The ocean floor of the South Pacific contains traces of ancient dust that may have changed Earth’s very climate, and new research suggests it came all the way from beneath ice-age glaciers of what is now Argentina. 

Whipped up by strong westerly winds some 20,000 years ago, these microscopic minerals would have circumnavigated nearly the entire globe before finally coming to rest in the middle latitudes of the Pacific.

Importantly, they carried a nutrient that could explain a period of global cooling. That ingredient was iron.

Iron is a vital nutrient for microscopic algae in our oceans, known as phytoplankton, and these creatures are in turn a fundamental part of Earth’s climate.

That’s because phytoplankton absorb carbon during photosynthesis, thereby storing atmospheric CO2 in our oceans and driving global cooling. They might even represent “the largest biological carbon sequestration mechanism on the planet“.