John Shepherd

Letter to The Times (8 Nov 2010) about Matt Ridley’s article on Ocean Acidification

Sir,

Matt Ridley should brush up his basic chemistry & biology before he criticises scientists who worry about ocean acidification.
First, any shift of acidity is still important even if it is (just) within natural ranges; and in the future it will be much larger than that.
Second, it has been known for some time that some organisms may make shells starting from bicarbonate ions.  But there is abundant evidence that dissolution of their shells is controlled by the carbonate ion concentration, so decreases in carbonate means a problem for retention of shells.
Third, Ridley’s claim of “no significant mean effect” of predicted future CO2 levels is only true because that is an average over several processes and many species – among which there will certainly be winners and losers.
Overall, decrease in calcification rate means a change in the ecosystem structure, and probably its function too, with unpredictable consequences.  We entirely agree that that the jury is out on how damaging acidification will be, but the scientific community is right to be concerned to research this “other CO2 problem”.

Professor John Shepherd FRS, University of Southampton
Professor John Raven FRS, University of Dundee
Professor Andrew Watson FRS, University of East Anglia

See also the more detailed responses from others here and here