Australian valley a ‘natural laboratory’ to test carbon sequestration theory
Geoscientists at the University of Sydney have discovered a natural laboratory to test claims that the carbon captured during the erosion and weathering of common rocks could be a viable mitigation strategy against global warming.
That laboratory is the Tweed River valley in north-eastern New South Wales.
“When common rocks, known as olivine, chemically break down, they absorb carbon dioxide to form carbonates that can then be washed into the oceans,” said lead author of the study, Kyle Manley, a student at the University of Irvine in California, who started the research while studying at Sydney.
“In that way, river valleys like the Tweed can act as carbon sinks.”
The carbonates formed in this process later become the shells of marine animals and corals. Over millions of years, these remnants can form huge undersea carbonate structures. Occasionally they are pushed above sea level, such as the White Cliffs of Dover in England.
In order to combat global warming, some have proposed olivine weathering and its carbon capture could be harnessed to absorb millions of tonnes of carbon dioxide from the atmosphere.
“But those ideas haven’t really been tested at scale,” said Mr Manley, who started the study while on undergraduate exchange at the School of Geosciences at the University of Sydney, completing it at the University of Colorado, Boulder.
Research now published in the journal Frontiers in Earth Sciences, will allow scientists to test these claims in the Tweed catchment area, a 1326 square kilometre region, and in other regions that act as carbon sinks.
Co-author Dr. Tristan Salles from the School of Geosciences at the University of Sydney said: “We ran seven scenarios up to 2100 and 2500 to see