High level of carbon dioxide is associated with high ambient temperatures, or retreating glaciers. This discovery has other consequences. Most of the carbon dioxide is actually stored in the oceans, and there is a continuous exchange of carbon dioxide between air, land, and the oceans. Thus it seems plausible that the oceans should be considered in the study of dramatic global climatic changes, as they occured during the ice ages. There is also a much less abundant isotope of oxygen, Oxygen-18, with 8 protons and 10 neutrons.
Cold air holds less moisture than warm air.
Thus, during the ice ages, there would have been less Oxygen-18 in the air and more in the oceans. Foraminifera are simple organisms which inhabit shells. When they die and fall to the ocean bottoms, their debris retain the signature of the composition of seawater at that time. This page was produced by Gianfranco Vidali.