760 NATURE CLIMATE CHANGE | VOL 2 | OCTOBER 2012 | www.nature.com/natureclimatechange In the version of this Letter originally published, the unit on the right-hand y axis of Figure 2a and Supplementary Figures S3b, S5b, S7b, S9b and S11b should have read gC m -3 . Tis error has now been corrected in the HTML and PDF versions of the Letter. Changes in pH at the exterior surface of plankton with ocean acidification Kevin J. Flynn, Jerry C. Blackford, Mark E. Baird, John A. Raven, Darren R. Clark, John Beardall, Colin Brownlee, Heiner Fabian & Glen L. Wheeler Nature Climate Change 2, 510–513 (2012); published online 15 April 2012; corrected afer print 7 September 2012. CORRIGENDUM ARTICLES NATURE CLIMATE CHANGE DOI: 10.1038/NCLIMATE1696 © 2012 Macmillan Publishers Limited. All rights reserved