Spreading Rock Dust on Ground Could Absorb Carbon From Air, Study Says
A new way to fight climate change?
Spreading rock dust on farmland absorbs enough carbon dioxide from the atmosphere that it could remove roughly half of the amount of greenhouse gas currently produced in Europe, according to a recent study published in the journal Nature.
The new research, carried out by scientists at the University of Sheffield’s Leverhulme Centre for Climate Change Mitigation and the school’s Energy Institute, looked into a particular technique known as enhanced rock weathering, which involves spreading out finely crushed basalt, a natural volcanic rock, on farmlands to boost the soil’s ability to pull CO2 from the air.
The researchers noted that this might be the best near-term option of removing billions of tons of CO2 from the atmosphere to meet the Paris Agreement goals of keeping the global temperature rise below 2 degrees Celsius.
“Carbon dioxide drawdown strategies that can scale up and are compatible with existing land uses are urgently required to combat climate change, alongside deep and sustained emissions cuts,” the study’s lead author David Beerling said in a statement.
“Spreading rock dust on agricultural land is a straightforward, practical CO2 drawdown approach with the potential to boost soil health and food production.”
The study showed that China, the United States and India—the world’s biggest fossil fuel CO2 emitters—have the highest benefit of using rock dust on farmlands. Together, these three countries have the potential to remove about 1 billion tons of CO2 from the atmosphere.
The researchers noted that both Indonesia and Brazil, whose CO2 emissions are ten to twenty times lower than the U.S. and China, would also greatly benefit due to their expansive agricultural lands and climates that increase the efficiency of rock weathering.
The study suggested that meeting the demand for such rock dust could come from utilizing stockpiles of silicate rock dust left over from mining operations. Scientists have also called on governments to develop national inventories of these important resources.
“We have passed the safe level of greenhouse gases,” the study’s co-author James Hansen said in a statement.
“Cutting fossil fuel emissions is crucial, but we must also extract atmospheric CO2 with safe, secure and scalable carbon dioxide removal strategies to bend the global CO2 curve and limit future climate change.”
Ethen Kim Lieser is a Minneapolis-based Science and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek and Arirang TV. Follow or contact him on LinkedIn.
Image: Reuters