Ocean acidification – where the ocean becomes less alkaline as it absorbs excess CO2from the atmosphere – has been described as the evil twin of global warming. Yet, remarkably, it is only over the past decade that scientists have started to recognise the very real threat it poses to coral reefs and other marine ecosystems.
As late as 2004, a survey conducted among coral reef scientists revealed ocean acidification was ranked 36th out of 39 identified threats to coral reefs, well below other threats such as tourism, scientific research and the aquarium trade.
Fast-forward to 2013 and it is widely recognised that ocean acidification is becoming one of the top threats to coral reefs. The surface ocean has already taken up approximately one-quarter of the anthropogenic CO2 emitted into the atmosphere, leading to increasing acidity.
Atmospheric CO2 will only increase from here, so the impacts of these chemical changes to coral reef organisms and ecosystems in the future are likely to be significant.
Worryingly, new research suggests that we may still be underestimating the size of the impact and how soon irreversible damage could occur.