Making wastewater less acidic could help the ocean capture more carbon

Reducing the acidity of the huge volumes of wastewater discharged into the oceans could be a relatively straightforward way to remove carbon dioxide from the atmosphere and slow climate change. But early tests have spurred controversy over potential environmental consequences.

Ming Li at the University of Maryland says about 100 trillion litres of wastewater are discharged into the oceans each year. Chemicals are often added to make it less acidic in order to meet environmental standards before it is discharged…