Archives par mot-clé : D/O cycles

Climatologist: Are We Really In An Unprecedented Time Of Warming?

by M. Wilelicki, Nov 7, 2023 in ClimateChangeDispatch

Dansgaard-Oeschger (D-O) events are one of the most striking discoveries in earth science related to past climate.

They are named after the two climatologists, Willi Dansgaard and Hans Oeschger, who were instrumental in their identification.

These events are rapid climate fluctuations that occurred frequently during the last glacial period, illustrating a planet capable of swift and dramatic temperature shifts. [emphasis, links added]

The discovery of D-O events can be traced back to the ice core drilling projects in Greenland in the late 20th century.

Analysis of the isotopic composition of ice cores, particularly the ratio of oxygen isotopes 18O and 16O, revealed evidence of abrupt climatic changes.

These isotopes served as proxies for past temperatures, with higher ratios indicating warmer periods.

The meticulous work of Dansgaard and Oeschger, along with their colleagues, in the 1980s led to the recognition that the Earth’s climate has not always changed at a steady pace but has seen dramatic swings, especially during the last glacial period around 115,000 to 11,700 years ago.