text: A paper published today in Biogeosciences finds that prior claims about the effects of ocean "acidification" on c alcifying plankton are highly exaggerated because the artificial laboratory conditions utilized do not correctly simulate the effects in naturalseawater. The authors find exposure of the plankton to "acidific ation" from elevated CO2 concentrations of up to 3247 ppm had no effect on the life cycle (population density, growth and reproduction) of calcifying plankton when natural buffering sediment was present in the experiment.