While burning coal today causes Earth to overheat, about 300 million years ago the formation of that same coal brought our planet close to global glaciation. For the first time, scientists show the massive effect in a study published in the renowned Proceedings of the US Academy of Sciences. When trees in vast forests died during a time called the Carboniferous and the Permian, the carbon dioxide (CO2) they took up from the atmosphere while growing got buried; the plants’ debris over time formed most of the coal that today is used as fossil fuel. Consequently, the CO2 concentration in the atmosphere sank drastically and Earth cooled down to a degree it narrowly escaped what scientists call a ‘snowball state’.
While burning coal today causes Earth to overheat, about 300 million years ago the formation of that same coal brought our planet close to global glaciation. For the first time, scientists show the massive effect in a study published in the renowned Proceedings of the US Academy of Sciences. When trees in vast forests died during a time called the Carboniferous and the Permian, the carbon dioxide (CO2) they took up from the atmosphere while growing got buried; the plants’ debris over time formed most of the coal that today is used as fossil fuel. Consequently, the CO2 concentration in the atmosphere sank drastically and Earth cooled down to a degree it narrowly escaped what scientists call a ‘snowball state’.
“It is quite an irony that forming the coal that today is a major factor for dangerous global warming once almost lead to global glaciation,” says author Georg Feulner from the Potsdam Institute for Climate Impact Research. “However, this illustrates the enormous dimension of the coal issue. The amount of CO2stored in Earth’s coal reserves was once big enough to push our climate out of balance. When released by burning the coal, the CO2 is again destabilizing the Earth system.”
Read more at Potsdam Institute for Climate Impact Research (PIK)
Image: Annual mean temperature map for latest-Carboniferous temperatures for 150 ppm of CO2 and a cold orbital configuration, with reconstructed contours of continents. Fig. 2 of Feulner et al (cutout) (Image via PIK)
