Response on behalf of UK Ocean Acidification Research Programme (UKOARP)1
Summary
Matt Ridley‟s Opinion article (www.thetimes.co.uk/tto/opinion/columnists/article2793749.ece; paywall applies) is correct in identifying that there are uncertainties and some contradictory evidence regarding biological responses to future ocean acidification (which, chemically, is an inevitable consequence of increasing carbon dioxide levels in the atmosphere). However, for several aspects the article over-simplifies complex issues, or is inaccurate, or is potentially misleading. In particular, small changes in pH do result in large changes in acidity, and negative effects of ocean acidification on calcification are well-documented.
One important and undisputed fact is not mentioned at all. The calcium-based shells and other structures of organisms such as corals and molluscs slowly dissolve in seawater that is under-saturated in calcium carbonate. This effect can occur (and already does) in alkaline water with pH values considerably greater than 7.0, and will be increased by ocean acidification.
Ridley‟s conclusion that ocean acidification will either be beneficial or have no overall biological effect is a simplistic and invalid interpretation of the evidence. Whilst changes in ocean CO2, pH and carbonate chemistry will undoubtedly result in winners as well as losers, the calculation of an overall average response is scientifically flawed. That is because positive and negative impacts do not cancel out, but both contribute to ecosystem perturbation. It is also flawed from a human perspective, since an increase in (say) marine algae, bacteria or jellyfish would not provide socio-economic compensation for a decrease in (say) shellfish and corals. Both changes could be „bad news‟ from a human perspective. The magnitude of ocean acidification effects on key ecosystem components is, however, still uncertain – which is why the UK has an ocean acidification research programme, co-funded by NERC, Defra and DECC, and why there are also significant research investments by the EU, Germany, the US and others.
