Dust in the Southern Ocean has influenced climate over millions of years

Researchers from the Universitat Autònoma de Barcelona (UAB) and the Swiss Federal Institute of Technology (ETH Zürich) have shown a close relation between contributions of dust to the southern ocean and intense periods of climate change during the Pleistocene.

The dust is formed by various Earth surface processes and provides micronutrients, especially iron, which is essential for marine organisms and it seems that this process increased during glacial periods suggesting iron fertilization could have increased ocean productivity, reducing CO₂ in the atmosphere during the last million years of glacial periods.

The study suggests the dust plays a key role in fertilizing algae in the Southern Ocean, which in turn absorb CO₂ and is stored on the sea floor. It is already understood that the Southern Ocean is an important carbon sink, but this research tells us about the intricate relationship between the oceans and the atmosphere.

Iron fertilization has already been considered as a geo-engineering solution to climate change, but doubt surrounding how ecosystems would react to this artificial process is unknown. Ocean circulations have changed over the last million years as well, which could make the process less effective.