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gwennoda on 2011-08-08The 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 at the 2009 United Nations Climate Change Conference (COP15) as the “evil twin of climate change”.
The oceans 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 to the oceans - 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, scientists find there is still a lack of understanding.