Calcium carbonate cycling in future oceans and its influence on future climates

In the last few years, evidence has accumulated that calcifying organisms are likely to be affected by ocean acidification. Therefore, the production of calcium carbonate will probably decline, although conversely global warming, increasing stratification and sea level rise may also stimulate increases in global calcification. As acidification reaches the deep ocean, it will cause pronounced shallowing of the lysocline depths for calcite and aragonite, leading most probably to an almost complete cessation of deep-sea calcium carbonate burial for some centuries. Here, I briefly review the consequences of these and other changes on future ocean calcium carbonate cycling, and the consequences of this for future climate. Associated climate impacts are not likely to be significant over the next few centuries, but will become increasingly important thereafter. After the carbonate compensation response to acidification has run its course, extra CO2 is expected to be left behind in the atmosphere, protecting against future ice ages.