Greenhouse gasses raise temperatures of Earth’s atmosphere by absorbing the heat of the sun’s radiation.  Carbon Dioxide levels rose to eight times that of our modern atmosphere during the late Cretaceous period, and as result rose Earth’s temperature 9^O (F).  The surplus of toxic gasses within the atmosphere, aside from warming, had other effects upon the biosphere of the late cretaceous.  Carbon dioxide, a prominent and controversial greenhouse gas today, has always threatened species with increasing atmospheric levels.  Earth’s biosphere employs mechanisms of greenhouse gas abortion, though high levels of gasses can override nature’s ability to keep the atmosphere composition at habitable proportions.

Large bodies of water, typically oceans, absorb oxygen and carbon dioxide molecules removing them from the atmosphere.  This process occurs at the water’s surface, where microscopic plankton and such organisms reside and absorb carbon dioxide.  These plankton, whose skeleton’s fall to the ocean floor, offer calcium carbonate that functions as shells, offering habitats to small organisms that live on the ocean bottom.  As atmospheric levels of CO2 rise, so do oceans (acidity):

“When CO2 dissolves in seawater it forms a weak acid, called carbonic acid.  Part of this acidity is neutralised by the buffering effect of seawater, but the overall impact is to increase the acidity. This dissolution of CO2 has lowered the average pH of the oceans by about 0.1 units from pre-industrial…  Such a value may seem small but because of the way pH is measured, as we explain in Section 2, this change represents about a 30% increase in the concentration of hydrogen ions, which is a considerable acidification of the oceans.  Increasing atmospheric concentration of CO2 will lead to further acidification of the oceans.” (The Royal Party, 9).

This renders the oceans’ microorganisms obsolete, organisms prominent in the role of carbon dioxide absorption (resultant in calcium carbonate, CaC0³).  The hindering of these microorganisms, as well as the loss of plant life, allowed carbon dioxide and the greenhouse gasses to amount rapidly without the checks and balances of a stable ecosystem.