This is an experiment where he puts dry ice, frozen CO2, carbon dioxide into water that has a lot of calcium ions in it. At first the dry ice causes the water to turn milky, as the CO2 combines to form calcium carbonate.
Calcium carbonate is the compound found in sea shells. The sea creatures make their shell out of the calcium that is dissolved in the water as they grow. The sea shell stuff, calcium carbonate is formed as the CO2 bubbles through the water.
But as the CO2 in the water increases, the calcium carbonate dissolves back into the water. When too much CO2 dissolves in the water, the water becomes acidic. And sea shells dissolve in the presence of acid.
So if the ocean water becomes acidified by CO2 the sea shells dissolve. But very young sea creatures cannot use the calcium carbonate in the water to make their shells, so they cannot live. Other marine life that depend on the tiny shelled creatures for food can no longer live. This ocean acidification causes the marine life to die.
A YouTube short clip less than 1 minute
