Tuesday, June 26, 2018

Carbon Capture: ocean plants

The ocean has absorbed approximately a third of the extra carbon released since the industrial age. When carbon dioxide is absorbed by seawater it becomes carbonic acid, leading to the gradual acidification of the oceans.

There are several methods proposed by which the carbon stored in the ocean can be more rapidly sequestered, reducing carbonic acid levels (though the ocean would promtly absorb more carbon from the atmosphere):

  • alkalinization: to counteract the carbonic acid by adding huge quantities of alkalines to the ocean, such as bicarbonate. Quite usefully, bicarbonate can be produced via the Calcium Loop, by breaking apart the calcium carbonate into bicarbonate instead of heating it to release concentrated carbon dioxide.
  • fertilization: the carbon in the oceans could be handled by encouraging phytoplankton to grow. Different parts of the ocean contain phosphorous, nitrogen, and iron in differing amounts. By adding these three in the correct ratio, phytoplankton will be enabled to consume more carbon.

The main issue with these ideas is that they are not self-funding, they do not produce an output which can be used to generate revenue to continue the effort. These kinds of projects would depend on massive external support, as by governments or the (very) wealthy.