Key to speeding up carbon sequestration discovered

Scientists at Caltech and USC have discovered a way to speed up the slow part of the chemical reaction that ultimately helps the earth to safely lock away, or sequester, carbon dioxide into the ocean. Simply adding a common enzyme to the mix, the researchers have found, can make that rate-limiting part of the process go 500 times faster.

Calcite is a mineral made of calcium, carbon, and oxygen that is more commonly known as the sedimentary precursor to limestone and marble. In the ocean, calcite is a sediment formed from the shells of organisms, like plankton, that have died and sunk to the seafloor. Calcium carbonate is also the material that makes up coral reefs—the exoskeleton of the coral polyp.

As atmospheric carbon dioxide levels have risen past 400 parts per million—a symbolic benchmark for climate scientists confirming that the effects of the greenhouse gas in the atmosphere will be felt for generations to come—the surface oceans have absorbed more and more of that carbon dioxide. This is part of a natural buffering process—the oceans act as a major reservoir of carbon dioxide. At the present time, they hold roughly 50 times as much of the greenhouse gas as the atmosphere.

Armed with this knowledge, the team added the enzyme carbonic anhydrase—which helps maintain the pH balance of blood in humans and other animals—and were able to speed up the reaction by orders of magnitude.

Read more at Phys.org