olivine dust could fight climate change
Dusting the soils along the equatorial portion of earth with the common, semiprecious gem olivine may sponge carbon dioxide from the atmosphere and slow the pace of climate change.
When water, CO2 and silica-containing rocks mix, the resulting chemical reactions produce minerals that contain carbon, known as carbonates.
When water drains to the sea, carbonates are carried along and buried in its depths, along with the carbon they carry. And since olivine, a silicate, is among the world’s most common minerals, some researchers have wondered whether it may be put to carbon-sucking use.
“We know this is already happening. The question is, how much can we dissolve without disturbing the natural environment?” said geochemist Jens Hartmann of Germany’s University of Hamburg, lead author of the study published Nov. 9 in the Proceedings of the National Academy of Sciences.
Hartmann’s team calculated how much carbon might be absorbed by olivine mined from equatorial deposits, ground to a fine powder and scattered across the Amazon and Congo river basins.
According to their estimates, olivine powdering could, if done every year over most of those regions, theoretically lower atmospheric CO2 levels by 80 to 150 parts per million by the century’s end.
Barring radical changes in fossil fuel consumption, global CO2 levels are expected to reach about 700 ppm by that time; about 350 ppm is considered safe, or at least non-catastrophic. Olivine alone wouldn’t keep CO2 under control, but Hartmann said it could be “one of dozens of geoengineering methods that can contribute to CO2 management.”
Actual logistics of a project this size would require cooperation from millions of individual farmers and landowners, ultimately covering only portions of equatorial soils. Additionally, small-scale tests need to be designed to give a better understanding of the dynamics and consequences.
Posted | Tags: environment