International
via Norwegian Institute for Water Research (NIVA)

World - Ocean acidification and human health

While ocean acidification was initially perceived as a threat only to the marine realm, the authors of a new publication argue that it is also an emerging human health issue.

The global threats from carbon dioxide (CO2) accumulating in the world's oceans and driving ongoing ocean acidification are becoming increasingly evident. As humans extract and burn fossil fuels and drive deforestation, CO2in the atmosphere increases, with levels now far exceeding those that occurred in preindustrial times.

Of the released CO2, around 25% is taken up by the oceans where it interacts with seawater and forms carbonic acid, leading to a reduction in pH, an increase in acidification, and an alteration of carbonate chemistry. The average surface pH of the ocean has already decreased by 0.1 unit since the beginning of the Industrial Revolution, and a further 0.3–0.4 unit decrease is expected by the end of the century. As pH is measured on the logarithmic scale, this corresponds to a doubling in acidity by 2100. These changes are happening at an unprecedented scale and speed, rapidly exposing marine ecosystems to conditions they have not experienced over millions of years.

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