Testing the waters: can pumping chemicals into the ocean help stop global heating?

To some it was a reckless experiment but scientists hope the dispersal of 65,000 litres of sodium hydroxide into the Gulf of Maine could ease the climate crisis

For four days last August, a thick slick of maroon bruised the waters of the Gulf of Maine. The scene, not unlike a toxic red tide, was the result of 65,000 litres of an alkaline chemical, tagged with a red dye, that had been deliberately pumped by scientists into the ocean.

Though it sounds perverse, the event was part of a scientific experiment that could advance a technology to combat both global heating and ocean acidification. Ocean alkalinity enhancement (OAE), as the approach is called, acts like natural weathering, but on human - rather than geological - timescales.