Why ocean acidification could make some geoengineering schemes irrelevant - Resilience
The idea of runaway ocean acidification has now joined the idea of runaway global warming as a threat so large that it stands almost co-equal in its danger.
Part of the problem with ocean acidification is that
geoengineering schemes for lowering Earth’s temperature by reducing the sunlight that reaches the Earth’s surface won’t affect ocean acidification. And
recent research from the Massachusetts Institute of Technologysuggests that there is a tipping point in acidification beyond which the process becomes self-reinforcing and could lead to a mass extinction.
But those geoengineering schemes which block a portion of sunlight do nothing to prevent the ongoing acidification of the oceans. This occurs as more and more carbon dioxide dissolves in ocean waters. The dissolved carbon dioxide turns into a mild acid, carbonic acid, which interferes with the formation of shells of marine life and many other life processes in the ocean. When those shells fail to form, carbon dioxide previously
removed from the water by their formation instead increases in a self-inforcing manner. The greater the concentration gets, the worse the effects will be on marine life. It’s difficult to predict how mass death in the world’s oceans would affect land species like ourselves, but it is highly doubtful it would be anything but negative.
The study cited above demonstrates the possibility that beyond a certain concentration, the carbonic acid triggers a cascade of change in ocean chemistry similar to that believed to have occurred during previous mass extinction events. Given the current pace of acidification, the world’s oceans are likely to reach this trigger point by the end of the century.
