56-million-year-old sediments reveal a troubling climate scenario

By analyzing sediments from the time of global warming 56 million years ago, a team from the University of Geneva has uncovered a disturbing scenario: the increasing intensity of precipitation could Ocean uninhabitable for some creatures to make. The University of Geneva writes this in a statement on Thursday.

56 million years ago, Earth experienced one of the strongest and fastest climate warmings in its history: the Paleocene/Eocene Maximum Temperature (PETM). Within 5,000 years, global temperatures will have risen by five to eight degrees. The warming lasted about 200,000 years and led to the extinction of countless creatures in the sea and on land.

The cause of this global warming is a strong increase in the greenhouse gases CO₂ and methane supposed. The origin of these processes is still disputed. The impact of a meteorite or intense volcanic activity in the depths of the North Atlantic could be responsible.

Because of the many Similarities between the PETM and current warming the geological remains of this period were carefully examined by scientists. To do this, they analyzed a 543 meter long drill core taken from a depth of more than 8 kilometers in the Gulf of Mexico. At the core is a 180 meter thick layer of PETM sediment the world’s most complete geological “archive” of this period.

The researchers read from the drill core that there was no increase in annual precipitation during this period, but rather an increase in the seasonal influences and intensity of the precipitation. “As a result, the mobility of the river channels – i.e. the deepest parts of a river – was intensified, transporting large amounts of river clay, which was deposited in the adjacent alluvial plains, to the depths of the ocean,” said environmental scientist Lucas Vimpere in the university’s statement.

This has led to increased ocean turbidity, which is harmful to marine life, especially coral. This scenario could repeat itself todaythe researchers said.

(sda)