Ocean acidification describes the ongoing
decrease in the pH of the Earth’s oceans, caused by
their uptake of anthropogenic carbon dioxide from the atmosphere.
Anthropogenic effects or processes are those derived from
human activities, as opposed to effects or processes that
occur in the natural environment without human influences.
Between 1751 and 2004 surface ocean pH is estimated to have
dropped from 8.25 to 8.14. While the full ecological consequences
of these changes are still uncertain, it appears likely that
calcifying species will be adversely affected.
Present evidence suggests that dramatic changes in the marine
environment over the next 100-200 years can be avoided only
with early and deep reductions in carbon dioxide emissions.