With Speed and Violence Fred Pearce - Global Commons Institute

may already be happening. In 2003, the NASA scientist Watson Gregg
published satellite measurements suggesting that the biological productivity
of the oceans may have fallen by 6 percent since the 1980s. It could be part
of a natural cycle, he said, but it could also be an early sign that the biological
pump is slowing as ocean temperatures rise.
So far, since the beginning of the Industrial Revolution, the oceans have
absorbed from the atmosphere something like 130 billion tons of carbon
resulting from human activities. While much of it has fallen to the seabed, a
considerable amount remains dissolved in ocean waters—with a singular
and rather remarkable effect: it is making the oceans more acid.
The carbonic acid produced by dissolving carbon dioxide is corrosive and
especially damaging to organisms that need calcium carbonate for their
shells or skeletons. These include coral, sea urchins, starfish, many shellfish,
and some plankton. Besides eating away at the organisms, the acid reduces
the concentration of carbonate in the water, depriving them of the chemicals
they need to grow.
Acidity, measured as the amount of hydrogen ions in the water, is already
up by 30 percent. To put it another way, the pH has dropped by 0.1 points,
from 8.2 to about 8.1. If the oceans continue to absorb large amounts of the
atmosphere's excess carbon dioxide, acidification will have more than
tripled by the second half of this century, badly damaging ocean ecosystems.
The most vulnerable oceans are probably the remote waters of the Southern
Ocean and the South Pacific. They are distant from land, and so are already
short of carbonate—in particular a form known as aragonite, which seems to
be the most critical.