A drop in the ocean: does experimental technology hold the key to saving the world’s seas?

The acidity of global seawater is rising at an alarming rate. Adding huge amounts of alkaline materials to ocean waters can restore the pH balance, some companies say. Illustration: Mona Eing & Michael Meissner/The Guardian

In October 2024, a US company called Ebb Carbon announced the world’s largest marine carbon removal deal to date, signing a multimillion-dollar agreement with Microsoft to try to help fix a very real problem in the world’s seas: ocean acidification.

Ebb plans to use a method called electrochemical ocean alkalinity enhancement (OAE) to mimic the natural process of ocean alkalisation – in other words, it wants to add huge amounts of alkaline materials to ocean waters that scientists now know are acidifying at an alarming rate.