The term ocean acidification is used to describe the ongoing
decrease in ocean pH caused by human CO2 emissions, such
as the burning of fossil fuels. It is the little known consequence
of living in a high CO2 world, dubbed as the “evil twin
of climate change”.
currently absorb approximately half of the
CO2 produced by burning fossil fuel; put simply,
climate change would be far worse if it were not for the oceans.
However, there is a cost; when CO2 dissolves in seawater
it forms carbonic acid and as more CO2 is taken up
by the oceans surface, the pH decreases, moving towards a less
alkaline and therefore more acidic state.
Already ocean pH has decreased by about 30% and if we continue
emitting CO2 at the same rate by 2100 ocean
acidity will increase by about 150%, a rate that has not been
experienced for at least 400,000 years. Such a monumental
alteration in basic ocean chemistry is likely to have wide
implications for ocean life, especially for those organisms that
require calcium carbonate to build shells or skeletons.
Ocean acidification is a relatively new field of
research, with most of the studies having been conducted over the
last decade. While it is gaining some attention among policy
makers, international leaders and the media, there is
still much to be understood about the issue itself, how it
will effect the marine environment and the subsequent impact upon
The UK Ocean Acidification Research Programme (UKOA) works
alongside the international partner programmes Biological Impacts of Ocean Acidification
(BIOACID), European Project on Ocean Acidification (EPOCA),
Mediterranean Sea Acidification
in a changing climate (MedSeA) and U.S. Ocean Carbon and Biogeochemistry