❄️ The dust of the past is found in Greenland

Greenland ice cores show that, during the last glacial period, between 130,000 and 10,000 years ago, the amounts of mineral dust deposition were up to twenty times higher than today and varied very rapidly during abrupt climate changes.

Using advanced climate simulations with the HadGEM-ES Earth system model, a team of scientists shows that the variations in dust recorded in Greenland result from distinct mechanisms depending on the time scale considered.


On a glacial-interglacial scale, the overall increase in dust comes mostly from Asia, this dominance being linked to the expansion of arid zones and sparser vegetation. On the other hand, during abrupt climate events that occurred during glacial ages (periods ranging from fifty to several hundred years), the model reveals a major role for regions surrounding the Atlantic, particularly North Africa.

These cold periods cause a southward shift of tropical rain belts and a strengthening of atmospheric circulation, which reduces the removal of dust by precipitation and promotes its transport to high latitudes, as far as Greenland. This mechanism better explains the observed synchronization between dust variations in Europe (loess), the Atlantic, and Greenland, as well as some recent geochemical signatures.


These results challenge the interpretation that dust deposited in Greenland comes exclusively from Asian deserts, and they highlight a strong sensitivity of dust transport to rapid climate changes. They also open new perspectives on the potential role of dust in amplifying abrupt climate changes.

This study complements recent findings concerning the provenance of European wind-blown sediments from the Last Glacial Maximum and opens new perspectives on the potential role of dust in amplifying abrupt climate changes.