Can Oceans Combat Climate Change By Dissolving CO2?

ACS Climate Science Toolkit | Narratives

Many people like the tingly sensation on their tongue when they drink Perrier or other water containing dissolved carbon dioxide. The tingly sensation is caused by the acidic solution produced when carbon dioxide dissolves in water. Increasing amounts of carbon dioxide are dissolving in the oceans and making them more acidic.

Ocean acidification is sure to affect the many living things that grow in the ocean, but we don’t know what the effects will be. Some species may thrive while others die, as has happened in the very distant past when massive extinctions of some ocean life and expansion of others occurred when oceans acidified.

A vast number of single-cell, photosynthesizing organisms, like the one shown in the sidebar, live in the top layer of the ocean. These are the lowest level of the ocean food web and are the source of essentially all the food eaten by other ocean creatures. Most of these organisms make outer walls of calcium carbonate—the same material that makes eggshells hard. Ocean acidification changes the ratios of carbonate-containing substances in the ocean. The changes could possibly make it easier or harder for these microorganisms to build their outer walls. We don’t know, but their survival has consequences for all the other creatures that depend on them for food, including human populations whose diet contains a lot of seafood.

Dissolving large amounts of carbon dioxide in the oceans is an unplanned experiment whose effects will change the Earth in unknown ways.

coccolithophore micrograph copy
Electron micrograph of a single-celled marine phytoplankton.
Source: Wikimedia Commons
Credit: Alison R. Taylor (University of North Carolina, Wilmington Microscopy Facility