Fifteen million years ago, the Earth’s climate entered into a period of slow, continuous cooling, and simultaneously the Antarctic ice sheet grew steadily larger.
Fifteen million years ago, the Earth’s climate entered into a period of slow, continuous cooling, and simultaneously the Antarctic ice sheet grew steadily larger. Finally, around 2.5 million years ago, Greenland became covered in ice, thrusting the Earth into its current bipolar ice age.
Geoscientists have been debating what brought about this global cooling for many years. Some argue that major mountain ranges such as the Andes, the Himalayas and the Alps started to form 15 million years ago, and that they accelerated erosion and the weathering of rocks. This theory posits that the formation of mountains drew more carbon dioxide (CO2) from the atmosphere than processes such as volcanic eruptions were giving off, causing temperatures to continuously decrease.
Constant weathering, increased reactivity
A team of researchers from ETH Zurich, Stanford University and the German Research Centre for Geosciences (GFZ) in Potsdam has now demonstrated that this hypothesis is not accurate enough. Their study was recently published in the journal Nature.
Read more at: ETH ZURICH
Soil formation in the Chilean coastal mountains. The soil is already heavily weathered, but granite blocks remain and can react chemically: The ‘reactivity’ of this soil is high. (Photo: F. von Blanckenburg, GFZ)