Crushed rocks outpace giant fans in race to remove CO2 from air

Projects that spread rock dust on farms are removing more carbon dioxide from the atmosphere than competing technologies – but CO2 removal efforts remain far short of what is needed to avoid dangerous levels of global warming.

Known as enhanced rock weathering, the method involves spreading crushed volcanic rocks over fields to accelerate the natural weathering process by which CO2 in the atmosphere is converted to stable mineral form. Spurred by its relative simplicity – and new evidence that the rock dust can improve crop yields as well as sequester carbon – this…