departments of Earth Science and Engineering at Imperial College London, stated:
“The survival of this 90 million-year-old forest is remarkable but even more surprising is the world that it reveals. Even during months of darkness, swampy temperate rainforests were able to grow close to the South Pole, revealing an even warmer climate than we expected.”
Researchers believe the area where they found the sample has been several hundred kilometers closer to the south at the time of the forest.
Antarctica is a continent with four months of darkness, and many people cannot believe that there was any plant and animal life even in ancient times, but experts explained that it is possible. They have made a reconstruction of the climate of the ancient forest using the biological and geochemical data from the sample. These plants had thrived in the presence of dense vegetation in an area short of major ice sheets. Plus, the global CO2 levels must have been significantly higher in that era making the average temperature in the Antarctic about twelve degrees Celsius (54 degrees Fahrenheit).
Geoscientist Torsten Bickert from the University of Bremen in Germany explained that the global CO2 emissions in that time would have been about one thousand parts per million (ppm).
He added: “It took concentration levels of 1,120 to 1,680 ppm to reach the average temperatures back then in the Antarctic.”
These findings are of great value as they may reveal the possible effects of the global CO2 levels on the planet if they get higher, and there is also the importance of the cooling effects of the ice sheets.
Klages continued: “We need to look into these extreme climates that happened on the planet already because they show us what a greenhouse climate looks like.”
Although the team of scientists, including the co-author and AWI climate modeler Dr. Gerrit Lohmann tried many climate simulations, they were “unable to find a satisfactory answer” to the reason for the occurrence of this dramatic change in the climate.